Abstract
Background
Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, coronal crack or fracture, or dental trauma. Successful RoCT is characterised by an absence of symptoms (i.e. pain) and clinical signs (i.e. swelling and sinus tract) in teeth without radiographic evidence of periodontal involvement (i.e. normal periodontal ligament). The success of RoCT depends on a number of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. RoCT can be carried out with a single‐visit approach, which involves root canal system obturation (filling and sealing) directly after instrumentation and irrigation, or with a multiple‐visits approach, in which the treatment is completed in two or more sessions and obturation is performed in the last session. This review updates the previous versions published in 2007 and 2016.
Objectives
To evaluate the benefits and harms of completion of root canal treatment (RoCT) in a single visit compared to RoCT over two or more visits, with or without medication, in people aged over 10 years.
Search methods
We used standard, extensive Cochrane search methods. The latest search date was 25 April 2022.
Selection criteria
We included randomised controlled trials and quasi‐randomised controlled trials in people needing RoCT comparing completion of RoCT in a single visit compared to RoCT over two or more visits.
Data collection and analysis
We used standard Cochrane methods. Our primary outcomes were 1. tooth extraction and 2. radiological failure after at least one year (i.e. periapical radiolucency). Our secondary outcomes were 3. postoperative and postobturation pain; 4. swelling or flare‐up; 5. analgesic use and 6. presence of sinus track or fistula after at least one month. We used GRADE to assess certainty of evidence for each outcome.
We excluded five studies that were included in the previous version of the review because they did not meet the current standard of care (i.e. rubber dam isolation and irrigation with sodium hypochlorite).
Main results
We included 47 studies with 5805 participants and 5693 teeth analysed. We judged 10 studies at low risk of bias, 17 at high risk of bias and 20 at unclear risk of bias.
Only two studies reported data on tooth extraction. We found no evidence of a difference between treatment in one visit or treatment over multiple visits, but we had very low certainty about the findings (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.09 to 2.50; I2 = 0%; 2 studies, 402 teeth). We found no evidence of a difference between single‐visit and multiple‐visit treatment in terms of radiological failure (RR 0.93, 95% CI 0.81 to 1.07; I2 = 0%; 13 studies, 1505 teeth; moderate‐certainty evidence).
We found evidence of a higher proportion of participants reporting pain within one week in single‐visit groups compared to multiple visit groups (RR 1.55, 95% CI 1.14 to 2.09; I2 = 18%; 5 studies, 638 teeth; moderate‐certainty evidence).
We found no evidence of a difference in the proportion of participants reporting pain until 72 hours postobturation (RR 0.97, 95% CI 0.81 to 1.16; I2 = 70%; 12 studies, 1329 teeth; low‐certainty evidence), pain intensity until 72 hours postobturation (mean difference (MD) 0.26, 95% CI −4.76 to 5.29; I2 = 98%; 12 studies, 1258 teeth; low‐certainty evidence) or pain at one week postobturation (RR 1.05, 95% CI 0.67 to 1.67; I2 = 61%; 9 studies, 1139 teeth; very low‐certainty evidence). We found no evidence of a difference in swelling or flare‐up incidence (RR 0.56 95% CI 0.16 to 1.92; I2 = 0%; 6 studies; 605 teeth; very low‐certainty evidence), analgesic use (RR 1.25 95% CI 0.75 to 2.09; I2 = 36%; 6 studies, 540 teeth; very low‐certainty evidence) or sinus tract or fistula presence (RR 1.00, 95% CI 0.24 to 4.28; I2 = 0%; 5 studies, 650 teeth; very low‐certainty evidence).
Subgroup analysis found no differences between single‐visit and multiple‐visit RoCT for considered outcomes other than proportion of participants reporting post‐treatment pain within one week, which was higher in the single‐visit groups for vital teeth (RR 2.16, 95% CI 1.39 to 3.36; I2 = 0%; 2 studies, 316 teeth), and when instrumentation was mechanical (RR 1.80, 95% CI 1.10 to 2.92; I2 = 56%; 2 studies, 278 teeth).
Authors' conclusions
As in the previous two versions of the review, there is currently no evidence to suggest that one treatment regimen (single‐visit or multiple‐visit RoCT) is more effective than the other. Neither regimen can prevent pain and other complications in the 12‐month postoperative period. There was moderate‐certainty evidence of higher proportion of participants reporting pain within one week in single‐visit groups compared to multiple‐visit groups. In contrast to the results of the last version of the review, there was no difference in analgesic use.
Keywords: Aged; Humans; Analgesics; Analgesics/therapeutic use; Dentition, Permanent; Pain; Pain/drug therapy; Root Canal Therapy; Root Canal Therapy/adverse effects; Root Canal Therapy/methods; Tooth Extraction
Plain language summary
Should root canal treatment be performed in one dental visit or over several visits?
Key messages
Single‐visit and multiple‐visit endodontic (root canal) treatments are equally effective, regardless of whether the soft portion at the centre of the tooth containing nerves and blood vessels (dental pulp) is vital (living) or non‐vital (dead).
Both treatment approaches are frequently associated with some short‐term post‐treatment pain.
What is root canal treatment?
Root canal treatment is a common procedure in dentistry that is required when the dental pulp is irreversibly damaged. Root canal treatment is considered successful when there are no symptoms (such as pain), when x‐rays show no signs of damage to bone and other supporting tissues of the tooth, and when there are no gum signs of infection (such as swelling or sinus tract (an abnormal channel)).
How are root canal treatments performed?
Root canal treatment can be carried out over one or more appointments. The tooth, after being isolated from saliva by placing a rubber sheet ('dam') around it, is opened through the crown (visible part of the tooth) using a drill, the pulp is accessed and removed. Then, the canal is disinfected before being sealed with a filling.
In the past these procedures were performed over two or more visits, putting a small amount of medicine in the canals in‐between visits to kill any remaining bacteria, but now single‐visit treatments without the use of any interappointment medication are often preferred.
What did we want to find out?
We wanted to find out if root canal treatment performed in a single visit was better, equal to or worse than root canal treatment over two of more visits in terms of success of the treatment and likelihood of complications after treatment.
What did we do?
We searched for studies that investigated success and complications of single‐visit versus multiple‐visit root canal treatment in permanent (adult) teeth. We combined the results of relevant studies and rated our confidence in the evidence, based on factors such as study methods and number of people tested.
What studies did we find?
We found 47 studies with 5805 participants. The studies compared root canal treatment performed at a single appointment with root canal treatment performed over two or more appointments on vital permanent teeth, non‐vital permanent teeth, or both. The biggest study involved 390 teeth and the smallest study involved 26 teeth. The studies were conducted in countries around the world, with the largest number (12) in India.
What did the studies show?
Whether teeth are treated in a single visit or multiple visits may have no effect on the likelihood of tooth extraction (removal), but we are very uncertain about the results (evidence from two studies). Single‐visit and multiple‐visit treatments do not seem to have a different outcome when they are judged using x‐rays taken one year after treatment (evidence from 13 studies).
Participants treated over multiple visits are probably less likely to experience pain in the first week after treatment starts than participants treated in a single visit (evidence from five studies).
There seems to be no difference between single‐ and multiple‐visit treatment for other outcomes (whether or not there is pain after filling and the intensity of that pain, use of painkillers, swelling, and whether or not there is sinus tract), but we are uncertain about these results.
What are the limitations of the evidence?
We are moderately confident in the conclusions regarding x‐ray success of the treatment after one year not differing according to whether it was done in a single visit or multiple visits. Likewise, we are moderately confident in the finding that pain during the first week after treatment is more likely with single‐visit treatment. However, it is possible there were some flaws in the way the studies were run that could have affected the results.
We are not confident about the results for the other outcomes because the evidence was based on a few cases and the results varied widely across the studies, some of which had flaws in the way they were run.
How up to date is this evidence?
This review updates our previous versions published in 2007 and 2016. We searched for evidence up to April 2022.
Summary of findings
Summary of findings 1. Single visit versus multiple visits for endodontic treatment of permanent teeth.
| Single visit compared to multiple visits for endodontic treatment of permanent teeth | ||||||
| Population: people receiving endodontic treatment of permanent teeth Setting: university dental clinics, dental hospitals, private dental practices Intervention: single‐visit treatment Comparison: multiple‐visit treatment | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of teeth/participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with multiple‐visit treatment | Risk with single‐visit treatment | |||||
| Tooth extraction | 21 per 1000 | 10 per 1000 (2 to 52) | RR 0.46 (0.09 to 2.50) | 402 (2 RCTs) | ⊕⊝⊝⊝ Very lowa | The evidence for the effect of single‐ versus multiple‐visit treatment on tooth extraction due to endodontic problems is very uncertain. |
| Radiological failure | 232 per 1000 | 216 per 1000 (188 to 249) | RR 0.93 (0.81 to 1.07) | 1505 (13 RCTs) | ⊕⊕⊕⊝ Moderateb | Single‐ and multiple‐visit treatment do not seem to be different in terms of radiological outcome at 1 year. |
| Pain (dichotomous) – post‐treatment pain (within 1 week) | 206 per 1000 | 320 per 1000 (235 to 431) | RR 1.55 (1.14 to 2.09) | 638 (5 RCTs) | ⨁⨁⨁⊝ Moderatec | Single‐visit treatment seems to be associated with a higher proportion of participants experiencing pain in the first week after single‐visit treatment compared to in the first week after the first session of multiple‐visit treatment. |
| Pain (dichotomous) – pain in the immediate postobturation period (until 72 hours postobturation) | 507 per 1000 | 492 per 1000 (411 to 588) | RR 0.97 (0.81 to 1.16) | 1329 (12 RCTs) | ⊕⊕⊝⊝ Lowd | The incidence of pain in the immediate postobturation period (until 72 hours) may not differ between single‐ and multiple‐visit treatment. Analysis of pain intensity from continuous data led to the same conclusion. |
| Pain (dichotomous) – postobturation pain at 1 week | 179 per 1000 | 188 per 1000 (120 to 299) | RR 1.05 (0.67 to 1.67) | 1139 (9 RCTs) | ⊕⊝⊝⊝ Very lowe | The evidence for the effect of single‐ versus multiple‐visit treatment on postobturation pain at 1 week is very uncertain. |
| Swelling or flare‐up | 27 per 1000 | 15 per 1000 (4 to 51) | RR 0.56 (0.16 to 1.92) | 605 (6 RCTs) | ⊕⊝⊝⊝ Very lowf | The evidence for the effect of single‐ versus multiple‐visit treatment on swelling or flare‐up is very uncertain. |
| Analgesic use | 149 per 1000 | 186 per 1000 (112 to 312) | RR 1.25 (0.75 to 2.09) | 540 (6 RCTs) | ⊕⊝⊝⊝ Very lowg | The evidence for the effect of single‐ versus multiple‐visit treatment on analgesic use is uncertain. |
| Presence of sinus tract or fistula | 9 per 1000 | 9 per 1000 (2 to 40) | RR 1.00 (0.24 to 4.28) | 650 (5 RCTs) | ⊕⊝⊝⊝ Very lowh | The evidence for the effect of single‐ versus multiple‐visit treatment on sinus tract or fistula formation is very uncertain. |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; RCT: randomised controlled trial; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded one level for risk of bias and two levels for imprecision. Results based on only two studies, one at high risk of bias. CIs were very wide. bDowngraded one level for risk of bias. Results based on 13 studies: three at low risk of bias, eight at high risk of bias and two at unclear risk of bias. cDowngraded one level for risk of bias. Results based on five studies: two at low risk of bias, one at high risk of bias and two at unclear risk of bias. dDowngraded one level for risk of bias and one level for inconsistency. Results based on 11 studies: four at low risk of bias, two at high risk of bias and five at unclear risk of bias. We detected significant heterogeneity. eDowngraded one level for risk of bias, one level for inconsistency and one level for imprecision. Results based on nine studies: four at low risk of bias, two at high risk of bias and three at unclear risk of bias. We detected significant heterogeneity. CIs were wide. fDowngraded one level for risk of bias and two levels for imprecision. Results based on six studies: three at low risk of bias and three at unclear risk of bias. CIs were very wide. gDowngraded one level for risk of bias and two levels for imprecision. Results based on six studies: three at low risk of bias, one at high risk of bias and two at unclear risk of bias. CIs were very wide. hDowngraded one level for risk of bias and two levels for imprecision. Results based on five studies: one at low risk of bias, three at high risk of bias and one at unclear risk of bias. CIs were very wide.
Background
Description of the condition
Tooth damage by caries, trauma or iatrogenic events can lead to pulp inflammation (pulpitis), subsequent necrosis (death of the pulp) and development of inflammation of the tissues around the root apex (apical periodontitis). These conditions can cause pain, swelling and impaired masticatory function. Root canal treatment (RoCT) is indicated to relieve symptoms, prevent or cure apical periodontitis and to avoid tooth extraction. When RoCT is performed in a previously treated tooth with already filled canals, it is called root canal retreatment or non‐surgical endodontic retreatment.
Description of the intervention
RoCT is a common procedure in dentistry that is performed to remove organic tissue, infected debris and pathogenic bacteria from the root canal system by means of mechanical instrumentation associated with copious irrigation with disinfectant agents. The cleaned canals are then filled with a suitable obturation material, usually gutta‐percha associated with a sealer. RoCT involves two approaches: over two or more visits or in single visit. In the first approach, before obturation, residual bacteria are eliminated or prevented from repopulating the root canal system by introducing an interappointment dressing into the root canal, generally falling into the following categories: phenolic derivatives (eugenol, camphorated para‐monochlorophenol, camphorated phenol, metacresyl acetate, beechwood creosote), aldehydes (formocresol), halides (iodine‐potassium iodide), calcium hydroxide, antibiotics or other combinations. The most popular intracanal medication currently in use is calcium hydroxide. Some studies have shown that calcium hydroxide fails to produce sterile root canals and even allows regrowth in some cases (Kvist 2004; Manzur 2007; Ørstavik 1991). However, even a negative culture before obturation gives no guarantee of healing in all cases (Trope 1999; Weiger 2000). The second approach aims to eliminate in one visit most of the bacteria from the root canal system and achieve a three‐dimensional obturation able to deprive the micro‐organisms of nutrition and the space required to survive and multiply (Weiger 2000). The antimicrobial activity of the sealer or the zinc ions of gutta‐percha can kill the residual bacteria (Siqueira 2000).
Endodontic techniques can claim many improvements through the use of rubber dam, magnifying devices, electronic apex locators and engine‐driven rotary nickel titanium files, which have improved the success rate of endodontic treatment (Ahmed 2014; Martins 2014; Wong 2015; Zanza 2021), and shortened the time needed for treatment (Peralta‐Mamani 2019). The basic biological rationale for achieving final success of RoCT consists primarily of eliminating micro‐organisms from the entire root canal system and preventing their recontamination. Different therapeutic procedures can be employed, depending upon the biological condition of the tooth being treated, its pathological state, clinician expertise, instrument availability and patient preference. Successful RoCT is characterised by the absence of symptoms and clinical signs of infection in a tooth without radiographic evidence of periodontal involvement (Friedman 2002). The success of RoCT depends on variables related to the preoperative condition of the tooth, as well as the endodontic procedures.
How the intervention might work
There may be several short‐ and long‐term complications after a RoCT (Battrum 1996). The former includes immediate postoperative inflammation of periradicular tissues associated with pain, either spontaneous or provoked. The correlation of postoperative pain with different variables, including the number of visits needed to complete RoCT, operative procedures, pulp vitality and dental anatomy has been the objective of numerous studies (Albashaireh 1998; DiRenzo 2002; Gambarini 1991; Soltanoff 1978). The main long‐term complications include the persistence of fistula or sinus tract, pain, or both, and no periapical radiographic healing. Several studies investigated the frequency of radiographic healing in teeth with preoperative periapical pathology compared single‐ and multiple‐visit approaches, employing interappointment medication (Katebzadeh 2000; Peters 2002; Soltanoff 1978; Trope 1999; Weiger 2000). But the results are mixed. Some studies have suggested that the use of different medications between visits can contribute to bacteria elimination (Fava 1995). Others emphasised the need to seal the endodontic space as quickly as possible (i.e. in a single visit), as temporary cements are unreliable in maintaining a good coronal seal between visits. Postoperative complications have been reported with both methods, varying from 5% in Abbott 2000 to more than 20% in Friedman 1995.
The advantage of single‐visit endodontic treatment is that both operators and patients want to save chair side time (Rudner 1981); moreover, it is less costly in most analyses (Schwendicke 2016), and it also might be more convenient for patients who have temporomandibular disorders and cannot endure long treatment periods (Wong 2014).
Multiple‐visit treatment though might be indicated if the patient cannot tolerate further time in the chair, if there is insufficient time available for the dentist to complete treatment to the requisite standard or if the canal continues to fill with blood and cannot be dried (Ørstavik 2019).
One of the most controversial issues in endodontics is whether an interappointment medication is really needed to improve disinfection and then enhance treatment outcomes. The main reason to use an interappointment medication is to allow time for the medication to diffuse and reach bacteria in those areas inaccessible to instruments and irrigants and maximise bacterial reduction to levels that are difficult to achieve in one visit (Vera 2012). Alternatively, one argument in favour of treating infected root canals in one visit is that residual bacteria surviving to chemo‐mechanical decontamination are entombed by obturation and die because a source of nutrients is denied (Peters 1995). Thus, the importance of an added antibacterial effect by an interappointment medication used in multiple‐visit treatment has been questioned.
Why it is important to do this review
Since the publication of the latest review update (Manfredi 2016), several further studies have been conducted. These more‐recent studies use contemporary techniques and instruments (e.g. mechanical shaping with NiTi files). In order to assess if and how the evolution of root canal practice has affected the outcomes of single‐visit versus multiple‐visit RoCT, a new comprehensive analysis of available evidence was needed.
Objectives
To evaluate the benefits and harms of completion of root canal treatment (RoCT) in a single visit compared to RoCT over two or more visits, with or without medication, in people aged over 10 years.
Methods
Criteria for considering studies for this review
Types of studies
We included randomised controlled trials and quasi‐randomised controlled trials (i.e. those using an alternative assignment based on, for example, birthdate). We also considered split‐mouth and split‐cluster studies. We excluded studies that did not measure and report at least one of our outcomes.
Types of participants
Participants aged 10 years or above who required RoCT. All participants had teeth with a completely formed apex and without internal resorption.
Types of interventions
RoCT in a single visit or multiple visits (i.e. two or more appointments). Root canal retreatment was also included. Treatments had to meet the current standard of care (rubber dam isolation, use of sodium hypochlorite as irrigant).
Any systemic medical treatment (antibiotics, non‐steroidal anti‐inflammatory drugs or analgesics) was to be the same in both groups.
Types of outcome measures
Primary outcomes
Tooth extraction (binary, yes/no).
Radiological failure after at least one year (i.e. the presence of any periapical radiolucency) (binary, yes/no). Table 2 summarises how we adapted the most common scales of radiological healing to a binary outcome.
1. Endodontic radiological success and failure: from scales to binary outcome.
| Classification | Success (binary) | Failure (binary) |
| Trope 1999; Ørstavik 1991; Ørstavik 1998 | PAI score 1 (normal periapical), PAI score 2 (bone structural changes) | PAI score 3 (structural changes with mineral loss), PAI score 4 (radiolucency), PAI score 5 (radiolucency with features of exacerbation) |
| Strinberg 1956 | Success: normal to slightly thickened periodontal ligament space < 1 mm, elimination of previous rarefaction, normal lamina dura in relation to adjacent teeth, no evidence of resorption | Questionable: increased periodontal ligament space > 1 mm and < 2 mm, stationary rarefaction or slight repair evident, increased lamina dura in relation to adjacent teeth, evidence of resorption) Failure (increased width of periodontal ligament space > 2 mm, lack of osseous repair within rarefaction or increased rarefaction, lack of new lamina dura, presence of osseous rarefactions in periradicular areas where previously none existed) |
| Katebzadeh 2000 | Healed: normal pattern of trabecular bone and normal width of periodontal ligament space | Improved: reduction in lesion size Failed: increased or no change in the lesion size |
| Halse 1986 | Healed: normal pattern of trabecular bone and normal width of periodontal ligament space | Increased width of the periodontal space, pathological findings |
| Kvist 2004; Peters 2002 | Success (A): width and contour of periodontal ligament is normal, or there is a slight radiolucent zone around apical | Uncertain (B): radiolucency is clearly decreased but additional follow‐up is not available Failure (C): there is an unchanged, increased or new periradicular radiolucency |
| Weiger 2000 | Complete healing: no clinical signs and symptoms, radiographically a periodontal ligament space of normal width | Incomplete healing: no clinical signs and symptoms, radiographically a reduction of the lesion in size or an unchanged lesion within an observation time of 4 years No healing: clinical signs and symptoms indicating an acute phase of apical periodontitis or radiographically a persisting lesion after a follow‐up time of 4–5 years or a new lesion formed at an initially uninvolved root of a multirooted tooth, or a combination of these |
| Gesi 2006 | Normal periapical condition or unclear apical condition (widened apical periodontal space or diffused lamina dura) | Presence of periapical radiolucency when there was a distinct radiolucent area associated with the apical portion of the root |
| Chu 2005; Petersson 1991 | Normal: normal appearance of the surrounding osseous structure | Apical periodontitis: periapical radiolucency observed Periapical status not classified: the quality of the radiograph was insufficient for examination of the periapical structure |
PAI: periapical index; Rx: radiological evaluation.
Secondary outcomes
Postoperative pain (binary, yes/no; continuous).
Swelling or flare‐up (binary, yes/no).
Analgesic use (binary, yes/no).
Presence of sinus tract or fistula after at least one month (binary, yes/no).
Search methods for identification of studies
Electronic searches
Cochrane Oral Health's Information Specialist conducted systematic searches in the following databases for randomised controlled trials and controlled clinical trials. There were no language, publication year or publication status restrictions.
Cochrane Oral Health's Trials Register (searched 25 April 2022) (Appendix 1)
Cochrane Central Register of Controlled Trials (CENTRAL; 2022, Issue 3) in the Cochrane Library (Appendix 2)
MEDLINE Ovid (1946 to 25 April 2022) (Appendix 3)
Embase Ovid (1980 to 25 April 2022) (Appendix 4)
Subject strategies were modelled on the search strategy designed for MEDLINE Ovid. Where appropriate, they were combined with subject strategy adaptations of the highly sensitive search strategies designed by Cochrane for identifying randomised controlled trials and controlled clinical trials (as described in the Cochrane Handbook for Systematic Reviews of Interventions (Lefebvre 2022)).
Searching other resources
Cochrane Oral Health's Information Specialist searched the following trial registries for ongoing studies.
US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (clinicaltrials.gov; searched 25 April 2022)
World Health Organization International Clinical Trials Registry Platform (apps.who.int/trialsearch; searched 25 April 2022)
The search terms can be found in Appendix 5.
We checked the references of the included studies and other systematic reviews to find additional studies. In particular, after checking the reference lists of two Chinese systematic reviews (Wang 2017; Zhang 2015), we found further Chinese studies not indexed in the databases we searched.
When necessary, we contacted the authors to identify any additional published or unpublished data.
We did not perform a separate search for adverse effects of interventions used, we considered adverse effects described in included studies only.
Data collection and analysis
Selection of studies
Two review authors (GM, MGan) independently examined the title and abstract (when available) of each article identified by the search strategy. Any disagreement was resolved involving a third review author (MM). The search was designed to be sensitive and included controlled clinical trials; these were filtered out early in the selection process if they were not randomised. Where studies appeared to meet the inclusion criteria for this review or where there were insufficient data in the title and abstract to make a clear decision, we obtained the full report. At least two review authors (from GM, MM, GL, MGan) assessed the full report to determine whether it met the inclusion criteria. We resolved any disagreements by discussion. We recorded studies rejected at this or subsequent stages in the Characteristics of excluded studies table, with the reason(s) for exclusion. See Figure 1 for a flow chart that summarises the results of the search.
1.
Study flow diagram: review update.
Data extraction and management
At least two review authors (from GM, MM, GL, MGan) independently extracted data using a specially designed data extraction form and entered them into a spreadsheet. At least two review authors (from GM, MM, GL, MGan) independently assessed the risk of bias in the included studies. We discussed any discrepancies to reach agreement. When necessary, we contacted study authors for clarification or missing information. For each trial, we recorded the following data.
Year of publication, country of origin, number of centres, source of study funding, recruitment period.
Details of the participants including demographic characteristics and criteria for inclusion and exclusion, type of tooth treated (vital or non‐vital) and reasons of the treatment, diagnostic criteria for pulpal or periapical disease, numbers randomised to each treatment group.
Details about the number of visits performed to treat the root canal (single or multiple), number of operators involved in the treatment, use of rubber dam and magnification loupes, type of canal shaping, type of irrigation, method used to establish the working length of the root canal, type of obturation of the canal. In the multiple visits approach, we also recorded the type of medication used in the interappointment period.
Details of pain management.
Details of the outcomes reported, including method of assessment and time(s) assessed.
Description of operators.
Assessment of risk of bias in included studies
At least two review authors (from GM, MM, GL, MGan) independently assessed the risk of bias of the included trials and any disagreement was resolved through discussion and consensus. We used the recommended approach for assessing risk of bias in studies included in Cochrane Reviews (Higgins 2011). We addressed six domains:
random sequence generation (selection bias);
allocation concealment (selection bias);
blinding of outcome assessment (detection bias);
incomplete outcome data (attrition bias);
selective reporting (reporting bias);
other bias.
Each domain in the RoB 1 tool includes one or more entries in the Characteristics of included studies table. Within each entry, we described what was reported to have happened in the study in sufficient detail to support a judgement about the risk of bias. We then assigned a judgement relating to the risk of bias for that entry of 'low', 'high' or 'unclear' risk of bias. After taking into account the additional information provided by the authors of the trials, we summarised the risk of bias in the studies as:
low risk of bias if we judged all domains assessed at low risk of bias;
unclear risk of bias if we judged all domains assessed to be at low or unclear risk of bias;
high risk of bias if we judged one or more domains assessed to be at high risk of bias.
We completed a risk of bias table for each included study (see Characteristics of included studies table), and presented results graphically by study and by domain across all studies (Figure 2; Figure 3).
2.
Risk of bias summary: review authors' judgements about each risk of bias item for each included study.
3.
Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
Measures of treatment effect
Our primary measures of intervention effect were tooth extraction due to endodontic problems and radiological failure after one year. We are aware that some radiographic lesions can require considerable time to heal and we consider the one‐year radiographic follow‐up a good measure of the treatment outcome. We dichotomised data on radiological healing when this was measured on ordinal scales (see Table 2 for details).
Our secondary outcomes were incidence of pain (within one week calculated from the single‐visit treatment or the first session of multiple‐visit treatment, up to 72 hours, at one week/two weeks/one month/12 months or more postobturation), presence of swelling or flare‐up, analgesic use and presence of sinus track or fistula. When secondary outcomes were recorded multiple times within the time range of interest, we used the highest value. We dichotomised ordinal scale data into 'no pain' and 'pain' values. We analysed dichotomous data by calculating risk ratios (RRs) and 95% confidence intervals (CIs). When pain was recorded as a continuous outcome, we analysed data by calculating mean differences (MDs) and 95% CIs.
Unit of analysis issues
The unit of statistical analysis was the treated tooth. In some studies multiple teeth were treated in the same participant. These studies were considered to be potentially affected by a risk of bias if the authors did not explicitly state that:
the teeth treated in the same participants were independently allocated to single‐visit or multiple‐visit groups by randomisation;
a sufficient time (at least one month) elapsed between the RoCTs (in order to avoid interference in the pain measurements).
If trials with clustering were analysed appropriately, we included them in meta‐analysis; if not, we reported them narratively.
Dealing with missing data
When raw data were not available, we obtained them by consulting tables and graphs, or by contacting the trial authors.
Assessment of heterogeneity
We assessed heterogeneity by inspection of the point estimates and CIs on the forest plots. We assessed the variation in treatment effects by means of Cochran's test for heterogeneity and quantified by the I2 statistic. We considered heterogeneity statistically significant if P < 0.1. An approximate guide to the interpretation of the I2 statistic given in the Cochrane Handbook for Systematic Reviews of Interventions is: 0% to 40% might not be important, 30% to 60% may represent moderate heterogeneity, 50% to 90% may represent substantial heterogeneity and 75% to 100% may represent very substantial ('considerable') heterogeneity (Higgins 2022).
Assessment of reporting biases
Only a proportion of research projects conducted are ultimately published in an indexed journal and become easily identifiable for inclusion in systematic reviews. Reporting biases arise when the reporting of research findings is influenced by the nature and direction of the findings of the research. We attempted to minimise potential reporting biases including publication bias, time lag bias, multiple (duplicate) publication bias and language bias in this review. We constructed a funnel plot if we found at least 10 studies evaluating one outcome. If there had been asymmetry in the funnel plot indicating possible publication bias, we would have undertaken statistical analysis using the methods introduced by Egger 1997 (continuous outcomes) and Rucher 2008 (dichotomous outcomes). We attempted to avoid time lag bias, multiple (duplicate) publication bias and language bias by conducting a detailed sensitive search, including searching for ongoing studies. We did not impose any restrictions on language, and we found translators for potentially relevant trials published in other languages.
Data synthesis
For each study, we sought and summarised data on the number of teeth in the intervention and control groups who manifested or caused the event (outcome) and the total number of teeth. We only conducted a meta‐analysis if there were studies of similar comparisons reporting the same outcome measures. We combined RRs for dichotomous data, and MDs for continuous data, using a random‐effects model in Review Manager 5 (Review Manager 2014).
Subgroup analysis and investigation of heterogeneity
We had planned subgroup analyses to investigate the relevance of pretreatment conditions (vital teeth versus necrotic teeth), pretreatment symptoms (symptomatic versus asymptomatic teeth), pretreatment radiographic periapical appearance (apical radiolucency versus no apical radiolucency), endodontic technique and antimicrobials employed (antimicrobial A versus antimicrobial B). Only data on pretreatment conditions (vital teeth versus necrotic teeth) and endodontic technique (manual versus mechanical NiTi instrumentation) were available for subgroup analysis.
Sensitivity analysis
We performed sensitivity analysis for each outcome, excluding studies at overall high or unclear risk of bias.
Summary of findings and assessment of the certainty of the evidence
Using GRADEpro GDT software (GRADEpro GDT), we produced Table 1 for the following outcomes: tooth extraction, radiological failure, incidence of pain (with one‐week post‐treatment, until 72 hours and one‐week postobturation), swelling or flare‐up, analgesic use and sinus tract or fistula. We assessed the certainty of the evidence with reference to study limitations, inconsistency, imprecision and indirectness (publication bias is also normally considered but we were unable to assess this for the main outcomes) (Atkins 2004), and explained our decisions using footnotes in the summary of findings table. The certainty of evidence was defined as high (no downgrade), moderate (downgraded one level), low (downgraded two levels) or very low (downgraded three levels or more).
Results
Description of studies
Results of the search
Our electronic searches identified 494 new records. After scanning the titles and abstracts of these references, we excluded 473 as not relevant to this review update. We retrieved full‐text versions of 21 potentially eligible papers and of further 42 studies found from searching other resources (see Searching other resources). In addition, we retrieved the previously included 25 studies to re‐examine them on the basis of the updated inclusion/exclusion criteria. After close reading, we excluded 41 studies (see Characteristics of excluded studies table). A total of 47 studies met the inclusion criteria for this review (Figure 1).
Note: we excluded five studies that were included in the previous version of the review because they did not meet the current standard of care (i.e. rubber dam isolation and irrigation with sodium hypochlorite) (see Excluded studies).
Included studies
For detail of the characteristics of each of the 47 included studies, see Characteristics of included studies table.
Trial designs
Forty‐six studies used a parallel‐group design; the other study used a split‐cluster design in which two teeth (which were not necessarily symmetrical) were randomised in each participant (de Castro Rizzi‐Maia 2016). Most studies had two treatment arms, but seven were multi‐arm: three studies had three arms and four studies had four arms. Erdem Hepsenoglu 2018 compared three groups: single‐visit treatment, two‐visit treatment using calcium hydroxide as intracanal dressing and two‐visit treatment using chlorhexidine gel. Gill 2016 and Trope 1999 compared single‐visit treatment, multiple‐visit treatment without intracanal medication, and multiple‐visit treatment with intracanal medication (calcium hydroxide). Chhabra 2017 compared single‐visit treatment using Apexit Plus sealer, single‐visit treatment using AH Plus sealer, two‐visit treatment using Apexit Plus sealer, and two‐visit treatment using AH Plus sealer. Markan 2021 compared single‐visit treatment using conventional K files, single‐visit treatment using Protaper Next files, multiple‐visit treatment using conventional K files and multiple‐visits treatment using Protaper Next files. Pragya 2016 compared single‐visit treatment in single‐rooted mandibular premolars, single‐visit treatment in mandibular molars, two‐visit treatment in single rooted mandibular premolar and two‐visit treatment in mandibular molars. Tarallo 2018 and Shubham 2021 compared single‐visit treatment with instrumentation performed 1 mm beyond the apical foramen; single‐visit treatment with instrumentation on foraminal working length; two‐visit treatment with instrumentation performed on foraminal working length; two‐visit treatment with instrumentation performed 1 mm beyond the apical foramen. In order to include such data in the meta‐analysis, we combined single‐visit arms and multiple‐visit arms, respectively. In the same meta‐analysis, we pooled data from studies that used or did not use a dressing.
Four studies reported that they had received research grants for the conduct of the study (de Castro Rizzi‐Maia 2016; Mulhern 1982; Penenis 2008; Risso 2008).
Settings
Twelve studies were conducted in India (Chhabra 2017; Dhyani 2022; Dorasani 2013; Gill 2016; Gupta 2021; Jethi 2021; Markan 2021; Patil 2016; Pragya 2016; Rao 2014; Singh 2012; Tarale 2013), six in China (Gui 2017; Qi 2011; Sun 2020; Wang 2010; Wang 2016; Wong 2015), six in Turkey (Erdem Hepsenoglu 2018; Ince 2009; Keskin 2015; Micoogullari Kurt 2018; Özcan 2021; Yoldas 2004), four in the USA (DiRenzo 2002; Mulhern 1982; Penenis 2008; Trope 1999), three in Pakistan (Akbar 2013; Rana 2019; Riaz 2018), three in Mexico (Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020), three in Brazil (de Castro Rizzi‐Maia 2016; Risso 2008; Tarallo 2018), two in Egypt (Abdurrahman 2019; Hebatallah 2019), two in Italy (Fonzar 2017; Gesi 2006), and one each in the Netherlands (Peters 2002), Jordan (Al‐Negrish 2006), Germany (Weiger 2000), Saudi Arabia (Alomaym 2019), Nepal (Shubham 2021), and Sweden (Molander 2007).
Forty‐one studies were performed in university, hospital or military dental clinics. Two were undertaken in private practice (Fonzar 2017; Gesi 2006). Four studies did not provide details about the setting (Dorasani 2013; Ince 2009; Mulhern 1982; Rao 2014).
Participants
The studies enroled 5805 participants and 5693 teeth were analysed.
The studies considered one tooth per participant, except for de Castro Rizzi‐Maia 2016, Dorasani 2013, Gill 2016, Jethi 2021, Micoogullari Kurt 2018, Molander 2007, Paredes‐Vieyra 2012, Qi 2011, Trope 1999, and Wong 2015. de Castro Rizzi‐Maia 2016 adopted a split‐cluster design: each of the 24 participants contributed two teeth randomly treated with either single‐visit or multiple‐visit RoCT (pain was not an outcome). Dorasani 2013 analysed 64 teeth in 43 participants (five participants contributed two teeth and one participant contributed three teeth). Gill 2016 treated 81 anterior teeth in 43 participants (pain was not an outcomes). Jethi 2021 treated 100 teeth in 92 participants (pain was an outcome). Micoogullari Kurt 2018 treated 90 maxillary anterior teeth in 80 participants (pain was an outcome). Molander 2007 treated 101 teeth in 94 participants and seven participants contributed with more than one tooth. Paredes‐Vieyra 2012 reported that 287 participants and 300 teeth were enrolled; they stated that 21 participants contributed more than one tooth, but according to these figures, no more than 13 participants could have contributed more than one tooth. Qi 2011 treated 232 teeth in 209 participants (pain was an outcome). Trope 1999 considered 102 teeth in 81 participants (61 participants had a single tooth, 18 had two teeth and two participants had three teeth). Wong 2015 treated 256 teeth from 228 participants (pain was an outcomes). For these 10 studies, the analysis was conducted at the level of the tooth. Excluding Paredes‐Vieyra 2012, there was no information regarding the time in between RoCTs when more than one tooth was treated in the same participant.
Twenty‐two studies included participants with necrotic teeth only (Abdurrahman 2019; Akbar 2013; Al‐Negrish 2006; Chhabra 2017; de Castro Rizzi‐Maia 2016; Dorasani 2013; Gill 2016; Hebatallah 2019; Micoogullari Kurt 2018; Molander 2007; Mulhern 1982; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008; Peters 2002; Rao 2014; Riaz 2018; Risso 2008; Tarallo 2018; Trope 1999; Weiger 2000). Eight studies included only participants with vital teeth (Dhyani 2022; Gesi 2006; Gui 2017; Jethi 2021; Pragya 2016; Sun 2020; Wang 2010; Wang 2016). Fifteen studies included both vital and non‐vital teeth (Alomaym 2019; DiRenzo 2002; Fonzar 2017; Gupta 2021; Ince 2009; Keskin 2015; Markan 2021; Paredes‐Vieyra 2020; Patil 2016; Qi 2011; Rana 2019; Shubham 2021; Singh 2012; Tarale 2013; Wong 2015). Erdem Hepsenoglu 2018 and Yoldas 2004 exclusively included retreatments.
Interventions
Most studies compared RoCT performed in a single‐visit with RoCT performed in two visits (Abdurrahman 2019; Akbar 2013; Al‐Negrish 2006; Alomaym 2019; Chhabra 2017; de Castro Rizzi‐Maia 2016; DiRenzo 2002; Dorasani 2013; Erdem Hepsenoglu 2018; Fonzar 2017; Gesi 2006; Gill 2016; Gupta 2021; Hebatallah 2019; Ince 2009; Jethi 2021; Keskin 2015; Micoogullari Kurt 2018; Molander 2007; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Patil 2016; Penenis 2008; Peters 2002; Pragya 2016; Rana 2019; Rao 2014; Riaz 2018; Risso 2008; Shubham 2021; Singh 2012; Sun 2020; Tarale 2013; Trope 1999; Wang 2010; Wang 2016; Weiger 2000; Yoldas 2004). In three studies, the multiple‐visit RoCT lasted three visits (Dhyani 2022; Gui 2017; Mulhern 1982). Two studies reported that multiple‐visit treatment had been performed in two or three appointments depending on satisfactory disinfection of the canal (Markan 2021) or the complexity of the RoCT (Wong 2015). One study did not specify the number of 'multiple' visits (Qi 2011).
In the multiple‐visit approach, 11 studies did not use any intracanal medications in the interappointment period (DiRenzo 2002; Hebatallah 2019; Ince 2009; Jethi 2021; Markan 2021; Mulhern 1982; Patil 2016; Pragya 2016; Rana 2019; Rao 2014; Singh 2012). Twenty‐nine studies medicated the root canals with calcium hydroxide (Akbar 2013; Al‐Negrish 2006; Chhabra 2017; de Castro Rizzi‐Maia 2016; Dhyani 2022; Dorasani 2013; Fonzar 2017; Gesi 2006; Gui 2017; Gupta 2021; Keskin 2015; Micoogullari Kurt 2018; Molander 2007; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Peters 2002; Qi 2011; Riaz 2018; Risso 2008; Shubham 2021; Sun 2020; Tarale 2013; Tarallo 2018; Wang 2010; Wang 2016; Weiger 2000; Wong 2015). Two studies used a medication composed of calcium hydroxide and chlorhexidine (Penenis 2008; Yoldas 2004). In Erdem Hepsenoglu 2018, one group used calcium hydroxide and another group chlorhexidine gel. In Gill 2016 and Trope 1999, one group used calcium hydroxide and another group had no medication placed. Abdurrahman 2019 used a triple antibiotic paste as the interappointment dressing. It was not clear if Alomaym 2019 used calcium hydroxide because the authors made contradicting statements.
Five studies used magnification loupes (Fonzar 2017; Micoogullari Kurt 2018; Penenis 2008; Peters 2002; Wong 2015).
Twenty‐five studies established working length using an electronic apex locator and x‐rays (Abdurrahman 2019; Chhabra 2017; Dhyani 2022; DiRenzo 2002; Gill 2016; Gui 2017; Gupta 2021; Hebatallah 2019; Jethi 2021; Keskin 2015; Markan 2021; Micoogullari Kurt 2018; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Patil 2016; Peters 2002; Rao 2014; Risso 2008; Shubham 2021; Sun 2020; Tarale 2013; Tarallo 2018; Yoldas 2004), seven using an electronic apex locator (de Castro Rizzi‐Maia 2016; Erdem Hepsenoglu 2018; Fonzar 2017; Penenis 2008; Qi 2011; Singh 2012; Wang 2010), and nine using x‐rays only (Akbar 2013; Al‐Negrish 2006; Dorasani 2013; Gesi 2006; Ince 2009; Mulhern 1982; Riaz 2018; Trope 1999; Weiger 2000). Six studies did not report information about working length evaluation (Alomaym 2019; Molander 2007; Pragya 2016; Rana 2019; Wang 2016; Wong 2015).
Thirteen studies performed canal shaping using conventional hand instruments (Abdurrahman 2019; Akbar 2013; Al‐Negrish 2006; Dorasani 2013; Gesi 2006; Gill 2016; Ince 2009; Micoogullari Kurt 2018; Peters 2002; Rana 2019; Risso 2008; Shubham 2021; Weiger 2000), 18 used a combination of hand files and NiTi rotary files (Alomaym 2019; Chhabra 2017; de Castro Rizzi‐Maia 2016; DiRenzo 2002; Erdem Hepsenoglu 2018; Fonzar 2017; Gupta 2021; Hebatallah 2019; Molander 2007; Özcan 2021; Paredes‐Vieyra 2012; Qi 2011; Rao 2014; Riaz 2018; Singh 2012; Tarale 2013; Wang 2010; Yoldas 2004), and nine used rotary NiTi files only (Dhyani 2022; Gui 2017; Keskin 2015; Patil 2016; Penenis 2008; Pragya 2016; Sun 2020; Wang 2016; Wong 2015). Markan 2021 and Paredes‐Vieyra 2020 treated a subgroup of participants with hand K files and another subgroup with NiTi rotary files. Jethi 2021 treated a subgroup of participants with hand NiTi files and another group with NiTi rotary files. Paredes‐Vieyra 2018 and Tarallo 2018 used hand files and reciprocating NiTi files. Mulhern 1982 and Trope 1999 did not describe canal shaping instrumentation in a satisfactory way, but, when Mulhern 1982 was published, only hand instrumentation was available.
Most studies performed canal obturation with gutta‐percha using the lateral condensation technique (Abdurrahman 2019; Akbar 2013; Al‐Negrish 2006; Alomaym 2019; Chhabra 2017; de Castro Rizzi‐Maia 2016; Dhyani 2022; DiRenzo 2002; Dorasani 2013; Gesi 2006; Gill 2016; Gupta 2021; Hebatallah 2019; Ince 2009; Keskin 2015; Markan 2021; Micoogullari Kurt 2018; Molander 2007; Mulhern 1982; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Patil 2016; Peters 2002; Qi 2011; Rana 2019; Rao 2014; Riaz 2018; Risso 2008; Shubham 2021; Singh 2012; Trope 1999; Wang 2010; Weiger 2000; Yoldas 2004). Five studies used the vertical condensation technique for canal obturation (Fonzar 2017; Jethi 2021; Penenis 2008; Sun 2020; Wang 2016). Erdem Hepsenoglu 2018, Tarale 2013, and Tarallo 2018 reported a non‐compaction technique with cold gutta‐percha cones and epoxy resin‐based sealer. Wong 2015 used a carrier‐based hot gutta‐percha technique. Gui 2017 and Pragya 2016 did not describe the technique used to obturate the canals with gutta‐percha and sealer.
All studies used sodium hypochlorite, with concentrations ranging from 0.5% to 5.25%. Eleven studies used ethylene‐diamine‐tetraacetic acid (EDTA) solution (Abdurrahman 2019; de Castro Rizzi‐Maia 2016; Fonzar 2017; Gill 2016; Jethi 2021; Keskin 2015; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Qi 2011; Riaz 2018; Tarallo 2018). Nine reported lubrication with EDTA gel (Abdurrahman 2019; Chhabra 2017; Dhyani 2022; Dorasani 2013; Hebatallah 2019; Jethi 2021; Penenis 2008; Singh 2012; Sun 2020). Risso 2008 used a combination of sodium hypochlorite, citric acid and sodium thiosulfate as irrigant. Chhabra 2017 and Shubham 2021 irrigated root canals with saline, sodium hypochlorite and chlorhexidine. Dorasani 2013 used sodium hypochlorite and saline. Erdem Hepsenoglu 2018 irrigated the canals with sodium hypochlorite, EDTA and distilled water. Gupta 2021, Markan 2021, and Pragya 2016 irrigated with sodium hypochlorite, EDTA and saline. Micoogullari Kurt 2018, Özcan 2021, and Tarale 2013 irrigated with sodium hypochlorite, EDTA, saline and chlorhexidine. Patil 2016 irrigated with sodium hypochlorite and saline.
Nineteen studies reported that a single operator performed RoCT (Abdurrahman 2019; Al‐Negrish 2006; Alomaym 2019; de Castro Rizzi‐Maia 2016; Dorasani 2013; Gill 2016; Gupta 2021; Jethi 2021; Markan 2021; Micoogullari Kurt 2018; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Patil 2016; Peters 2002; Risso 2008; Shubham 2021; Tarallo 2018; Trope 1999), while 12 studies involved two or more operators (DiRenzo 2002; Fonzar 2017; Gesi 2006; Ince 2009; Molander 2007; Mulhern 1982; Paredes‐Vieyra 2020; Penenis 2008; Wang 2010; Weiger 2000; Wong 2015; Yoldas 2004). Eight studies specified that trained or experienced operators conducted treatment (Ince 2009; Micoogullari Kurt 2018; Molander 2007; Paredes‐Vieyra 2020; Penenis 2008; Peters 2002; Wang 2010; Weiger 2000), while in three studies postgraduate students performed RoCT (DiRenzo 2002; Mulhern 1982; Risso 2008). Sixteen studies did not provide details about the operators (Akbar 2013; Chhabra 2017; Dhyani 2022; Erdem Hepsenoglu 2018; Gui 2017; Hebatallah 2019; Keskin 2015; Pragya 2016; Qi 2011; Rana 2019; Rao 2014; Riaz 2018; Singh 2012; Sun 2020; Tarale 2013; Wang 2016).
Outcomes
Only two studies only provided information on tooth extraction as an outcome measure (Fonzar 2017; Wong 2015).
Nineteen studies conducted post‐treatment radiological assessment (Chhabra 2017; de Castro Rizzi‐Maia 2016; Dorasani 2013; Fonzar 2017; Gesi 2006; Gill 2016; Gui 2017; Micoogullari Kurt 2018; Molander 2007; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Penenis 2008; Peters 2002; Qi 2011; Trope 1999; Wang 2016; Weiger 2000; Wong 2015), and data on the presence of periapical radiolucency after at least one year could be extracted from 13 studies (Analysis 1.2). Table 2 shows the methods we adopted to construct scales for radiological healing or failure.
1.2. Analysis.
Comparison 1: Single versus multiple visits for endodontic treatment of permanent teeth – primary outcomes, Outcome 2: Radiological failure
Forty‐one studies investigated postoperative pain (Abdurrahman 2019; Al‐Negrish 2006; Alomaym 2019; Chhabra 2017; de Castro Rizzi‐Maia 2016; Dhyani 2022; DiRenzo 2002; Dorasani 2013; Erdem Hepsenoglu 2018; Fonzar 2017; Gesi 2006; Gill 2016; Gui 2017; Gupta 2021; Hebatallah 2019; Ince 2009; Jethi 2021; Keskin 2015; Markan 2021; Micoogullari Kurt 2018; Mulhern 1982; Özcan 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Patil 2016; Penenis 2008; Pragya 2016; Qi 2011; Rana 2019; Rao 2014; Riaz 2018; Risso 2008; Shubham 2021; Singh 2012; Sun 2020; Tarale 2013; Tarallo 2018; Wang 2010; Wong 2015; Yoldas 2004). The methods for evaluating postoperative pain are detailed in the Characteristics of included studies table. Whenever possible, we dichotomised pain data into 'pain' or 'no pain' values. Twenty‐one studies recorded pain as a continuous variable measured by visual analogue scale (VAS) (Alomaym 2019; Dhyani 2022; DiRenzo 2002; Gupta 2021; Hebatallah 2019; Jethi 2021; Keskin 2015; Markan 2021; Micoogullari Kurt 2018; Özcan 2021; Patil 2016; Pragya 2016; Rana 2019; Rao 2014; Riaz 2018; Risso 2008; Singh 2012; Sun 2020; Tarale 2013; Tarallo 2018; Wang 2010). Five studies provided dichotomous data of post‐treatment pain within one week (calculated from the single‐visit treatment and from the first session of multiple‐visit treatment) (Abdurrahman 2019; Dhyani 2022; Gesi 2006; Mulhern 1982; Yoldas 2004). Twelve studies provided dichotomous data of postobturation pain within 72 hours, at one week, at two weeks, at one month and at 12 months or greater (12 studies within 72 hours: Abdurrahman 2019; Al‐Negrish 2006; Dhyani 2022; Erdem Hepsenoglu 2018; Gupta 2021; Ince 2009; Micoogullari Kurt 2018; Molander 2007; Pragya 2016; Rana 2019; Risso 2008; Wang 2010; nine studies at one week: Abdurrahman 2019; Al‐Negrish 2006; Dhyani 2022; Fonzar 2017; Gesi 2006; Mulhern 1982; Pragya 2016; Wang 2010; Wong 2015; two studies at two weeks: Fonzar 2017; Paredes‐Vieyra 2020; one study at one month: Dhyani 2022; two studies at 12 months or greater: de Castro Rizzi‐Maia 2016; Wong 2015). Twelve studies provided continuous data of postobturation pain within 72 hours and at one week (12 studies within 72 hours: DiRenzo 2002; Gupta 2021; Hebatallah 2019; Keskin 2015; Markan 2021; Özcan 2021; Patil 2016; Pragya 2016; Riaz 2018; Singh 2012; Tarale 2013; Wang 2010; 4 studies at one week: Hebatallah 2019; Markan 2021; Özcan 2021; Pragya 2016).
Ten studies examined the need for participants to take analgesics to relieve pain (Abdurrahman 2019; Dhyani 2022; Fonzar 2017; Gupta 2021; Mulhern 1982; Paredes‐Vieyra 2018; Pragya 2016; Rao 2014; Wang 2010; Yoldas 2004). Six studies provided data on analgesic use (Abdurrahman 2019; Dhyani 2022; Gupta 2021; Mulhern 1982; Wang 2010; Yoldas 2004).
Nineteen studies investigated the incidence of swelling or flare‐up (Akbar 2013; Al‐Negrish 2006; Alomaym 2019; Chhabra 2017; Dhyani 2022; DiRenzo 2002; Jethi 2021; Micoogullari Kurt 2018; Mulhern 1982; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Penenis 2008; Qi 2011; Rao 2014; Risso 2008; Wang 2010; Wang 2016; Yoldas 2004). Definitions of flare‐up varied (see Table 3). We considered only studies clearly indicating swelling as a specific outcome, not simply as one of the signs related to the tooth infection. Six studies provided data on swelling (DiRenzo 2002; Fonzar 2017; Micoogullari Kurt 2018; Mulhern 1982; Wang 2010; Wang 2016).
2. Definition of flare‐up in the included studies.
| Study | Definition of flare‐up |
| Akbar 2013 | Moderate‐to‐severe postoperative pain or moderate‐to‐severe swelling that begins 12–48 hours after treatment and lasts ≥ 48 hours |
| Al‐Negrish 2006 | Percentage of participants experiencing moderate‐to‐severe pain evaluated after 2 and 7 days |
| Dhyani 2022 | Severe uncontrollable amount of interappointment and postoperative pain, not relieved by medication, requiring an unscheduled visit to the dental surgery for active treatment |
| DiRenzo 2002 | Swelling that requires antibiotics and narcotic analgesics |
| Micoogullari Kurt 2018 | Pain or swelling (or both) not relieved by analgesics and requires unscheduled visit |
| Mulhern 1982 | Swelling |
| Paredes‐Vieyra 2018 | Discomfort difficult to bear (analgesics, if used, were ineffective in relieving the pain) |
| Paredes‐Vieyra 2020 | Swelling associated with pain that was not relieved by medication |
| Risso 2008 | Intensive pain (visual analogue scale > 4) |
| Wang 2010 | Swelling |
| Yoldas 2004 | Severe postoperative pain or occurrence of swelling or both |
Nine studies investigated the post‐treatment presence of fistula or sinus tract (Chhabra 2017; de Castro Rizzi‐Maia 2016; Dorasani 2013; Fonzar 2017; Gill 2016; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008; Wong 2015). Five studies provided data on the presence fistula or sinus track after at least one month after RoCT (de Castro Rizzi‐Maia 2016; Fonzar 2017; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008).
Excluded studies
After full‐text evaluation, we excluded 41 studies initially included on the basis of the title and abstract. Five studies (Albashaireh 1998; Ghoddusi 2006; Oginni 2004; Soltanoff 1978; Xiao 2010) included in the previous version of the review (Manfredi 2016) were excluded in this version on the basis of the updated inclusion/exclusion criteria. Reasons for exclusion are recorded in the Characteristics of excluded studies table. Twenty‐five excluded studies did not report isolation with a rubber dam.
Studies awaiting classification
There are no studies awaiting classification.
Ongoing studies
There are no ongoing studies.
Risk of bias in included studies
Based on the criteria used in the critical appraisal of the studies, we assessed 10 studies at overall low risk of bias (Abdurrahman 2019; Dhyani 2022; Fonzar 2017; Micoogullari Kurt 2018; Molander 2007; Özcan 2021; Shubham 2021; Singh 2012; Tarallo 2018; Wang 2010), 20 studies at unclear risk of bias (Akbar 2013; Alomaym 2019; de Castro Rizzi‐Maia 2016; DiRenzo 2002; Erdem Hepsenoglu 2018; Gesi 2006; Gui 2017; Gupta 2021; Hebatallah 2019; Ince 2009; Keskin 2015; Markan 2021; Mulhern 1982; Pragya 2016; Rana 2019; Riaz 2018; Sun 2020; Tarale 2013; Wang 2016; Weiger 2000), and the remaining 17 studies at high risk of bias (Al‐Negrish 2006; Chhabra 2017; Dorasani 2013; Gill 2016; Jethi 2021; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Paredes‐Vieyra 2020; Patil 2016; Penenis 2008; Peters 2002; Qi 2011; Rao 2014; Risso 2008; Trope 1999; Wong 2015; Yoldas 2004). See Figure 2.
Allocation
We assessed the generation of randomisation sequence as being at low risk of bias (if the rule for random allocation was clearly described) in 27 trials (57.4%), unclear risk (if the rule for random allocation was not clearly described) in 14 trials (29.8%) and high risk (if a quasi‐random allocation method was used) in six trials (12.8%).
The concealment of allocation was at low risk of bias (if the method used prevented foreknowledge of the forthcoming allocations) in 15 trials (31.9%), unclear risk (if the allocation concealment was not clearly described) in 28 (59.6%) and high risk (if allocation could be known or predicted in advance) in four (8.5%). See Figure 3.
Blinding
Participant‐reported outcomes could not be blinded. We assessed blinding of outcome assessment for radiographic outcomes as being at low risk of detection bias (if the x‐ray evaluator was blind to the treatment allocation) for 39 trials (83.0%), unclear (if it was not clear if the x‐ray evaluator was blind to the treatment allocation) for seven trials (14.9%), and high risk (if the X‐ray evaluator was not blind to the treatment allocation for one trial (2.1%)). See Figure 3.
Incomplete outcome data
The reported dropout rate ranged from 0% to 35% (Penenis 2008). We assessed 42 (89.4%) trials at low risk with regard to attrition bias, either due to no dropouts or dropouts being unlikely to influence findings (less than 15%). For five trials (10.6%), we considered the high dropout rates to put the studies at high risk of attrition bias. See Figure 3.
Selective reporting
Seven trials (14.9%) did not report one of the planned outcomes without providing any reason so we assessed them at high risk of reporting bias. We assessed the remaining 40 studies (85.1%) at low risk of bias. See Figure 3.
Other potential sources of bias
A potential source of bias was considered for studies in which multiple teeth were treated in the same participant. We judged six studies (12.8%) at high risk of other bias because they did not explicitly state that the participants were randomised a number of times equal to the number of teeth and that sufficient time (at least one month) had elapsed between the RoCTs (in order to avoid interference in pain measurement). The remaining studies were at low risk of other bias. See Figure 3.
Effects of interventions
See: Table 1
Primary outcomes
Tooth extraction (binary, yes/no)
Only two studies reported data on tooth extraction, one at low risk of bias (Fonzar 2017) and one at high risk of bias (Wong 2015). Both studies reported RoCT in vital or necrotic teeth using mechanical NiTi instrumentation. Combining the results, we found no evidence of a difference between groups (RR 0.46, 95% CI 0.09 to 2.50; I2 = 0%; 402 teeth; Analysis 1.1; Figure 4). Sensitivity analysis focused on the low risk of bias study had a similar result (RR 0.49, 95% CI 0.05 to 5.30; 182 teeth; Fonzar 2017). We judged the certainty of the evidence to be very low (Table 1).
1.1. Analysis.
Comparison 1: Single versus multiple visits for endodontic treatment of permanent teeth – primary outcomes, Outcome 1: Extraction due to endodontic problems
4.
Radiological failure after at least one year (i.e. the presence of any periapical radiolucency) (binary, yes/no)
We combined results from 13 studies (Dorasani 2013; Fonzar 2017; Gesi 2006; Gill 2016; Micoogullari Kurt 2018; Molander 2007; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008; Peters 2002; Trope 1999; Weiger 2000; Wong 2015). The studies followed up participants for one year (Dorasani 2013; Fonzar 2017; Gill 2016; Penenis 2008; Trope 1999), 18 months (Wong 2015), two years (Micoogullari Kurt 2018; Molander 2007; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018), or more than three years (Gesi 2006; Peters 2002; Weiger 2000). Three studies were at overall low risk of bias, two at unclear risk of bias and eight at high risk of bias. The radiological failure rate was based on binary data, that is, radiological healing versus lack of such healing; scores including more than two values were dichotomised according to the methods indicated in Table 2.
The studies, irrespective of the follow‐up duration, showed no difference in terms of radiological failure between groups and no heterogeneity (RR 0.93, 95% CI 0.81 to 1.07; I2 = 0%; 13 studies, 1505 teeth; Analysis 1.2; Figure 5). The certainty of the evidence was moderate (Table 1). Sensitivity analysis performed on three studies at low risk of bias corroborated the result (RR 0.98, 95% CI 0.84 to 1.14; I2 = 0%; 348 teeth; Fonzar 2017; Micoogullari Kurt 2018; Molander 2007).
5.
Forest plot of comparison: 1 Primary outcomes, outcome: 1.2 Radiological failure.
In one study, not included in the meta‐analysis, the authors compared the one‐year reduction of periapical radiolucency by cone‐beam computed tomography in 13 teeth treated in single visit with 13 teeth treated with two‐visits treatment and calcium hydroxide interappointment dressing (de Castro Rizzi‐Maia 2016). There was no evidence of a difference.
Necrotic teeth
For 10 studies, it was possible to analyse radiological failure for necrotic teeth only (Dorasani 2013; Gill 2016; Micoogullari Kurt 2018; Molander 2007; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008; Peters 2002; Trope 1999; Weiger 2000). Two studies were at overall low risk of bias, one at unclear risk of bias and seven at high risk of bias. Meta‐analysis of these studies showed no difference between groups, and there was low heterogeneity (RR 0.83, 95% CI 0.61 to 1.14; I2 = 14%; 924 teeth; Analysis 1.2; Figure 5).
Vital teeth
Only one study reported the rate of radiological failure in vital teeth at enrolment (Gesi 2006). The study was at unclear risk of bias. This study found no difference between groups (RR 1.19, 95% CI 0.40 to 3.55; 184 teeth; Figure 5; Analysis 1.2).
Hand instrumentation
Six studies reported radiological failure after at least one year in teeth treated with hand instrumentations (Dorasani 2013; Gesi 2006; Gill 2016; Micoogullari Kurt 2018; Peters 2002; Weiger 2000). One study was at overall low risk of bias, two at unclear risk of bias and three at high risk of bias. Meta‐analysis of these studies showed no difference between groups and no heterogeneity (RR 0.89, 95% CI 0.58 to 1.38; I2 = 0%; 475 teeth; Analysis 1.2; Figure 5).
Mechanical nickel–titanium instrumentation
Six studies reported radiological failure after at least one year in teeth treated with mechanical NiTi instrumentation (Fonzar 2017; Molander 2007; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008; Wong 2015). Two studies were at overall low risk of bias and four at high risk of bias. Meta‐analysis of these studies showed no difference between groups, and there was low heterogeneity (RR 0.93, 95% CI 0.71 to 1.23; I2 = 27%; 928 teeth; Analysis 1.2; Figure 5).
Secondary outcomes
Postoperative pain (within one week)
Five studies compared postoperative pain within one week (calculated from the first session in the multiple‐visit treatment group) (Abdurrahman 2019; Dhyani 2022; Gesi 2006; Mulhern 1982; Yoldas 2004). Two studies were at overall low risk of bias, two at unclear risk of bias and one at high risk of bias. Analysis of pooled data resulted in a higher proportion of participants reporting pain with treatment in a single visit, and there was low heterogeneity (RR 1.55, 95% CI 1.14 to 2.09; I2 = 18%; 638 teeth; Analysis 2.1). The certainty of the evidence was moderate (Table 1). Sensitivity analysis performed on two studies found no evidence of a difference (RR 1.77, 95% CI 0.87 to 3.63; I2 = 54%; 104 teeth; Abdurrahman 2019; Dhyani 2022).
2.1. Analysis.
Comparison 2: Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes, Outcome 1: Pain (dichotomous)
Necrotic teeth
Two studies compared postoperative pain within one week in necrotic teeth (Abdurrahman 2019; Mulhern 1982). One study was at overall low risk of bias and one at unclear risk of bias. Meta‐analysis of these studies showed no difference between groups and no heterogeneity (RR 1.01, 95% CI 0.55 to 1.84; I2 = 0%; 104 teeth; Analysis 2.1).
Vital teeth
Two studies compared postoperative pain within one week in vital teeth (Dhyani 2022; Gesi 2006). One study was at overall low risk of bias and one at unclear risk of bias. Meta‐analysis of these studies showed a higher proportion of participants reporting pain in single‐visit group and there was no heterogeneity (RR 2.16, 95% CI 1.39 to 3.36; I2 = 0%; 316 teeth; Analysis 2.1).
Hand instrumentation
Three studies compared post‐treatment pain within one week in teeth treated with hand instrumentation (Abdurrahman 2019; Gesi 2006; Mulhern 1982). One study was at overall low risk of bias and two at unclear risk of bias. Meta‐analysis of these studies found no evidence of a difference between groups and no heterogeneity (RR 1.23, 95% CI 0.77 to 1.98; I2 = 0%; 360 teeth; Analysis 2.1).
Mechanical nickel–titanium instrumentation
Two studies compared post‐treatment pain within one week in teeth treated with mechanical NiTi instrumentation (Dhyani 2022; Yoldas 2004). One study was at overall low risk of bias and one at high risk of bias. Meta‐analysis of these studies showed a higher proportion of participants reporting pain in the single‐visit group, and there was moderate heterogeneity (RR 1.80, 95% CI 1.10 to 2.92; I2 = 56%; 278 teeth; Analysis 2.1).
Pain in the immediate postobturation period (up to 72 hours postobturation)
Twelve studies reported pain incidence within 72 hours after canal obturation as a dichotomous outcome (Abdurrahman 2019; Al‐Negrish 2006; Dhyani 2022; Erdem Hepsenoglu 2018; Gupta 2021; Ince 2009; Micoogullari Kurt 2018; Mulhern 1982; Pragya 2016; Rana 2019; Risso 2008; Wang 2010). Four studies were at overall low risk of bias, six at unclear risk of bias and two at high risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 0.97, 95% CI 0.81 to 1.16; I2 = 70%; 1329 teeth; Analysis 2.1). The certainty of evidence was low (Table 1). Sensitivity analysis performed on four studies found no evidence of a difference (RR 1.34, 95% CI 0.91 to 1.98; I2 = 52%; 275 teeth; Abdurrahman 2019; Dhyani 2022; Micoogullari Kurt 2018; Wang 2010).
Twelve studies evaluated immediate postobturation pain as a continuous outcome (DiRenzo 2002; Gupta 2021; Hebatallah 2019; Keskin 2015; Markan 2021; Özcan 2021; Patil 2016; Pragya 2016; Riaz 2018; Singh 2012; Tarale 2013; Wang 2010). In all but one of these studies, canal instrumentation was carried out using motor‐driven NiTi files. In Markan 2021, two groups were treated with hand instrumentation and two groups with rotary NiTi files. In order to perform a meta‐analysis, we standardised the results of the VAS from a 170 mm scale to a 100 mm scale in five studies (DiRenzo 2002; Gupta 2021; Patil 2016; Pragya 2016; Tarale 2013), and from a 10 cm scale to 100 mm in six studies (Hebatallah 2019; Keskin 2015; Markan 2021; Özcan 2021; Riaz 2018; Wang 2010). Three studies at overall low risk of bias, eight at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was considerable heterogeneity (MD 0.26, 95% CI −4.76 to 5.29; I2 = 98%; 1258 teeth; Analysis 2.2). The certainty of evidence was low (Table 1). Sensitivity analysis performed on three studies corroborated the previous result (MD −0.35, 95% CI −2.65 to 1.94; I2 = 25%; 327 teeth; Özcan 2021; Singh 2012; Wang 2010).
2.2. Analysis.
Comparison 2: Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes, Outcome 2: Pain (continuous)
Necrotic teeth
Six studies reported immediate postobturation pain as a dichotomous outcome in necrotic teeth (Abdurrahman 2019; Al‐Negrish 2006; Ince 2009; Micoogullari Kurt 2018; Mulhern 1982; Risso 2008). Two studies were at overall low risk of bias, two at unclear risk of bias and two at high risk of bias. The pooled estimate from the studies showed no differences between groups in participants with necrotic teeth, and there was very low heterogeneity (RR 0.97, 95% CI 0.81 to 1.16; I2 = 2%; 569 teeth; Analysis 2.1).
Six studies evaluated pain in the immediate postobturation period in necrotic teeth as a continuous outcome (DiRenzo 2002; Hebatallah 2019; Özcan 2021; Patil 2016; Riaz 2018; Singh 2012). Two studies were at overall low risk of bias, three at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was moderate heterogeneity (MD −0.07, 95% CI −0.56 to 0.42; I2 = 31%; 343 teeth; Analysis 2.2).
Vital teeth
Four studies analysed immediate postoperative pain as a dichotomous outcome in teeth vital at enrolment (Dhyani 2022; Ince 2009; Pragya 2016 Wang 2010). Two studies were at overall low risk of bias and two at unclear risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 1.33, 95% CI 0.94 to 1.88; I2 = 68%; 402 teeth; Analysis 2.1).
Two studies analysed immediate postobturation pain as a continuous outcome in vital teeth (Patil 2016; Pragya 2016). One study was at unclear risk of bias and one at high risk of bias. There was no evidence of a difference in pain intensity between group, and no heterogeneity (MD 0.69, 95% CI −0.78 to 2.17; I2 = 0%; 130 teeth; Analysis 2.2).
Hand instrumentation
Seven studies reported immediate postobturation pain as a dichotomous outcome in teeth treated with hand instrumentation (Abdurrahman 2019; Al‐Negrish 2006; Ince 2009; Micoogullari Kurt 2018; Mulhern 1982; Rana 2019; Risso 2008). Two studies were at overall low risk of bias, three at unclear risk of bias and three at high risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 0.81, 95% CI 0.58 to 1.12; I2 = 59%; 709 teeth; Analysis 2.1).
Mechanical nickel–titanium instrumentation
Five studies reported immediate postobturation pain as a dichotomous outcome in teeth treated with mechanical NiTi instrumentation (Dhyani 2022; Erdem Hepsenoglu 2018; Gupta 2021; Pragya 2016; Wang 2010). Two studies were at overall low risk of bias and three at unclear risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 1.15, 95% CI 0.81 to 1.62; I2 = 83%; 467 teeth; Analysis 2.1).
Pain at one week
Nine studies reported pain at one‐week postobturation as a dichotomous outcome (Abdurrahman 2019; Al‐Negrish 2006; Dhyani 2022; Fonzar 2017; Gesi 2006; Mulhern 1982; Pragya 2016; Wang 2010; Wong 2015). Four studies were at overall low risk of bias, three at unclear risk of bias and two at high risk of bias. There was no evidence of a difference between groups, and there was considerable heterogeneity (RR 1.05, 95% CI 0.67 to 1.67; I2 = 61%; 1139 teeth; Analysis 2.1). The certainty of evidence was very low (Table 1). Sensitivity analysis performed on four studies corroborated the previous result (RR 1.07, 95% CI 0.50 to 2.28; I2 = 77%; 391 teeth; Abdurrahman 2019; Dhyani 2022; Fonzar 2017; Wang 2010).
Four studies reported pain at one‐week postobturation as a continuous outcome in 368 participants (Hebatallah 2019; Markan 2021; Özcan 2021; Pragya 2016). The mean value of pain was zero in both single‐visit and multiple‐visit groups in Özcan 2021 and Pragya 2016, the multiple‐visit group of Hebatallah 2019, and the single‐visit group of Markan 2021. For the single‐visit group in Hebatallah 2019, the mean pain intensity at one week was 0.04 (standard deviation (SD) 0.02), and for the multiple‐visit group in Markan 2021, the mean pain intensity at one week was 0.3 (SD 2.34). Meta‐analysis and subgroup analysis of these studies were not possible (Analysis 2.2).
Necrotic teeth
Four studies evaluated the incidence of pain one week after the RoCT in necrotic teeth (Abdurrahman 2019; Al‐Negrish 2006; Gesi 2006; Mulhern 1982). One study was at overall low risk of bias, two at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was considerable heterogeneity (RR 1.52, 95% CI 0.24 to 9.41; I2 = 88%; 445 teeth; Analysis 2.1).
Vital teeth
Three studies reported the incidence of pain one week after RoCT in teeth vital at enrolment (Dhyani 2022; Pragya 2016; Wang 2010). Two studies were at overall low risk of bias and one at unclear risk of bias. There was no evidence of a difference in the frequency of pain between groups and no heterogeneity (RR 1.52, 95% CI 0.90 to 2.55; I2 = 0%; 249 teeth; Analysis 2.1).
Hand instrumentation
Four studies reported the incidence of pain at one week after RoCT executed with hand instrumentation (Abdurrahman 2019; Al‐Negrish 2006; Gesi 2006; Mulhern 1982). One study was at overall low risk of bias, two at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 0.82, 95% CI 0.47 to 1.42; I2 = 0%; 472 teeth; Analysis 2.1).
Mechanical nickel–titanium instrumentation
Five studies reported the incidence of pain one week after RoCT executed with mechanical NiTi instrumentation (Dhyani 2022; Fonzar 2017; Pragya 2016; Wang 2010; Wong 2015). Three studies were at overall low risk of bias, one at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 1.23, 95% CI 0.63 to 2.38; I2 = 78%; 667 teeth; Analysis 2.1).
Pain at two weeks
Two studies reported pain two weeks after canal obturation as a dichotomous outcome (Fonzar 2017; Paredes‐Vieyra 2020). One study was at overall low risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was substantial heterogeneity (RR 0.56, 95% CI 0.07 to 4.69; I2 = 83%; 288 teeth; Analysis 2.1). However, sensitivity analysis considering only the low risk of bias study showed a benefit for single‐visit treatment (RR 0.18, 95% CI 0.04 to 0.80; 199 teeth; Analysis 2.1; Fonzar 2017).
Pain at one month
One study reported pain one month after canal obturation as a dichotomous outcome (Dhyani 2022). The study was at overall low risk of bias. In this study, in which 60 teeth were vital at the time of enrolment and were treated with NiTi rotary files, no participant reported pain at one month (Analysis 2.1).
Pain at 12 months or more
Two studies reported incidence of pain at 12 and 18 months after RoCT (de Castro Rizzi‐Maia 2016; Wong 2015). One study was at overall unclear risk of bias and one at high risk of bias. In de Castro Rizzi‐Maia 2016, no participant reported pain. In Wong 2015, 1/117 participants in the single‐visit group and 1/103 participants in the multiple‐visit group reported pain (Analysis 2.1).
Swelling or flare‐up
We considered all studies reporting flare‐up as swelling and those where flare‐up was defined as swelling with or without moderate or intense pain. For definitions of flare‐up, see Table 3. We included six studies (DiRenzo 2002; Fonzar 2017; Micoogullari Kurt 2018; Mulhern 1982; Wang 2010; Wang 2016). Three studies were at overall low risk of bias and three at unclear risk of bias. There were only 12 events recorded: 4/306 in the single‐visit group and 8/299 in the multiple‐visits group. There was no evidence of a difference between groups and no heterogeneity (RR 0.56, 95% CI 0.16 to 1.92; I2 = 0%; 605 teeth; Analysis 2.3). The certainty of the evidence was very low (Table 1). Sensitivity analysis performed on three studies found no difference between groups (RR 0.42, 95% CI 0.05 to 3.17; I2 = 2%; 353 teeth; Fonzar 2017; Micoogullari Kurt 2018; Wang 2010).
2.3. Analysis.
Comparison 2: Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes, Outcome 3: Swelling or flare‐up
Necrotic teeth
Two studies reported data in necrotic teeth for 142 participants (Micoogullari Kurt 2018; Mulhern 1982). One study was at overall low risk of bias and one at unclear risk of bias. Mulhern 1982 recorded only two events of flare‐ups, both in the single‐visit group. Due to the extremely low number of events, no meta‐analysis could be performed (Analysis 2.3).
Vital teeth
Two studies reported data in vital teeth (Wang 2010; Wang 2016). One study was at overall low risk of bias and one at unclear risk of bias. There was no evidence of a difference between groups, and there was no statistical heterogeneity (RR 0.53, 95% CI 0.09 to 3.00; I2 = 0%; 209 teeth; Analysis 2.3).
Hand instrumentation
Two studies reported data in teeth treated with hand instrumentation for 142 participants (Micoogullari Kurt 2018; Mulhern 1982). One study was at overall low risk of bias and one at unclear risk of bias. Mulhern 1982 reported only two events of flare‐ups, both in the single‐visit group. Due to the extremely low number of events, no meta‐analysis could be performed (Analysis 2.3).
Mechanical nickel–titanium instrumentation
Four studies reported the incidence of flare‐up or swelling after RoCT executed with mechanical NiTi instrumentation (DiRenzo 2002; Fonzar 2017; Wang 2010; Wang 2016). Two studies were at overall low risk of bias and two at unclear risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 0.36, 95% CI 0.09 to 1.38; I2 = 0%; 463 teeth; Analysis 2.3).
Analgesic use
Six studies reported data on analgesic use (binary, yes/no) (Abdurrahman 2019; Dhyani 2022; Gupta 2021; Mulhern 1982; Wang 2010; Yoldas 2004). Three studies were at overall low risk of bias, two at unclear risk of bias and one at high risk of bias. There was no evidence of a difference in use of analgesics between groups, and there was moderate heterogeneity (RR 1.25, 95% CI 0.75 to 2.09; I² = 36%; 540 teeth; Analysis 2.4). The certainty of the evidence was very low (Table 1). Sensitivity analysis of the three studies at low risk of bias also found no evidence of a difference (RR 0.94, 95% CI 0.72 to 1.24; I2 = 0%; 193 teeth; Abdurrahman 2019; Dhyani 2022; Wang 2010).
2.4. Analysis.
Comparison 2: Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes, Outcome 4: Analgesic use
Necrotic teeth
Only two studies reported analgesic use in necrotic teeth (Abdurrahman 2019; Mulhern 1982). One study was at overall low risk of bias and one at unclear risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 1.29, 95% CI 0.52 to 3.19; I2 = 0%; 104 teeth; Analysis 2.4).
Vital teeth
Only two studies reported analgesic use in vital teeth (Dhyani 2022; Wang 2010). Both studies were at overall low risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 0.93, 95% CI 0.71 to 1.23; I2 = 0%; 149 teeth; Analysis 2.4).
Hand instrumentation
Only two studies reported analgesic use in teeth treated with hand instrumentation (Abdurrahman 2019; Mulhern 1982). One study was at overall low risk of bias and one at unclear risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 1.29, 95% CI 0.52 to 3.19; I2 = 0%; 104 teeth; Analysis 2.4).
Mechanical nickel–titanium instrumentation
Four studies reported analgesic use in teeth treated with NiTi mechanical instrumentation (Dhyani 2022; Gupta 2021; Wang 2010; Yoldas 2004). Two studies were at overall low risk of bias, one at unclear risk of bias and one at high risk of bias. There was no evidence of a difference between groups, and there was with substantial heterogeneity (RR 1.29, 95% CI 0.57 to 2.93; I2 = 61%; 436 teeth; Analysis 2.4).
Presence of sinus tract or fistula
Five studies reported the presence of sinus tract or fistula (de Castro Rizzi‐Maia 2016; Fonzar 2017; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008). The endodontic treatments were performed using NiTi mechanical instrumentation. One study was at overall low risk of bias, one at unclear risk of bias and three at high risk of bias. There were only six events recorded in these studies: 3/330 in the single‐visit group and 3/320 in the multiple‐visits group. There was no evidence of a difference between groups and no heterogeneity (RR 1.00, 95% CI 0.24 to 4.28; I2 = 0%; 650 teeth; Analysis 2.5). Sensitivity analysis based on low risk of bias found a similar result (RR 0.33, 95% CI 0.01 to 7.90; 182 teeth; Fonzar 2017). The certainty of evidence was very low (Table 1).
2.5. Analysis.
Comparison 2: Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes, Outcome 5: Presence sinus tract or fistula
Necrotic teeth
Four studies reported the presence of sinus tract or fistula after RoCT in necrotic teeth (de Castro Rizzi‐Maia 2016; Paredes‐Vieyra 2012; Paredes‐Vieyra 2018; Penenis 2008). One study was at overall unclear risk of bias and three at high risk of bias. There was no evidence of a difference between groups and no heterogeneity (RR 1.35, 95% CI 0.26 to 6.84; I2 = 0%; 468 teeth; Analysis 2.5).
Vital teeth
No study reported the presence of sinus tract or fistula after RoCT in vital teeth.
Instrumentation method
As noted above, all five studies used mechanical NiTi instrumentation; none used hand instrumentation (Analysis 2.5).
Discussion
Summary of main results
This review included 47 studies with 5805 participants undergoing RoCT in a single visit or multiple visits. Compared to the last version of the review (2016), we applied minor changes in inclusion criteria, selecting only trials that performed endodontic treatment according to the current standard of care (rubber dam isolation and irrigation with sodium hypochlorite). This resulted in the exclusion of five previously included studies. We included 27 new studies, suggesting worldwide continued interest in researching this topic.
The long‐term retention of the tooth is the ultimate goal of RoCT, but unfortunately, this outcome was rarely investigated. Only two of our 47 included studies reported data on dental extraction and both found no difference between the two approaches. The evidence for the effect of single‐visit versus multiple‐visit treatment on tooth extraction is very uncertain because results are based on only two studies, one of them judged at high risk of bias, and the 95% CI of the RR was very wide.
Another long‐term indicator of the success of RoCT is the absence of periapical radiolucencies in intraoral radiological evaluation. Although some lesions take a long time to resolve and small periapical space enlargements that remain stable over years probably should not be considered a pathological finding, the presence of a radiolucency one year after treatment could indicate the persistence or the development of an endodontic disease, and, therefore, treatment failure. It should be stated that the healing rate established by radiographic interpretation may be biased by human visual perception. However, we found no difference in terms of one‐year radiological healing between people treated in a single visit when compared with those undergoing a multiple‐visit approach. The certainty of evidence for this outcome was downgraded to moderate because it was based on studies that were mostly at high or unclear risk of bias.
The most frequent short‐term complication of RoCT is pain. Pain perception is highly subjective and modulated by multiple physical and psychological factors, and the measurement of pain is fraught with opportunities for error. The level of discomfort must be rated in categories selected in advance and accurately described (e.g. slight pain: the tooth involved was slightly painful for a time, regardless of duration, but no need existed to take analgesics). From the results obtained in this review, there was very low‐ to low‐certainty evidence that the incidence of postobturation pain (evaluated at different times and using both dichotomous and continuous data) was no different in single‐ and multiple‐visit RoCT, although post‐treatment pain within one week (calculated from the single‐visit treatment and from the first session of multiple‐visit treatment) might be less likely to be experienced by people undergoing multiple‐visit RoCT (moderate‐certainty evidence). It is possible that in the single‐visit approach, the longer working time and the obturation‐associated trauma to the periapical tissues cause a more severe acute inflammatory response. The results for pain are indirectly confirmed by data on analgesic use, which was no different between approaches (very low‐certainty evidence), contrary to the results of the last version of our review (Manfredi 2016), in which people treated in a single visit were significantly more likely to use analgesics. The difference was due to the different sets of studies being combined (only three of six were shared with the previous version) and to the exclusion of the study that had the greatest weight in the previous analysis (Soltanoff 1978).
Other less‐frequent complications of RoCT are post‐treatment swelling or the presence of a fistula. The former is not necessarily synonymous with endodontic failure, while the latter is. From the data available, the evidence for the effect of single‐visit versus multiple‐visit treatment on these two outcomes is very uncertain.
When data were available, we performed subgroup analysis for vital teeth/necrotic teeth and hand/mechanical instrumentation. Subgroup analysis found no differences between single‐visit versus multiple‐visit RoCT for our outcomes other than post‐treatment pain within one week, which was higher in single‐visit groups for vital teeth and when instrumentation was mechanical. In necrotic teeth, post‐treatment pain within one week was no different in the single‐ and multiple‐visit approaches. The pretreatment pain conditions of the analysed necrotic teeth (all asymptomatic in Mulhern 1982 and mostly asymptomatic in Abdurrahman 2019) could explain this discrepancy as a higher proportion of symptomatic teeth were treated in the vital teeth analysis.
The results of the current update suggested that the effectiveness of single‐ and multiple‐visit RoCT does not seem to be substantially different. Most short‐ and long‐term complications do not seem to be different in terms of frequency and intensity, although people undergoing single‐visit RoCT may be more likely to experience pain in the first week.
Overall completeness and applicability of evidence
The available evidence is from a wide range of countries and is applicable to healthy people over 10 years of age. Identified trials did not include people with depressed immune systems, people with other illnesses or elderly people. The results of this review may or may not be generalisable to these groups, which would be expected to have different rates of short‐ and long‐term endodontic success.
Most trials were conducted in public practices (hospitals, university or military clinics) and only two trials were performed in private practice. This may influence the generalisability of our results, with particular regard to the number of operators involved in the RoCT or their clinical skill, as those in the included studies varied from expert endodontists working in referral centres to postgraduate students. Whether results would be similar for general dental practitioners is unknown.
Quality of the evidence
On the basis of the criteria used in the critical appraisal of the studies, only 10/47 included studies resulted in an overall low risk of bias. Seven of these 10 studies were new and added in the current update of the revision. This suggests an improvement over time in study design and data reporting.
We assessed the evidence using GRADE (Atkins 2004), and judged the certainty of evidence on tooth extraction due to endodontic problems, postobturation pain at one week, swelling or flare up, analgesic use and presence of sinus track or fistula as very low; the certainty of evidence for pain in the immediate postobturation period as low, and the certainty of evidence for radiological failure and post‐treatment pain (within one week) as moderate (Table 1).
Potential biases in the review process
We have taken steps to minimise the bias in every phase of the review. Nevertheless, although we searched several databases and trial registries with no language limitations, we included 10 studies found by manual searching and not indexed in the searched databases (Gill 2016; Gui 2017; Jethi 2021; Keskin 2015; Markan 2021; Pragya 2016; Qi 2011; Rana 2019; Tarale 2013; Wang 2016). Surprisingly, we found several Chinese trials investigating single‐ versus multiple‐visit RoCT not recorded in the consulted databases. After a preliminary screening, we selected 35 of these trials for full‐text evaluation. Three studies were finally included (Gui 2017; Gui 2017; Wang 2016). The lack of inclusion of Chinese databases in the search strategy could represent a potential source of bias, only partially compensated by manual search. Future review updates should consider including Chinese databases in the search strategy (Mergoni 2021). We tried to contact the study authors to request missing data by e‐mails. We detected no publication bias on the basis of the funnel plots analysis (Figure 6; Figure 7; Figure 8).
6.
Funnel plot of comparison: 2 Signs, outcome: 2.3 Radiological failure.
7.
Funnel plot – pain (continuous) in the immediate postobturation period (until 72 hours postobturation).
8.
Funnel plot – pain (dichotomous) in the immediate postobturation period (until 72 hours postobturation)
In terms of assessing the risk of bias, this was particularly difficult for missing outcome data. To ease this judgement and have consistency across studies, we judged that less than 15% missing data did not constitute a high risk of bias, although acknowledge this is somewhat arbitrary.
When pain was recorded as ordinal scale variable (generally 'no pain', 'mild pain', 'moderate pain' and 'severe pain'), we dichotomised the data into 'no pain' and 'pain', pooling the categories 'mild', 'moderate' and 'severe'. We do not know the impact of a different dichotomisation, for example, pooling 'no pain' and 'mild pain' versus 'moderate' and 'severe pain'.
Agreements and disagreements with other studies or reviews
Comparing the results from other systematic reviews is difficult because of differences in inclusion and exclusion criteria, search strategies, outcomes, data extraction methods, or result synthesis and statistical analysis approaches.
Su 2011 and Zhang 2015 analysed the differences between single and multiple visits for endodontic treatment in teeth with infected root canals only. The results of the two reviews did not differ significantly from those of our subgroup analysis in necrotic teeth. Su 2011 considered several outcomes. When analysing short‐term postobturation pain, there was a benefit for participants undergoing single‐visit RoCT. This inconsistency with our results could be explained by the different sets of studies being combined. The two reviews considered studies published in different time intervals and applied different inclusion and exclusion criteria. Su 2011 only considered three studies for this outcome, while in our review, there were six and, among them, only two studies were shared with Su 2011. In addition, the data from one of the shared studies were slightly different, probably because of an error in the extraction process (Mulhern 1982).
Wong 2014 concluded that the studies reported in the literature showed that neither single‐visit endodontic treatment nor multiple‐visit treatment could guarantee the absence of postoperative pain. It found that neither single‐visit endodontic treatment nor multiple‐visit treatment had superior results in terms of healing or success rate, which our review also found.
Almeida 2017 found no difference in periapical repair and microbiological control after single‐ versus multiple‐visit endodontic therapy of non‐vital teeth, but less postobturation pain in single‐visit groups. A possible explanation of the discrepancy with the results of the current review is that different trials were included and that, in Almeida 2017, when pain was recorded multiple times in the interval 0 to 72 hours, the authors considered the value of pain at 48 hours. In our review, when the outcomes were recorded multiple times in the time range of interest, we chose the highest value.
Schwendicke 2017 carried out a systematic review applying inclusion criteria similar to those used in the current review. The analysis of the 29 included studies led the authors to conclude that the risk of pain was no different in single‐visit versus multiple‐visit treatment. In the same review, the risk of flare‐up was higher after single‐visit treatment. The discrepancy with the results of the current review could be due to the different definitions of flare‐up: we considered flare‐up as swelling, while Schwendicke 2017 considered flare‐up as a short‐term symptom (less than one year, usually directly after initiation or conclusion of RoCT) that led or can be assumed to have led to further intervention.
Izadpanah 2021, considering only English language studies, found that the risk of postoperative pain in single‐visit RoCT was higher than that in multiple‐visit RoCT.
Nunes 2021 found that both single‐ and multiple‐visit retreatments can be considered adequate, with a similar occurrence of postoperative pain. In Vishwanathaiah 2021, the inclusion criteria stated that only vital teeth would be considered, but we observed that trials on non‐vital teeth had also been included. The subsequent meta‐analysis did not reveal any difference in the incidence or the intensity of the postendodontic flare‐up between the single‐ and multiple‐visit RoCT groups. The definition of flare‐up was different from the current review, referring to intense pain or swelling (or both) of the facial soft tissues and the oral mucosa.
Moreira 2017 published an overview of systematic reviews on endodontic treatment in single and multiple visits, considering also the first version of this review (Figini 2007). The study concluded that single and multiple visits showed similar repair or success rates regardless of the pulp/periapex preoperative conditions and that the apical periodontitis subgroup showed a slightly positive trend towards a decreased incidence of postoperative complications and higher effectiveness and efficiency for a single session. The latter result was not confirmed by the current review.
Authors' conclusions
Implications for practice.
There is no evidence to suggest that one regimen (single visit or multiple visits) is more effective than the other for root canal treatment. Neither can prevent pain and other complications in the 12‐month postoperative period. Based on the available evidence, it seems likely that the benefit of a single‐visit treatment, in terms of time and convenience for both patient and dentist, may have the cost of a slightly higher incidence of postoperative pain.
Implications for research.
Based on our review, root canal treatment in single session and in multiple sessions proved to be no different in terms of cure rate and long‐term complications. Treatment in a single visit may be associated with a slightly higher likelihood of postoperative pain. To support the choice of the clinician, it would be useful to investigate the participant's preference with respect to the two treatment modalities, for example using patient‐related outcome measures and assessing the economic impact.
In addition, future trials should consider the effect of prognostic factors, such as demographics, size of the lesion, preoperative sinus tract and systemic diseases, to test the superiority of the multiple‐visit approach in selected patients with a higher risk of endodontic treatment failure.
At the moment, the routine use of more sensitive radiological tests such as cone‐beam computed tomography for postendodontic treatment evaluation is precluded because of the higher radiant exposure compared to traditional radiology. If it is possible to reduce the radiant burden in the future, the use of cone‐beam computed tomography for the evaluation of the healing rate after single‐ or multiple‐visit treatment could lead to different results compared to those obtained with traditional radiology.
What's new
| Date | Event | Description |
|---|---|---|
| 5 January 2023 | Amended | Minor edit (typographical error ‐ missing closed bracket added in Plain Language Summary) |
History
Protocol first published: Issue 2, 2005 Review first published: Issue 4, 2007
| Date | Event | Description |
|---|---|---|
| 13 December 2022 | New citation required but conclusions have not changed | Our substantive conclusions have not changed. Based on available evidence, the benefit of a single‐visit treatment, in terms of time and convenience, for both patient and dentist, may have the cost of a higher frequency of postoperative pain. |
| 13 December 2022 | New search has been performed | Search updated: 27 new studies added making a total of 47 studies. Due to modifications of eligible criteria, we excluded 5 studies from the previous version of the review. |
| 31 July 2008 | Amended | Converted to new review format. |
Notes
This is the second update of a review that was originally published in 2007 and first updated in 2016 (Figini 2007; Manfredi 2016). The original protocol for the review was published in 2005 (Gagliani 2005).
Acknowledgements
The review authors thank Cochrane Oral Health for their continuous support (in particular, Laura MacDonald, Tanya Walsh, Anne‐Marie Glenny, Helen Worthington, Anne Littlewood and Trevor Johnson), all the researchers of included studies who have provided some of the data useful in the review, our peer reviewers Emma Beecroft and Peter Carrotte, and copy editor Anne Lawson, Central Production Service, Cochrane.
Appendices
Appendix 1. Cochrane Oral Health's Trials Register search strategy
Cochrane Oral Health's Trials Register is available via the Cochrane Register of Studies. For information on how the register is compiled, see oralhealth.cochrane.org/trials.
From July 2013, updated searches of Cochrane Oral Health's Trials Register were undertaken using the Cochrane Register of Studies and the search strategy below:
#1 ((endodontic* OR "root canal" OR pulp* OR "root fill*"):ti,ab) AND (INREGISTER) #2 (("single visit*" OR single‐visit* OR "single appoint*" OR single‐appoint* OR "single session*" OR single‐session* OR "multiple visit*" OR multiple‐visit* OR "multiple appoint*" OR multiple‐appoint* OR "multiple session*" OR multiple‐session* OR "first visit*" OR first‐visit* OR "1st visit*" OR 1st‐visit* OR "one visit" OR one‐visit OR "first appointment" OR "one appointment" OR one‐appointment OR "first session*" OR "one session" OR one‐session OR "second visit*" OR "2nd visit*" OR "two visit*" OR two‐visit* OR "two appointment*" OR two‐appointment* OR "two session*" OR "two‐session*" OR "third visit*" OR third‐visit OR "three visit*" OR three‐visit* OR "third apointment*" OR third‐appointment* OR "three appointment*" OR three‐appointment* OR "three session*" OR three‐session* OR "single and multiple visit*" OR "one and two visit*"):ti,ab) AND (INREGISTER) #3 (#1 and #2) AND (INREGISTER)
Previous searches of Cochrane Oral Health's Trials Register were undertaken using the Procite software and the search strategy below:
((endodontic* OR "root canal" OR pulp* OR "root fill*") AND ("single visit*" OR single‐visit* OR "single appoint*" OR single‐appoint* OR "single session*" OR single‐session* OR "multiple visit*" OR multiple‐visit* OR "multiple appoint*" OR multiple‐appoint* OR "multiple session*" OR multiple‐session* OR "first visit*" OR first‐visit* OR "1st visit*" OR 1st‐visit* OR "one visit" OR one‐visit OR "first appointment" OR "one appointment" OR one‐appointment OR "first session*" OR "one session" OR one‐session OR "second visit*" OR "2nd visit*" OR "two visit*" OR two‐visit* OR "two appointment*" OR two‐appointment* OR "two session*" OR "two‐session*" OR "third visit*" OR third‐visit OR "three visit*" OR three‐visit* OR "third apointment*" OR third‐appointment* OR "three appointment*" OR three‐appointment* OR "three session*" OR three‐session* OR "single and multiple visit*" OR "one and two visit*"))
Appendix 2. Cochrane Central Register of Controlled Trials (CENTRAL) search strategy
#1 MeSH descriptor Endodontics explode all trees #2 (endodontic* in All Text or pulpectom* in All Text or pulpotom* in All Text) #3 "root canal" in All Text #4 ( (pulp in All Text near/4 cap* in All Text) or (pulp in All Text near/4 devital* in All Text) ) #5 (#1 or #2 or #3 or #4) #6 (single next visit* in All Text or single next appointment* in All Text or single next session* in All Text) #7 (multi* next visit* in All Text or multi* next appointment* in All Text or multi* next session* in All Text) #8 (first next visit* in All Text or first next appointment* in All Text or first next session* in All Text or second next visit* in All Text or second next appointment* in All Text or second next session* in All Text or third next visit* in All Text or third next appointment* in All Text or third next session* in All Text) #9 (1st next visit* in All Text or 1st next appointment* in All Text or 1st next session* in All Text or 2nd next visit* in All Text or 2nd next appointment* in All Text or 2nd next session* in All Text or 3rd next visit* in All Text or 3rd next appointment* in All Text or 3rd next session* in All Text) #10 (one next visit* in All Text or one next appointment* in All Text or one next session* in All Text or two next visit* in All Text or two next appointment* in All Text or two next session* in All Text or three next visit* in All Text or three next appointment* in All Text or three next session* in All Text) #11 (#6 or #7 or #8 or #9 or #10) #12 (#5 and #11)
Appendix 3. MEDLINE Ovid search strategy
1 ENDODONTICS/ 2. exp ROOT CANAL THERAPY/ 3. dental pulp capping/ or pulpectomy/ or pulpotomy/ 4. (endodontic$ or pulpectom$ or pulpotom$) 5. (root canal adj (therapy or treat$)) 6. ((pulp adj3 cap$) or (pulp$ adj3 devitali$)) 7. or/1‐6 8. (single adj (visit$ or appointment$ or session$)) 9. (multi$ adj (visit$ or appointment$ or session$)) 10. ((first or second or third) adj (visit$ or appointment$ or session$)) 11. ((1st or 2nd or 3rd) adj (visit$ or appointment$ or session$)) 12. ((one or two or three) adj (appointment$ or visit$ or session$)) 13 or/8‐12 14. 7 and 13
The above subject search was linked with the highly sensitive search strategy designed by Cochrane for identifying randomised controlled trials and controlled clinical trials in MEDLINE (as described in Lefebvre 2022, box 3c).
1. randomized controlled trial.pt. 2. controlled clinical trial.pt. 3. randomized.ab. 4. placebo.ab. 5. drug therapy.fs. 6. randomly.ab. 7. trial.ab. 8. groups.ab. 9. or/1‐8 10. exp animals/ not humans.sh. 11. 9 not 10
Appendix 4. Embase Ovid search strategy
1 ENDODONTICS/ 2. exp ROOT CANAL THERAPY/ 3. dental pulp capping/ or pulpectomy/ or pulpotomy/ 4. (endodontic$ or pulpectom$ or pulpotom$) 5. (root canal adj (therapy or treat$)) 6. ((pulp adj3 cap$) or (pulp$ adj3 devitali$)) 7. or/1‐6 8. (single adj (visit$ or appointment$ or session$)) 9. (multi$ adj (visit$ or appointment$ or session$)) 10. ((first or second or third) adj (visit$ or appointment$ or session$)) 11. ((1st or 2nd or 3rd) adj (visit$ or appointment$ or session$)) 12. ((one or two or three) adj (appointment$ or visit$ or session$) 13 or/8‐12 14. 7 and 13
The above subject search was linked with the highly sensitive search strategy designed by Cochrane for identifying randomised controlled trials and controlled clinical trials in Embase (as described in Lefebvre 2022, box 3e).
Randomized controlled trial/
Controlled clinical study/
random$.ti,ab.
randomization/
intermethod comparison/
placebo.ti,ab.
(compare or compared or comparison).ti.
((evaluated or evaluate or evaluating or assessed or assess) and (compare or compared or comparing or comparison)).ab.
(open adj label).ti,ab.
((double or single or doubly or singly) adj (blind or blinded or blindly)).ti,ab.
double blind procedure/
parallel group$1.ti,ab.
(crossover or cross over).ti,ab.
((assign$ or match or matched or allocation) adj5 (alternate or group$1 or intervention$1 or patient$1 or subject$1 or participant$1)).ti,ab.
(assigned or allocated).ti,ab.
(controlled adj7 (study or design or trial)).ti,ab.
(volunteer or volunteers).ti,ab.
human experiment/
trial.ti.
or/1‐19
random$ adj sampl$ adj7 ("cross section$" or questionnaire$1 or survey$ or database$1)).ti,ab. not (comparative study/ or controlled study/ or randomi?ed controlled.ti,ab. or randomly assigned.ti,ab.)
Cross‐sectional study/ not (randomized controlled trial/ or controlled clinical study/ or controlled study/ or randomi?ed controlled.ti,ab. or control group$1.ti,ab.)
(((case adj control$) and random$) not randomi?ed controlled).ti,ab.
(Systematic review not (trial or study)).ti.
(nonrandom$ not random$).ti,ab.
"Random field$".ti,ab.
(random cluster adj3 sampl$).ti,ab.
(review.ab. and review.pt.) not trial.ti.
"we searched".ab. and (review.ti. or review.pt.)
"update review".ab.
(databases adj4 searched).ab.
(rat or rats or mouse or mice or swine or porcine or murine or sheep or lambs or pigs or piglets or rabbit or rabbits or cat or cats or dog or dogs or cattle or bovine or monkey or monkeys or trout or marmoset$1).ti. and animal experiment/
Animal experiment/ not (human experiment/ or human/)
or/21‐33
20 not 34
Appendix 5. US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform search strategy
endodontic and visit endodontic and appointment endodontic and session
Data and analyses
Comparison 1. Single versus multiple visits for endodontic treatment of permanent teeth – primary outcomes.
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
|---|---|---|---|---|
| 1.1 Extraction due to endodontic problems | 2 | 402 | Risk Ratio (M‐H, Random, 95% CI) | 0.46 [0.09, 2.50] |
| 1.2 Radiological failure | 13 | Risk Ratio (IV, Random, 95% CI) | Subtotals only | |
| 1.2.1 Radiological failure | 13 | 1505 | Risk Ratio (IV, Random, 95% CI) | 0.93 [0.81, 1.07] |
| 1.2.2 Radiological failure in necrotic teeth | 10 | 924 | Risk Ratio (IV, Random, 95% CI) | 0.83 [0.61, 1.14] |
| 1.2.3 Radiological failure in vital teeth | 1 | 184 | Risk Ratio (IV, Random, 95% CI) | 1.19 [0.40, 3.55] |
| 1.2.4 Radiological failure – hand instrumentation | 6 | 475 | Risk Ratio (IV, Random, 95% CI) | 0.89 [0.58, 1.38] |
| 1.2.5 Radiological failure – NiTi mechanical instrumentation | 6 | 928 | Risk Ratio (IV, Random, 95% CI) | 0.93 [0.71, 1.23] |
Comparison 2. Single versus multiple visits for endodontic treatment of permanent teeth – secondary outcomes.
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
|---|---|---|---|---|
| 2.1 Pain (dichotomous) | 18 | Risk Ratio (M‐H, Random, 95% CI) | Subtotals only | |
| 2.1.1 Post‐treatment pain (within 1 week) | 5 | 638 | Risk Ratio (M‐H, Random, 95% CI) | 1.55 [1.14, 2.09] |
| 2.1.2 Post‐treatment pain (within 1 week) in necrotic teeth | 2 | 104 | Risk Ratio (M‐H, Random, 95% CI) | 1.01 [0.55, 1.84] |
| 2.1.3 Post‐treatment pain (within 1 week) in vital teeth | 2 | 316 | Risk Ratio (M‐H, Random, 95% CI) | 2.16 [1.39, 3.36] |
| 2.1.4 Post‐treatment pain (within 1 week) – hand instrumentation | 3 | 360 | Risk Ratio (M‐H, Random, 95% CI) | 1.23 [0.77, 1.98] |
| 2.1.5 Post‐treatment pain (within 1 week) – NiTi mechanical instrumentation | 2 | 278 | Risk Ratio (M‐H, Random, 95% CI) | 1.80 [1.10, 2.92] |
| 2.1.6 Pain in the immediate postobturation period (until 72 hours postobturation) | 12 | 1329 | Risk Ratio (M‐H, Random, 95% CI) | 0.97 [0.81, 1.16] |
| 2.1.7 Pain in the immediate postobturation period (until 72 hours postobturation) in necrotic teeth | 6 | 569 | Risk Ratio (M‐H, Random, 95% CI) | 0.97 [0.81, 1.16] |
| 2.1.8 Pain in the immediate postobturation period (until 72 hours postobturation) in vital teeth | 4 | 402 | Risk Ratio (M‐H, Random, 95% CI) | 1.33 [0.94, 1.88] |
| 2.1.9 Pain in the immediate postobturation period (until 72 hours postobturation) – hand instrumentation | 7 | 709 | Risk Ratio (M‐H, Random, 95% CI) | 0.81 [0.58, 1.12] |
| 2.1.10 Pain in the immediate postobturation period (until 72 hours postobturation) – NiTi mechanical instrumentation | 5 | 467 | Risk Ratio (M‐H, Random, 95% CI) | 1.15 [0.81, 1.62] |
| 2.1.11 Postobturation pain at 1 week | 9 | 1139 | Risk Ratio (M‐H, Random, 95% CI) | 1.05 [0.67, 1.67] |
| 2.1.12 Postobturation pain at 1 week in necrotic teeth | 4 | 445 | Risk Ratio (M‐H, Random, 95% CI) | 1.52 [0.24, 9.41] |
| 2.1.13 Postobturation pain at 1 week in vital teeth | 3 | 249 | Risk Ratio (M‐H, Random, 95% CI) | 1.52 [0.90, 2.55] |
| 2.1.14 Postobturation pain at 1 week – hand instrumentation | 4 | 472 | Risk Ratio (M‐H, Random, 95% CI) | 0.82 [0.47, 1.42] |
| 2.1.15 Postobturation pain at 1 week – NiTi mechanical instrumentation | 5 | 667 | Risk Ratio (M‐H, Random, 95% CI) | 1.23 [0.63, 2.38] |
| 2.1.16 Postobturation pain at 2 weeks | 2 | 288 | Risk Ratio (M‐H, Random, 95% CI) | 0.56 [0.07, 4.69] |
| 2.1.17 Postobturation pain at 1 month | 1 | 60 | Risk Ratio (M‐H, Random, 95% CI) | Not estimable |
| 2.1.18 Postobturation pain at 1 month in vital teeth | 1 | 60 | Risk Ratio (M‐H, Random, 95% CI) | Not estimable |
| 2.1.19 Postobturation pain after 12 months or more | 2 | 246 | Risk Ratio (M‐H, Random, 95% CI) | 0.88 [0.06, 13.90] |
| 2.2 Pain (continuous) | 12 | Mean Difference (IV, Random, 95% CI) | Subtotals only | |
| 2.2.1 Pain in the immediate postobturation period (until 72 hours postobturation) | 12 | 1258 | Mean Difference (IV, Random, 95% CI) | 0.26 [‐4.76, 5.29] |
| 2.2.2 Pain in the immediate postobturation period (until 72 hours postobturation) in necrotic teeth | 6 | 343 | Mean Difference (IV, Random, 95% CI) | ‐0.07 [‐0.56, 0.42] |
| 2.2.3 Pain in the immediate postobturation period (until 72 hours postobturation) in vital teeth | 2 | 130 | Mean Difference (IV, Random, 95% CI) | 0.69 [‐0.78, 2.17] |
| 2.2.6 Postobturation pain at 1 week | 4 | 368 | Mean Difference (IV, Random, 95% CI) | Not estimable |
| 2.2.7 Postobturation pain at 1 week in necrotic teeth | 2 | 100 | Mean Difference (IV, Random, 95% CI) | Not estimable |
| 2.2.8 Postobturation pain at 1 week in vital teeth | 1 | 100 | Mean Difference (IV, Random, 95% CI) | Not estimable |
| 2.3 Swelling or flare‐up | 6 | Risk Ratio (M‐H, Random, 95% CI) | Subtotals only | |
| 2.3.1 Swelling or flare‐up | 6 | 605 | Risk Ratio (M‐H, Random, 95% CI) | 0.56 [0.16, 1.92] |
| 2.3.2 Swelling or flare‐up in necrotic teeth | 2 | 142 | Risk Ratio (M‐H, Random, 95% CI) | 5.00 [0.25, 99.95] |
| 2.3.3 Swelling or flare‐up in vital teeth | 2 | 209 | Risk Ratio (M‐H, Random, 95% CI) | 0.53 [0.09, 3.00] |
| 2.3.4 Swelling or flare‐up – hand instrumentation | 2 | 142 | Risk Ratio (M‐H, Random, 95% CI) | 5.00 [0.25, 99.95] |
| 2.3.5 Swelling or flare‐up – mechanical NiTi instrumentation | 4 | 463 | Risk Ratio (M‐H, Random, 95% CI) | 0.36 [0.09, 1.38] |
| 2.4 Analgesic use | 6 | Risk Ratio (M‐H, Random, 95% CI) | Subtotals only | |
| 2.4.1 Analgesic use | 6 | 540 | Risk Ratio (M‐H, Random, 95% CI) | 1.25 [0.75, 2.09] |
| 2.4.2 Analgesic use in necrotic teeth | 2 | 104 | Risk Ratio (M‐H, Random, 95% CI) | 1.29 [0.52, 3.19] |
| 2.4.3 Analgesic use in vital teeth | 2 | 149 | Risk Ratio (M‐H, Random, 95% CI) | 0.93 [0.71, 1.23] |
| 2.4.4 Analgesic use – hand instrumentation | 2 | 104 | Risk Ratio (M‐H, Random, 95% CI) | 1.29 [0.52, 3.19] |
| 2.4.5 Analgesic use – mechanical NiTi instrumentation | 4 | 436 | Risk Ratio (M‐H, Random, 95% CI) | 1.29 [0.57, 2.93] |
| 2.5 Presence sinus tract or fistula | 5 | Risk Ratio (M‐H, Random, 95% CI) | Subtotals only | |
| 2.5.1 Presence of sinus tract or fistula | 5 | 650 | Risk Ratio (M‐H, Random, 95% CI) | 1.00 [0.24, 4.28] |
| 2.5.2 Presence of sinus tract of fistula in necrotic teeth | 4 | 468 | Risk Ratio (M‐H, Random, 95% CI) | 1.35 [0.26, 6.84] |
| 2.5.3 Presence of sinus tract of fistula – mechanical NiTi instrumentation | 5 | 650 | Risk Ratio (M‐H, Random, 95% CI) | 1.00 [0.24, 4.28] |
Characteristics of studies
Characteristics of included studies [ordered by study ID]
Abdurrahman 2019.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Egypt Number of centres: 1, Department of Endodontics, Cairo University, Cairo, Egypt Setting: university clinic Recruitment period: November 2016 to February 2018 Funding source: no grants were involved |
|
| Participants | Number of participants: 44 Number of teeth: 44 Demographics (e.g. sex, age, ethnic group): 35 F, 9 M Pulp status: necrotic teeth Inclusion criteria: medically healthy people aged 16–55 years. All had a necrotic tooth with a periapical lesion confirmed radiographically (minimum size 2 × 2 mm) Exclusion criteria: teeth previously accessed or endodontically treated; vital or necrotic teeth without periapical lesion; allergy to metronidazole, ciprofloxacin or doxycycline or those with significant medical conditions; people who took analgesia before treatment up to 12 hours previously and pregnant women. Diagnostic criteria: teeth were tested with an electric pulp test to determine pulp sensitivity. X‐rays were taken to detect periapical lesions. Randomisation: participants were divided randomly into 2 groups with a table of random numbers from 1 to 44. Group 1: randomised 22, analysed 22 Group 2: randomised 22, analysed 22 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2) with triple antibiotic paste interappointment dressing. After ≥ 7 days, the interappointment dressing was removed by H‐files and 2.6% NaOCl and 17% EDTA irrigation followed by saline final wash. Local anaesthesia was administered if needed. 1 operator. Use of magnification not reported. Isolation with rubber dam. Root canals was instrumented by hybrid technique (Gates‐Glidden drills, K‐files, H‐files). Working length measured using EAL and radiograph, where it was set 1 mm away from the radiographic apex. Irrigation using 2.6% NaOCl. Lubrication using EDTA gel. Final irrigation with 5 mL 17% EDTA solution. Final wash using saline. Master cone‐fit radiograph was taken to ensure proper length and preparation. The canals were dried with paper points. At time of obturation, cold lateral condensation technique used with resin sealer. After obturation, glass ionomer was placed to seal the access cavity. |
|
| Outcomes |
Postoperative pain at 24, 48 and 72 hours and 1 week after instrumentation (first visit of group 2 and the single visit of group 1); recorded by participants using NRS in a pain diary Pain intensity categorised into: 0 = none; 1–3 = mild; 4–6 = moderate; 7–10 = severe.
Incidence of analgesic intake and number of tablets (ibuprofen 400 mg) consumed in case of presence of moderate or severe postoperative pain |
|
| Notes | Pain recorded after canal instrumentation and not after canal obturation. In group 2, pain recorded in interappointment period of the multiple‐visit RoCT; such data were not included in the meta‐analysis as they could not be compared with a similar outcome of the single‐visit approach. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "participants were divided randomly into two groups with a table of random numbers from 1 to 44 generated by SMA using a freely available computer program with n=22/group". |
| Allocation concealment (selection bias) | Low risk | Quote: "the allocation table was kept with an investigator not involved with participant enrollment. Numbers from 1 to 44 were written on 44 pieces of paper folded eight‐times. Each paper was placed separately in a closed opaque envelope". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 44/44 participants enrolled (100%) were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Akbar 2013.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Pakistan Number of centres: 1, Department of Conservative Dentistry, Punjab Dental Hospital, Lahore Setting: hospital dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 100 Number of teeth: 100 Demographics (e.g. sex, age, ethnic group): 49 F, 51 M; aged 12–40 years Inclusion criteria: 1 asymptomatic molar tooth with periapical radiolucency Exclusion criteria: not reported Diagnostic criteria for pulpal or periapical disease: periapical Rx of the involved tooth and participant's history Group 1: 50 randomised, 50 analysed Group 2: 50 randomised, 50 analysed |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; not reported how many days after the first the second visit was performed, root canal medication with CH) Number of operators not reported. Rubber dam isolation. Use of magnification loupes not reported. Canal shaping: step‐back technique by K files and gates Glidden‐drills. Canal irrigation: 2 mL 2.5% NaOCl. Working length determined by Rx. Obturation with gutta‐percha cones and a ZOE sealer in lateral condensation technique |
|
| Outcomes |
Measured after obturation and daily for 7 days and defined as moderate‐to‐severe pain, or moderate‐to‐severe swelling that began 12–48 hours after treatment with duration ≥ 48 hours. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "the patients were randomly assigned into two groups". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100/100 (100%) participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: important outcomes and adverse effects reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Al‐Negrish 2006.
| Study characteristics | ||
| Methods | Study design: quasi‐randomised parallel‐group clinical trial Country: Jordan Number of centres: 1, Prince Rashed Bin Al‐Hassan Hospital Setting: hospital dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 120 Number of teeth: 120 Demographics (e.g. sex, age, ethnic group): 66 F, 54 M; aged 15–45 years Inclusion criteria: 1 asymptomatic necrotic central incisor. Exclusion criteria: any evidence of periapical radiolucent lesion, teeth tender to touch, with intracanal calcification or incompletely formed apices, retreatments, teeth with pulpal sensitivity and vitality Diagnostic criteria for pulpal or periapical disease: Rx signs, pulp testing, presence or absence of haemorrhage upon access opening Group 1: 60 quasi‐randomised; 54 analysed Group 2: 60 quasi‐randomised; 58 analysed |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 7 days after first, root canal medication with CH paste with a dry sterile cotton pledget and temporary filling restoration for 7 days) Single operator. Rubber dam isolation. Use of magnification loupes not reported. Canal shaping: step‐back technique with conventional K files and gates. Irrigation: 2.5% NaOCl. Working length determined by Rx. Obturation with gutta‐percha and a ZOE sealer in lateral condensation |
|
| Outcomes |
Pain after 2‐day postobturation period and after 7‐day postobturation period was reported with a 4‐grade scale: 1 = no pain, 2 = slight pain, 3 = moderate pain, 4 = severe pain. In the present review, the scale was dichotomised: no pain versus pain (slight, moderate or severe).
Proportion of participants experiencing moderate‐to‐severe pain evaluated after 2 and 7 days (see Table 3) |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Comment: quasi‐random method. |
| Allocation concealment (selection bias) | High risk | Comment: no allocation concealment was possible as participants were alternately assigned to treatments. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 112/120 participants (93.3% of those who entered the study) were included in the final analysis. 8 participants (6 F and 2 M, 6 from group 1 and 2 from group 2) were excluded from the analysis of the results as they failed to attend postoperative visits. |
| Selective reporting (reporting bias) | Low risk | Comment: important outcomes and adverse effects reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Alomaym 2019.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: Saudi Arabia Number of centres: 1, King Fahad Specialist hospital, Al‑Qassim, Saudi Arabia Setting: hospital dental clinic Recruitment period: July 2017 to May 2018 Funding source: not reported |
|
| Participants | Number of participants: 400 Number of teeth: 400 Demographics (e.g. sex, age, ethnic group): sex distribution was reported only for analysed participants Pulp status: both necrotic and vital teeth Inclusion criteria: aged > 18 years; requiring endodontic treatment; teeth with completely formed foramina and no calcified canals Exclusion criteria: pregnant, receiving antibiotics or corticosteroids, immunocompromised and people with complicating systemic disease, aged < 18 years Diagnostic criteria: pulp vitality determined by electric pulp tester Randomisation: computer random draw method Group 1: randomised 200 participants, analysed 195 (132 M, 63 F) Group 2: randomised 200 participants, analysed 195 (103 M, 92 F) |
|
| Interventions | Group 1: single visit (coronal obturation with Cavit) Group 2: multiple visits (2). Intracanal medication with CH (even though in the discussion the study authors stated "In multi‑visit group, we did not place any intracanal medicament"). Temporarily obturation with sterile cotton pellet and Cavit. Canal obturation performed after 1 week. Local anaesthesia administered. 1 operator. Use of magnification not reported. Isolation of the tooth with rubber dam. Root canals were instrumented by hand files and engine‐driven rotary NiTi files. No information on working length measure technique. Irrigation using 2.5% NaOCl. Canals dried with paper points. At time of obturation, cold lateral condensation technique used with Protaper Universal gutta‐percha and epoxy resin sealer. |
|
| Outcomes |
VAS (modified Heft Parkera) used to measure preoperative pain and postobturation pain at 6, 12, 24 and 48 hours' postobturation.
Not reported in the Materials and Methods section of paper, but number of flare‐ups was reported the Results section. |
|
| Notes |
aUnclear if VAS was expressed on a scale of 100 mm or 170 mm thus data were not included. Contacted authors through e‐mail but received no reply. Data about flare‐up were not included since study authors did not define flare‐up. Review authors emailed trial authors to ask whether the intracanal medication was used but received no reply. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Patients were randomly grouped into two categories (S [single] and M [multiple]), 200 each, by computer random draw method". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 390/400 (97.5%) participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Chhabra 2017.
| Study characteristics | ||
| Methods | Study design: randomised 4‐arm parallel‐group clinical trial Country: India Number of centres: 1, Bhojia Dental College and Hospital Setting: university hospital Recruitment period: unspecified Funding source: authors declared there was no financial support. |
|
| Participants | Number of participants: 60 Number of teeth: 60 Demographics (e.g. sex, age, ethnic group): not reported Pulp status: necrotic teeth Inclusion criteria: aged > 18 years, single‐ and multi‐rooted teeth with radiographic evidence of periapical pathology Exclusion criteria: any systemic diseases; pregnant; had been taking antibiotics, non‐steroidal anti‐inflammatory drugs or corticosteroids before time of treatment; needing antibiotic premedication for dental treatment; if tooth had been previously accessed, grossly decayed teeth, teeth with calcified canals, weeping canals and teeth requiring retreatment Diagnostic criteria: clinical examination and preoperative intraoral periapical radiographs Randomisation: method of randomisation not reported Group 1: randomised 30, analysed 30. Subgroup IIA + subgroup IIB Group 2: randomised 30, analysed 30. Subgroup IA + subgroup IB |
|
| Interventions | Group 1: single visit. Subgroup IIA was obturated with CH‐based sealer and subgroup IIB with epoxy resin sealer. Group 2: multiple visit (2 visits, second visit after 7–10 days). CH medicament used into root canal and temporarily restored with ZnO cement. Obturation with CH‐based sealer (subgroup IA) or epoxy resin sealer (subgroup IB). Use of rubber dam isolation, local anaesthesia administered with 2% lignocaine hydrochloride. Number of operator and use of magnification not reported. Glide path made with 10 and 15 K‐files and working length determined with an apex locator and confirmed using radiography. Shaping using NiTi rotary files and irrigation with saline, 3% NaOCl and 2% CHX during and after instrumentation with EDTA gel used as a lubricant. Canals dried with paper points and obturated with gutta‐percha cones and CH‐based or epoxy resin‐based sealer, using lateral compaction technique. Access cavity sealed using direct composite restoration, and immediate postobturation intraoral periapical radiograph taken. |
|
| Outcomes |
|
|
| Notes | No data could be extracted. Radiographic assessment was made too early (6 months). No data on the clinical assessment reported. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 60/60 (100%) participants enrolled were analysed. |
| Selective reporting (reporting bias) | High risk | Comment: data on clinical assessment not reported. |
| Other bias | Low risk | Comment: no other source of bias identified. |
de Castro Rizzi‐Maia 2016.
| Study characteristics | ||
| Methods | Study design: split‐cluster randomised clinical study Country: Brazil Number of centres: 1, Endodontics Clinic of CEUMA University Setting: university clinic Recruitment period: unspecified Funding source: financial support Fundação de Amparo à Pesquisa do Maranhão (FAPEMA) |
|
| Participants | Number of participants: 14 Number of teeth: 28, mature single‐rooted teeth Demographics (e.g. sex, age, ethnic group): aged 18–58 years Pulp status: necrotic teeth Inclusion criteria: radiographically visible AP lesion and no previous RoCT Exclusion criteria: used antibiotics or antimicrobial agents within 6 months prior to study, smokers, pregnant women, people with diabetes, immunosuppressed people, people undergoing radiotherapy, or had severe periodontal disease or periodontal pockets Diagnostic criteria: radiographic examination Randomisation: teeth were randomly assigned to 2 groups (14/group) by simple random sampling (draw). Each participant received both RoCT modalities. Group 1: randomised 14, analysed 13 Group 2: randomised 14, analysed 13 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; medication with CH‐based paste, a cotton pellet and a temporary glass ionomer cement restoration performed between visits, second visit after 14 days) Rubber dam isolation. Use of magnification not reported. 1 operator. Shaping with K files and ProTaper universal alternating irrigation with 5.25% NaOCl and aspiration. Root canal length measurement determined 1 mm short of apex using EAL. At end of instrumentation, canals were filled with EDTA 17% for 3 min and dried with paper points. Obturation: lateral condensation of gutta‐percha and epoxy resin sealer. |
|
| Outcomes |
Presence of defective restorations, fistulas, pain on mastication, 12 months after RoCT
CBCT scans obtained before endodontic treatment and 12 months after treatment. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "The teeth were randomly assigned to two groups by simple random sampling". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "an experienced, blind, calibrated radiologist evaluated the pre‐ and postoperative volumes of the PA lesions". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 1 participant lost to follow‐up. 13/14 participants evaluated. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Dhyani 2022.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: India Number of centres: 1, Armed Forces Medical Services Setting: military dental centre Recruitment period: unspecified Funding source: authors declared no financial support. |
|
| Participants | Number of participants: 60 Number of teeth: 60 Demographics (e.g. sex, age, ethnic group): 36 F, 24 M; mean age 30.6 years Pulp status: vital teeth Inclusion criteria: acute irreversible pulpitis, aged 18–40 years Exclusion criteria: systemic disease, cognitive dysfunction, immunocompromised, retreatment case, pregnant. Teeth with compromised periodontal support, fractures, draining sinuses, tenderness on percussion, unfavourable morphology and radiographic evidence of pulpal calcifications or distorted root anatomy Diagnostic criteria: detailed medical and dental history and clinical examination Randomisation: group allocation and randomisation carried out by designated personnel using manual lottery method. 30 allocation slips in unmarked envelopes were drafted for each group and combined to create the lottery pool. Group 1: randomised 30, analysed 30 Group 2: randomised 30, analysed 30 |
|
| Interventions | Group 1: single visit Group 2: multiple visit (3 visitsa). CH was used as interappointment medicament. First visit: access opening and coronal flaring, followed by closed dressing. An aqueous solution of used as interappointment, intracoronal medicament. Second visit: working length determination and chemomechanical preparation, followed by closed dressing. Third visit: obturation and restoration with light cure composite. Local anaesthesia administered. Number of operators and use of magnification not reported. Use of rubber dam reported. Shaping: rotary nickel titanium files in crown‐down technique. Irrigation with 5.25% NaOCl solution and lubrification with EDTA gel. Working length determination with EAL and confirmed radiographically Obturation carried out with gutta‐percha cones and resin‐based root canal sealer in lateral condensation technique. Postoperative radiographs were taken to evaluate the quality of obturation. Restoration with light cure composite. |
|
| Outcomes |
Pain recorded on a VAS of 0 to 10, where 0 = no pain, 1–3 = mild pain, 4–6 = moderate pain, 7–10 = severe pain. Pain evaluated the day after every visit and after obturation on days 1, 7 and 30.
Flare‐ups classified as a severe uncontrollable amount of interappointment and postoperative pain, not relieved by medication, requiring an unscheduled visit for active treatment. Data about flare‐up were not included since flare‐up was not defined as swelling.
Number of participants who took ibuprofen 400 mg the day after every visit and after obturation on days 1, 7 and 30 Since analgesic use was recorded at different times, only the highest value was extracted. |
|
| Notes | aThe trial authors stated that in group B, the treatment took place over > 3 visits, but they described only 3 sessions. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Randomisation was carried out by designated personnel using manual lottery method". |
| Allocation concealment (selection bias) | Low risk | Quote: "thirty allocation slips in unmarked envelopes were drafted for each group and combined to create the lottery pool". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 60/60 participants evaluated. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias. |
DiRenzo 2002.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: USA Number of centres: 1, University of Illinois, Chicago Setting: university dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 80 Number of teeth: 80 Demographics (e.g. sex, age, ethnic group): not reported Inclusion criteria: mature vital and non‐vital permanent maxillary and mandibular molars requiring root canal therapy Exclusion criteria: pregnancy, use of antibiotics or corticosteroids at time of treatment, immunocompromised states, aged < 18 years Diagnostic criteria for pulpal or periapical disease: not reported Group 1: randomised 46; analysed 39 Group 2: randomised 34; analysed 33 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; in the interappointment period the teeth were closed with a sterile dry cotton pellet and Cavit temporary restorative cement). 2 operators (postgraduate students). Rubber dam isolation. Use of magnification loupes not reported. Canal shaping with hand files and nickel titanium rotary files. Irrigation with 2.5% NaOCl. Working length determined by an EAL and ≥ 2 angled radiographs. Obturation with gutta‐percha and ZOE sealer in lateral condensation. |
|
| Outcomes |
Used modified VAS to measure pain at 6, 12, 24 and 48 hours after first appointment.
Defined as swelling that needed antibiotics and narcotic analgesics (see Table 3) |
|
| Notes | Data on pain were not available and it was not possible to extract them from the tables. Therefore, data on pain were not available for meta‐analysis. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "random assignment by coin toss". |
| Allocation concealment (selection bias) | Unclear risk | Comment: unclear by whom and when the coin toss was performed and how the result was communicated to the operators. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 72/80 (90%) of participants who entered study were included in final analysis. 5 participants (group 1) dropped out because of their inability to complete the treatment in 1 appointment, 3 participants (2 group 1, 1 group 2) did not return the VAS form. |
| Selective reporting (reporting bias) | Low risk | Comment: VAS pain measurements reported. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Dorasani 2013.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: India Number of centres: 1 Setting: not reported Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 57 Number of teeth: 64 Demographics (e.g. sex, age, ethnic group): 27 F, 30 M; mean age 40 years; age range 18–62 years Inclusion criteria: aged 18–62 years, only single rooted teeth with Vertucci's type I configuration, teeth with radiographic evidence of periapical pathology (PAI ≥ 3) and pulpal necrosis Exclusion criteria: any systemic disease; pregnancy; use of antibiotics, corticosteroids or anti‐inflammatory drugs prior to treatment; necessity of antibiotic premedication for dental treatment; previously accessed tooth; grossly decayed tooth (difficulty in rubber dam isolation), teeth with calcified canals and weeping canals Diagnostic criteria for pulpal or periapical disease: not reported Randomised 64 teeth from 57 participants. 6 participants contributed more than 1 tooth: 5 with 2 teeth and 1 with 3 teeth. Group 1: 34 teeth randomised, 23 analysed Group 2: 30 teeth randomised, 21 analysed |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; the second visit 7 days after the first; in the interappointment period a paste carrier was used to carry CH medicament in the root canal and temporarily restored with Cavit) Single operator. Rubber dam isolation. Use of magnification loupes not reported. Canal shaping: hand instrumentation with flexo‐files using balanced force technique and crow‐down technique. Irrigation: 3% NaOCl and saline. Working length checked with EAL and confirmed by Rx. EDTA gel used as a lubricant during shaping. Obturation with gutta‐percha cones and pulp canal sealer (Kerr) with lateral condensation |
|
| Outcomes |
Presence of clinical signs and symptoms at 12 months (spontaneous pain, presence of sinus tract, swelling, mobility, periodontal probing depths greater than baseline measurements, or sensitivity to percussion or palpation)
Change in apical bone density at 3, 6 and 12 months using PAI |
|
| Notes | Participants who had taken medication for any systemic illness during follow‐up were excluded from study. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Comment: 44/64 (70%) of teeth included in study were reported in study. 2 treatment failures before the 12‐month examination (1 in group 1 and 1 in group 2). 18 teeth lost at follow‐up. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | High risk | Comment: number of teeth exceeded the number of participants and it was not specified whether participants were randomised several times equal to the number of teeth undergoing treatment. |
Erdem Hepsenoglu 2018.
| Study characteristics | ||
| Methods | Study design: randomised 3‐arm clinical trial Country: Turkey Number of centres: 1, Medipol University Endodontics Clinic Setting: university dental clinic Recruitment period: January to November 2015 Funding source: not specified |
|
| Participants | Number of participants: 150 Number of teeth: 150 Demographics (e.g. sex, age, ethnic group): aged 18–75 years Pulp status: endodontically treated teeth Inclusion criteria: asymptomatic root canal‐treated teeth in need of non‐surgical endodontic retreatment Exclusion criteria: complicating systemic disease, severe pain or acute apical abscess (or both), aged < 18 years, antibiotic or corticosteroid use, and multiple teeth that required pretreatment to eliminate the possibility of pain referral Diagnostic criteria: radiographic evaluation using panoramic and periapical radiographs Randomisation: method not specified Group 1: randomised 50, analysed 50 Group 2: randomised 50, analysed 50 Group 3: randomised 50, analysed 50 |
|
| Interventions | Group 1: single‐visit retreatment Group 2: multiple‐visit retreatment (2) with the interappointment application of CH introduced using a lentulo as the 7‐day interappointment medication Group 3: multiple‐visit retreatment (2) with the interappointment application of CHX gel. Root canals medicated with 2% CHX gel for 7 days. Teeth were closed with a sterile dry cotton pellet and a minimum of 3 mm ZnO temporary restorative material. Rubber dam isolation. Use of magnification and number of operators not reported. Canals shaping with a crown‐down technique using hand files and NiTi rotary instruments. Working length measured with an EAL. Teeth prepared up to a 40 file 0.5 mm short of the apex. Irrigation performed with 2.5% NaOCl and final irrigation with 2.5 mL 5% EDTA, 2.5 mL 2.5% NaOCl, and 5 mL distilled water. All root canals were dried with paper points (SU 40, Revo‐S, Micro‐Mega). Obturation: epoxy resin sealer introduced into the root canal with master cones using a brushing motion. Accessory gutta‐percha cones were used, when needed, via a non‐compaction technique. |
|
| Outcomes |
Verbal rating scale with well‐defined categories at the 5 time intervals after obturation: 1, 2, 3, 7 and 30 days Each participant was asked to categorise their pain according to the following criteria. 1. No pain: the treated tooth felt normal. 2. Mild pain: the tooth involved was slightly painful for a time, regardless of the duration, but there was no need to take analgesics. 3. Moderate pain: the tooth involved caused discomfort or pain (or both), which was either tolerable or was rendered tolerable by analgesics. 4. Severe pain: the pain caused by the treated tooth disturbed normal activity or sleep, and analgesics had little or no effect. |
|
| Notes | We pooled data from groups 2 and 3. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 150/150 (100%) participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Fonzar 2017.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm clinical trial Country: Italy Number of centres: 2, Dr. Fonzar Centre and Dr. Mollo Centre Setting: private dental practices Recruitment period: February 2009 to January 2014 Funding source: quote "This trial was self‐funded and the authors have no conflict of interests to declare, however, rotary instruments were kindly provided by Sweden & Martina, Due Carrare PD, Italy". |
|
| Participants | Number of participants: 199 Number of teeth: 199 Demographics (e.g. sex, age, ethnic group): aged ≥ 18 years Pulp status: both necrotic teeth and vital teeth Inclusion criteria: any symptomatic tooth requiring endodontic treatment or retreatment because of endodontic infection; any asymptomatic tooth, with a periapical radiolucency of endodontic origin, requiring endodontic treatment or retreatment. Exclusion criteria: any permanent tooth with immature root apex, apicectomised teeth, any symptomatic tooth for which symptoms may not be of endodontic origin, teeth with secreting canal(s) after preparation, necessity to immediately restore the tooth in 1 session because of prosthetic or aesthetic reasons (or both), people referred only for endodontic treatment who could not be followed up at the treating centre. Diagnostic criteria: preoperative periapical radiograph evaluated by the treating clinician. Randomisation: computer‐generated restricted randomisation lists were created. Group 1: randomised 99, analysed 92 Group 2: randomised 100, analysed 90 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 1 week later). Intracanal medicament: CH placed in the canal(s) using a needle or a lentulo spiral. 2 operators. Magnifying devices (×4) were used. Rubber dam isolation. First time treating canals: preliminary working length determined with an EAL and K file 08. Shaping: rotary NiTi instruments. Irrigation: with 5% sodium hypochloride. Diameter of the apex and final working length manually determined using a LightSpeed (LightSpeed Technology, San Antonio, Texas, USA) instrument. The final preparation of the apex made with the LightSpeed or with Profile 0.04 taper (Dentsply Maillefer) For retreatment, the working length was estimated on a periapical radiograph. The obturation material was removed manually, mechanically and by ultrasonic tips, solvents. Final working length determined with EAL Final irrigation: 1 min with 17% liquid EDTA and 5% sodium hypochloride activated by ultrasonic files for 1 min. The canal was dried with sterile paper cones. Obturation: dry non‐standardised gutta‐percha cone immersed for 30 s in a 5% hypochloride solution, dried, coated with a small quantity of ZOE sealer. Vertical condensation of warm gutta‐percha technique was used. |
|
| Outcomes |
|
|
| Notes | Analgesic use was reported as mean average number of ibuprofen tablets; therefore, it could not be extracted. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "two computed – generated restricted randomisation lists were created". |
| Allocation concealment (selection bias) | Low risk | Quote: "Information on how to treat each patient was enclosed in sequentially numbered, identical, opaque, sealed envelopes. Envelopes were opened sequentially after having completed the preparation of the canal(s)". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "Two experienced endodontists not involved in patient treatment evaluated radiographic healing without knowing group allocation". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 17/199 (8.5%) participants dropped out before 1‐year follow‐up. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Gesi 2006.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Italy Number of centres: 2, private dental practices in Pisa and Pistoia, Italy Recruitment period: 24 months Funding source: not reported |
|
| Participants | Number of participants: 256 Number of teeth: 256 Demographics (e.g. sex, age, ethnic group): 141 F, 115 M; age and ethnic group not reported Inclusion criteria: people with teeth with painful and non‐painful vital pulp, with bleeding upon access of the pulpal chamber Exclusion criteria: physical or mental disability, taking pain medication or in treatment with antibiotics for systemic or local infection Diagnostic criteria for pulpal or periapical disease: vitality testing and thermal and mechanical stimulation Group 1: randomised 130; analysed 130 Group 2: randomised 126; analysed 126 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; in the interappointment period CH used as intracanal medication and ZnO paste as temporary restoration) Single operator. Rubber dam. Use of magnification loupes not specified. Canal shaping: hand instrumentation with flexo‐files using balanced force technique and crow‐down technique. Irrigation: 3% NaOCl. Working length established by Rx. Obturation with gutta‐percha and pulp canal sealer (Kerr) with lateral condensation |
|
| Outcomes |
Evaluated 1 week after canal obturation by clinical examination and a verbal rating scale to assess pain experience. Participants with multiple‐visit treatment were asked to evaluate their pain after 1 week for each visit. We considered pain‐related data only after canal obturation. Verbal rating scale graded 0–3; 0 = no, 1 = mild, 2 = moderate and 3 = severe pain. Teeth were also tapped for percussion sensitivity. We considered only 2 categories: pain (mild, moderate, severe) and no pain.
Follow‐up to 3 years. 2 endodontists, experienced in radiographic assessment of endodontic treatments, neither of whom was the operator and both blinded to the assigned group, carried out analysis of the radiographs. Parameters were presence or absence of periapical radiolucency (radiographic lesion). In 2‐ or multi‐rooted teeth; the tooth was classified according to the diagnosis of the worst root. |
|
| Notes | The interappointment pain was evaluated. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "by a simple randomisation procedure (toss of a coin) patients were allocated in group 1 or 2". |
| Allocation concealment (selection bias) | Unclear risk | Comment: unclear by whom and when the coin toss was performed and how the result was communicated to the operators. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "two endodontists, well experienced in radiographic assessment of endodontic treatments, neither of whom was the operator and both masked to the assigned treatment group, carried out the analysis of the radiographs". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100% of those who entered the study were included in the final analysis of the outcome 'pain'. 244/256 of participants who entered the study were included in the final analysis of the outcome 'healing at 3 years' follow‐up'. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Gill 2016.
| Study characteristics | ||
| Methods | Study design: randomised 3‐arm parallel‐group trial Country: India Number of centres: 1, Department of Conservative Dentistry and Endodontics, JCD Dental College, Sirsa, Haryana Setting: university clinic Recruitment period: 2010–2013 Funding source: study authors denied any grant or financial support. |
|
| Participants | Number of participants: 43 Number of teeth: 81 anterior teeth Demographics (e.g. sex, age, ethnic group): aged 16–65 years Pulp status: necrotic teeth Inclusion criteria: presence of radiographically demonstrable AP (minimum size 2.0 mm × 2.0 mm) in maxillary anterior or mandibular anterior tooth/teeth. Both symptomatic and asymptomatic people were included. Exclusion criteria: diagnosis of diabetes, diagnosis of immune‑compromising disease, aged < 16 or > 65 years, tooth had been previously accessed or treated Diagnostic criteria: radiographic diagnosis Randomisation: randomly assigned to the treatment groups by throwing of a die Group 1: initial number not reported, 21 teeth analysed Group 2: initial number not reported, 18 teeth analysed Group 3: initial number not reported, 21 teeth analysed |
|
| Interventions | Group 1: single visit Group 2: multiple (2) visits: after instrumentation, the canal was left empty and access cavity closed with Cavit‐G for ≥ 1 week. Group 3: multiple (2) visits: after instrumentation, the canal was filled with CH‐based dressing and access cavity closed with ZnO cement for ≥ 1 week. Local anaesthesia performed. Single operator. Use of magnification not reported. Use of rubber dam. Initial canal working length established using the EAL and a #15 stainless steel K‑file and confirmed radiographically. Manual step‐back technique instrumentation with K‑files and H‑files. Irrigation with 2.5% NaOCl and 17% EDTA. Canals dried with paper points. At time of obturation, lateral condensation with gutta‐percha points and oxide eugenol sealer was used. Teeth were restored with composite restoration. |
|
| Outcomes |
Secondary outcome measures were the presence of clinical symptoms or abnormal findings at 12 months (spontaneous pain, presence of sinus tract, swelling, mobility or sensitivity to percussion or palpation).
Change in apical bone density (radiographically) at 12 months. Periapical Rx taken with a customised index. Radiographic evaluation using the PAI scoring system. |
|
| Notes | At start of trial, 81 teeth in 43 participants. Then, 5 teeth in 2 participants (1 each in groups 2 and 3) with treatment failure before 1‐year follow‐up. 1 tooth in 1 participant (group not reported) underwent endodontic surgery for a fistula. 2 teeth in 1 participant (group not reported) were extracted for fracture. 16 teeth in 10 participants were lost at 1‐year follow‐up. So 60 teeth in 29 participants were evaluated at 1 year. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "patients were randomly assigned to the treatment groups by throwing of a dice". |
| Allocation concealment (selection bias) | Low risk | Quote: "patients were randomly assigned to the treatment groups by throwing of a dice". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "Radiographic images were evaluated blindly and independently by 4 experienced endodontists by assigning a score according to which of the reference images it appears to match". |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Quote: "Ten patients (16 teeth) were lost to follow‑up". Comment: 23% of participants lost at follow‐up. |
| Selective reporting (reporting bias) | High risk | Comment: clinical symptoms and abnormal findings at the 12‑month follow‑up examination were not reported. |
| Other bias | High risk | Comment: the number of teeth exceeded the number of participants and it is not specified whether participants were randomised a number of times equal to the number of teeth undergoing treatment. |
Gui 2017.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm, parallel‐group clinical trial Country: China Number of centres: 1, Zhuhai Fifth People's Hospital Settings: hospital dental clinic Recruitment period: July 2012 to February 2016 Funding source: no information reported |
|
| Participants | Number of participants: 68 Number of teeth: 68 Demographics (e.g. sex, age, ethnic group): 27 F, 41 M; age range 23–66 years Pulp status: vital teeth Inclusion criteria: not reported Exclusion criteria: not reported Diagnostic criteria: not reported Randomisation: the authors reported that the test group was randomly selected, but the method of randomisation was not described. Group 1: randomised 34, analysed 34 Group 2: randomised 34, analysed 34 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (3). First visit: pulp opening, pulp extraction and length measurement, irrigation, dressing with CH paste. After 5–7 days: shaping. After 7 days: obturation. Number of operators not reported. Rubber dam isolation. Use of magnification not reported. Irrigation with NaOCl and saline. Working length measured with Rx and apex locator. Shaping with NiTi instruments (not otherwise specified) Canal obturation with gutta‐percha and sealer (not otherwise specified). |
|
| Outcomes |
Presence of symptoms and clinical/radiographical signs
Dichotomous pain evaluation |
|
| Notes | The time of postoperative evaluation was not reported so no data could be extracted. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: no participants lost to follow‐up reported. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias detected. |
Gupta 2021.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group trial Country: India Number of centres: 1, Department of Conservative Dentistry and Endodontics, Hitkarini Dental College, Jabalpur, Madhya Pradesh, India Settings: dental college Recruitment period: not reported Funding source: study authors declared no financial support. |
|
| Participants | Number of participants: 70 Number of teeth: 70 Demographics (e.g. sex, age, ethnic group): 40 F, 38 M Pulp status: both necrotic and vital teeth Inclusion criteria: consented to planned single visit or 2‐visit treatment; moderately curved root canals Exclusion criteria: any systemic disease; pregnant; teeth with calcified canals, unusual canal morphology, teeth with extra root or procedural error during treatment; teeth with periapical radiolucency of size > 0.5 cm; received antibiotics or analgesics (or both) immediately after the first appointment of the therapy Diagnostic criteria: not reported Randomisation: random list generated Group 1: randomised 35, analysed 34 Group 2: randomised 35, analysed 34 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit after 1 week). Use of CH dressing. Local anaesthesia was administered. Single operator, rubber dam isolation reported, use of magnification not reported. After access preparation, canals were negotiated, and apical patency preserved with a number 10 K‐file. The working length was determined with K‐file using EAL and confirmed by periapical radiograph. Cleaning and shaping performed with a hybrid technique using hand K‐files and NiTi rotary files for all teeth. Irrigation with 3% NaOCl, EDTA and saline. Canals dried utilising sterile absorbent points. Obturation with gutta‐percha cones and CH‐based sealer utilising the lateral compaction technique. After 1 week of obturation, teeth were restored by composite restoration. |
|
| Outcomes |
Participants recorded their postobturation pain levels using heft‐parker VAS at 6 hours, 12 hours, 1 day and 2 days. Treated teeth evaluated for tenderness to percussion after 1 week of obturation.
Analgesic use was not among the planned outcomes, but data were reported in the results. |
|
| Notes | Data from the Heft‐Parker VAS were shifted to a 0–100 range. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "A random list was generated". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 68/70 (97%) of enrolled participants were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias found. |
Hebatallah 2019.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: Egypt Number of centres: 1, Faculty of Oral and Dental Medicine, Cairo University Settings: university dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 50 Number of teeth: 50 Demographics (e.g. sex, age, ethnic group): aged 18–60 years Pulp status: necrotic teeth Inclusion criteria: necrotic anterior and premolar teeth with no symptoms before treatment Exclusion criteria: pregnancy or lactation, medically compromised, multiple teeth that required treatment in the same quadrant, periapical radiolucency, very severe and abrupt apical curvatures Diagnostic criteria: not reported Randomisation: method not reported Group 1: randomised 25, analysed 25 Group 2: randomised 25, analysed 25 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit after 7 days, root canal medication was not used) Local anaesthesia administered. Isolation with rubber dam. Number of operator or use of magnification not reported. Patency of canals verified with hand K – files size #15. Working length determined with EAL and intra‐oral periapical radiograph to be 0.5–1 mm shorter than radiographic apex. Shaping with rotary NiTi files. Irrigation with EDTA gel and 2 mL 2.6% NaOCl with a 37‐gauge needle at depth 2–3 mm from the working length. After dryness with paper points, root canals obturated using the lateral condensation technique. Cone fitness radiograph taken to ensure proper length. |
|
| Outcomes |
After 6 hours, 24 hours, 48 hours and 7 days postoperatively, using a VAS |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100% of participants analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Ince 2009.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Turkey Number of centres: > 1. Quote: "… patients who attended participating dental clinics …" Setting: not specified Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 306 Number of teeth: 153 vital teeth and 153 non‐vital teeth Demographics (e.g. sex, age, ethnic group): 106 F, 200 M; aged 18–60 years; mean 45 years Inclusion criteria: only 1 tooth that required RoCT, aged 18–60 years of age, in good health Exclusion criteria: having previously taken analgesics or antibiotics Diagnostic criteria for pulp vitality: electric test with pulp testing device Group 1: randomised 153, analysed 153 Group 2: randomised 153, analysed 153 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 7 days after the first, no interappointment medication, a sterile cotton pellet was placed in the pulp‐chamber and the access cavity was sealed with quick‐setting ZOE cement) 2 experienced clinicians performed the treatments. Rubber dam isolation. Use of magnification loupes not specified Canal shaping: step‐back technique, hand files and Gates‐Glidden drills. Irrigation: 2 mL 5% NaOCl; working length determined radiographically; root canals were filled with gutta‐percha points sealed with epoxy resin‐based root canal sealer using lateral condensation technique. |
|
| Outcomes |
Preoperative (absence or presence of pain), postoperative at 3 days after initial appointment (absence or presence of pain; degree of pain: none, slight, moderate, severe). |
|
| Notes | No data reported in text regarding:
We sent an e‐mail to the corresponding author but received no reply. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: not reported. |
| Allocation concealment (selection bias) | Unclear risk | Quote: "The case and the operator distribution were blinded …". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100% of participants were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Jethi 2021.
| Study characteristics | ||
| Methods | Study design: quasi‐randomised clinical trial Country: India Number of centres: 1, Department of Conservative Dentistry and Endodontics, Daswani Dental College and Research Centre, Kota, Rajasthan Settings: university dental clinic Recruitment period: not specified, but conducted for over 2 years Funding source: study authors declared that they had no conflicts of interest. |
|
| Participants | Number of participants: 92 Number of teeth: 100 Demographics (e.g. sex, age, ethnic group): aged 18–60 years Pulp status: vital teeth Inclusion criteria: teeth with symptomatic irreversible pulpitis premolars with uncomplicated single root canal, teeth with a fully formed apex, teeth with no or < 0–1 mm periapical radiolucency, teeth fulfilling indications for both single and multiple visits Exclusion criteria: medically compromised, temporomandibular joint problems/restricted mouth openings, aged < 18 years, using antibiotics or corticosteroids, non‐restorable and periodontal compromised teeth, calcifications of teeth, internal and external resorption cases, mentally disabled, pregnant Diagnostic criteria: not mentioned Randomisation: odd–even method on the basis of the patient's arrival at the outpatient department desk. All odd entrants (1, 3, 5, 7 and 9) were allocated to the single‐visit group, and even entrants (2, 4, 6, 8 and 10) were allocated to 2‐visit groups. The same process was repeated for subgroups, all odd entrants were prepared with hand NiTi files and even entrants were prepared with rotary NiTi files. Group 1: randomised 50 teeth, analysed 50. GA1 (hand instrumentation) 25 teeth + GA2 (rotary instrumentation) 25 teeth Group 2: randomised 50 teeth, analysed 50. GB1 (hand instrumentation) 25 teeth + GB2 (rotary instrumentation) 25 teeth |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2). Canals packed with sterile cotton and temporary restoration Single operator. Use of magnification not reported. Topical anaesthesia and local anaesthesia solution administered. Rubber dam was used. Standard access cavity prepared with diamond burs. Negotiation of the canals with size #10 or #15 K‐files up to about two‐thirds of the estimated working length. Working length of each canal determined by an EAL or ≥ 2 angled radiographs. Hand instrumentation with hand and rotary NiTi files. Irrigation with 2 mL 2.5% NaOCl and EDTA. Final irrigation with 2 mL 17% EDTA for 1 min followed by 2 mL 2.5% NaOCl. Canals were dried with paper points. Obturation with gutta‐percha cones and epoxy resin sealer. Fast Pack used for warm vertical compaction of the GP cones. |
|
| Outcomes |
Recorded with the 100 mm Modified Heft–Parker VAS after the postoperative period of 6 hours, 24 hours, 48 hours and 7 days The postoperative evaluation was recorded as: 0 = no pain; 1 = slight pain/discomfort; 2 = moderate pain relieved by analgesics; 3 = moderate to severe pain not completely relieved by analgesics; 4 = severe pain/swelling not relieved by analgesics and required an unscheduled visit |
|
| Notes | Pain data could not be extracted since mean and SD were estimated from the 0 to 4 scale reported in the outcomes instead of a 0‐ to 100‐mm VAS scale. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Comment: odd–even method used. |
| Allocation concealment (selection bias) | High risk | Quote: "The receptionist had done the allocation. All odd entrees (1, 3, 5, 7, and 9) were allocated to the single‐visit group, and even entrees (2, 4, 6, 8, and 10) were allocated to two‐visit groups". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: all participants were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | High risk | Comment: number of teeth exceeded number of participants and it was not specified whether participants were randomised a number of times equal to the number of teeth undergoing treatment. |
Keskin 2015.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: Turkey Number of centres: 1, Ondokuz Mayıs University Department of Endodontics Settings: university dental clinic Recruitment period: not reported Funding source: no financial support obtained |
|
| Participants | Number of participants: 300 Number of teeth: 300. 150 vital teeth and 138 necrotic teeth. 68 incisor, 98 premolar and 122 molar teeth Demographics (e.g. sex, age, ethnic group): analysed participants were 175 F, 113 M. Pulp status: both vital and necrotic teeth Inclusion criteria: both vital and non‐vital teeth were included with only condition that asymptomatic Exclusion criteria: aged < 18 years, pregnant, taking antibiotics or corticosteroids at time of treatment, immunocompromised, multiple teeth requiring RoCT. By preoperative periapical radiographic examination, teeth with periapical pathosis, calcified canals and immature roots were excluded. Diagnostic criteria: pulp vitality was based on both the result of electric pulp test (Parkell Digitest D626D, Farmingdale, New York, USA) and ultimately clinical observation of haemorrhage in the canal while opening access cavities. Randomisation: method not described Group 1: randomised 150, analysed 140 Group 2: randomised 150, analysed 148 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit 1 week later). Canals were dressed with CH containing medicament paste (Metapaste, Meta Biomed Co, Cheongju City, Korea) and access cavities were sealed with sterile dry cotton pellets and minimum of 3–4 mm of temporary filling material (Cavit G, 3M ESPE Dental AG, Seefeld, Germany). Local anaesthesia with 4% Articaine containing 1:100,000 adrenaline (Ultracaine DS Forte; Aventis Pharma, Istanbul, Turkey) administered. Rubber dam was applied. Number of operators and use of magnification not reported. Working length determined with Root ZX mini apex locator (J. Morita, MFG. Corp. Kyoto, Japan) and periapical radiographs. Shaping with ProTaper Universal rotary NiTi files (Dentsply Maillefer, Ballaigues, Switzerland). Irrigation with 2 mL 5.25% NaOCl (Sultan Chemists Inc, Englewood, Colorado, USA) with a 27‐gauge needle (Life set, Hamburg, Germany). The smear layer was removed using 17% EDTA (Vista dental products, Inter‐med Inc, Racine, Wisconsin, USA) in the canal for 1 min followed by irrigation with 4 mL 5.25% NaOCl. Canals were dried with sterile paper points. Obturation carried out with gutta‐percha points (Diadent; Diadent Group International, Korea) and AH Plus root canal sealer (Dentsply, Maillefer, Ballaigues, Switzerland) using cold lateral compaction technique. |
|
| Outcomes |
Recorded at 24, 48 and 72 hours using a VAS |
|
| Notes | The exact number of vital and necrotic teeth was not reported; therefore, subgroup analyses for necrotic and vital teeth could not be conducted. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "random division". Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 288/300 (96%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Markan 2021.
| Study characteristics | ||
| Methods | Study design: randomised 4‐arm parallel‐group clinical trial Country: India Number of centres: 1, Department of Dentistry, Govt. Medical College and Hospital, Chandigarh Settings: hospital dental clinic Recruitment period: 31 October 2016 to 30 June 2017 Funding source: not reported |
|
| Participants | Number of participants: 168 Number of teeth: 168 Demographics (e.g. sex, age, ethnic group): aged 20–60 years Pulp status: both vital and necrotic teeth Inclusion criteria: aged 20–60 years, having odontogenic pain, systemically healthy (i.e. no risk factor present that can affect oral health), absence of prior hospitalisation and prolonged medication during treatment Exclusion criteria: pregnant, receiving antibiotics or corticosteroids therapy at time of treatment, with complications at time of procedure (calcification, impossibility to achieve apical patency), having swelling and periapical radiolucency (> 5 mm), immunocompromised, having complicated systemic disease, aged < 18 years, unwilling to have treatment Diagnostic criteria: vitality checked with electric pulp test and thermal test (cold test) Randomisation: method of randomisation not reported Group 1: randomised 96, analysed 96. Subgroup III – single‐visit RoCT with conventional files (48, analysed 48) + subgroup IV – single‐visit RoCT with rotary files (48, analysed 48) Group 2: randomised 72, analysed 72. Subgroup I – multiple‐visit RoCT with conventional files (36, analysed 36) + subgroup II – multiple‐visit RoCT with rotary files (36, analysed 36) |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2 or 3 depending on the satisfactory disinfection of the canal). Cotton pack and "Cavit G" (3M ESPE AG, Landsberg am Lech, Germany) placed to ensure tight leakproof coronal seal. Local anaesthesia administration (xylocaine 2%, adrenaline 1:200,000) and rubber dam isolation (Hygenic Dental Dam, Coltene/Whaledent Inc). Single operator. Use of magnification not reported. Participants in subgroup I and subgroup III were treated using conventional 'K' files (Sybronendo files) with conventional step‐back technique. Participants in subgroup II and subgroup IV were treated using rotary Protaper Next files (Maillefer, Dentsply, Switzerland). Canal patency checked with a no. 10 K‐file (Sybronendo). Working length evaluated with Root ZX Mini apex locator (J Morita Europe, Frankfurt, Germany) and ≥ 2 angled radiographs. Irrigation with 5 mL 3% NaOCl and EDTA alternatively with a 30‐gauge irrigating needle 1.5 mm short of its binding point. Irrigant was activated with coronoapical movements. Final irrigation with 5 mL saline and 5 mL 17% EDTA. Obturation carried out with gutta‐percha points and AH plus sealer (Dentsply Maillefer) using lateral condensation technique. |
|
| Outcomes |
Postobturation pain recorded at 6 hours, 12 hours, 24 hours and 1 week using a VAS |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "visual analogue scale performed by the independent observer blinded to the groups". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: no participants loss to follow‐up reported. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Micoogullari Kurt 2018.
| Study characteristics | ||
| Methods | Study design: parallel 2‐arm clinical trial Country: Turkey Number of centres: 1 Settings: university clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 80 Number of teeth: 90 maxillary anterior teeth Demographics (e.g. sex, age, ethnic group): 35 F, 45 M Pulp status: necrotic teeth Inclusion criteria: non‐contributory medical history, mature maxillary anterior teeth with periapical lesions (< 5 mm), diagnosed as asymptomatic apical periodontitis Exclusion criteria: clinical symptoms, drainage, > 5 mm loss of periodontal attachment, previous endodontic treatment, non‐restorable tooth Diagnostic criteria: standard clinical and radiographic examination Randomisation: random allocation to 2 groups Group 1: 37 participants (14 M, 23 F), randomised 45 teeth, analysed 42 teeth, 3 participants lost (3 teeth lost) Group 2: 35 participants (15 M, 19 F), randomised 45 teeth, analysed 40 teeth, 5 participants lost (5 teeth lost) |
|
| Interventions | Group 1: single visit. Root canals irrigated with 5.0 mL 5% EDTA (Merck), 5.0 mL 2.5% NaOCl and 5.0 mL saline solution. Then root canals dried with paper points, and 5.0 mL 2% CHX irrigation performed as final step. Group 2: multiple visits (2). After completion of root canal instrumentation, CH paste (Merck) was placed into root canal using a lentulo spiral (size 40; Mani), and glass–ionomer cement (Ketac‐Molar, 3M ESPE, St Paul, Minnesota, USA) placed as the temporary restoration. After 2 weeks, CH paste removed, and all root canals irrigated with 5.0 mL 5% EDTA followed by 5.0 mL 2.5% NaOCl. Root canal filling and coronal restorations performed with same techniques and materials as described for the single‐visit group. Treatment performed under local anaesthesia. 1 operator with 4 years of experience. Use of magnification (×3.5). Isolation of the tooth with rubber dam. Used Gates‐Glidden drills and K‐files in a step‐back technique. The master apical file size was determined to be ≥ 45. Working length was measured using apex locator and radiograph. Irrigation using 2.5% NaOCl. At time of canal obturation the root canals were dried with paper points, and canal filling carried out using lateral compaction of gutta‐percha and AH Plus sealer. The tooth was restored with composite resin. |
|
| Outcomes |
Follow‐up visits were performed after 6, 12 and 24 months for all participants to assess the clinical and radiographic status of each tooth.
Treatment outcome categorised as 'success' or 'disease'. For 'success', a treated tooth had to be both clinically asymptomatic with score of PAI 1 or PAI 2.
Follow‐up visits were performed after 6, 12 and 24 months for all participants to assess the clinical and radiographic status of each tooth. Used PAI for radiographic evaluation. Treatment outcome categorised as 'success' or 'disease'. For 'success', a treated tooth had to be both clinically asymptomatic and had to receive a score of PAI 1 or PAI 2 (or both). The teeth were categorised as 'diseased' when any clinical symptoms or PAI score ≥ 3 (or both) were present.
Postoperative pain measured using a modified 4‐grade VAS of 1 = no pain, 2 = mild pain, 3 = moderate pain/pain relieved by analgesics, 4 = severe pain or flare‐up, pain, swelling (or a combination of these) not relieved by analgesics and a required unscheduled visit. The VAS was demonstrated to the participants who were asked to record their pain after 24 and 48 hours and were requested to return the forms 2 days later. They were contacted by telephone to ask about the occurrence of postoperative pain if they did not return them.
Flare‐up, pain or swelling (or a combination) not relieved by analgesics and a required unscheduled visit were recorded. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Teeth were randomly assigned to two groups (either OV [1 visit] or TV [2 visits])". |
| Allocation concealment (selection bias) | Low risk | Quote: "Each participant choosing one of the 90 cards on which was written '1' on 45 of them and '2' on to the rest". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "Each examiner analysed and scored the radiographs in both groups blindly, independently and repeated the radiographic scoring after approximately 4 weeks to assess the inter‐ and intra‐observer reliability". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 82/90 (91%) participants enrolled were analysed. 3 in 1‐visit group and 5 in 2‐visit group missing. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Molander 2007.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Sweden Number of centres: 1, Clinic of Endodontics, Public Dental Health Service, Gothenburg, Sweden Recruitment period: not reported Founding source: not reported |
|
| Participants | Number of participants: 94 Number of teeth: 101 Demographics (e.g. sex, age, ethnic group): 47 F, 47 M; mean age 55 years Inclusion criteria: asymptomatic teeth with necrotic pulps and apical periodontitis Exclusion criteria: not specified Diagnostic criteria for periapical disease: radiography Group 1: randomised 53 teeth, analysed 49 Group 2: randomised 48 teeth, analysed 40 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 7 days after the first, CH was used as interappointment medication using a lentulo spiral and access cavity sealed with Coltosol). 4 endodontic specialists performed the treatments. Rubber dam isolation, use of magnification loupes and working length not specified. Canal shaping: nickel titanium instruments for rotary or hand use (or both). Irrigation: 0.5% NaOCl; root canals were filled with gutta‐percha cones using cold lateral condensation technique including rosin chloroform as sealer. |
|
| Outcomes | Healing (radiographic and clinical) at 2 years. 2 examiners independently evaluated all the Rx (previously coded blind and organised in a random order). Observer used a strict definition of periapical disease and reported a positive finding only when absolute certain. In case of disagreement, joint re‐evaluation was performed. The size of periapical radiolucency was assessed by measuring with a ruler its largest horizontal and vertical width. Teeth with symptoms of persisting periapical inflammation: not healed Cases with unchanged/increased size of periapical radiolucency: not healed Teeth with reduced size of periapical rarefaction (sum of horizontal and vertical reduction ≥ 2 mm): uncertain Teeth with complete restitution of periodontal contours: healed Teeth with > 1 root, the least favourable outcome was registered. |
|
| Notes | CONSORT clinical trial 3/12 participants lost to follow‐up died |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Randomisation was performed before the clinical examination using the minimisation method". |
| Allocation concealment (selection bias) | Low risk | Quote: "Randomisation was performed before the clinical examination using the minimisation method". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "All radiographic films obtained preoperatively and at follow‐up were coded blind and organised in random order. Two examiners independently evaluated all radiographs". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 89/101 teeth analysed (12 teeth lost, 12%). |
| Selective reporting (reporting bias) | Low risk | Comment: outcome reported as planned. |
| Other bias | Low risk | Comment: no other source of bias was found. |
Mulhern 1982.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: USA Number of centres: not reported Setting: not reported Recruitment period: not reported Funding source: a Grant‐in‐Aid of research from the Endowment and Memorial Foundation of the American Association of Endodontists |
|
| Participants | Number of participants: 60 Number of teeth: 60 Demographics (e.g. sex, age, ethnic group): 31 F, 29 M; aged 13–75 years; ethnic group reported: 1 Asian, 42 White and 17 Black Inclusion criteria: non‐surgical endodontic treatment of asymptomatic mature single‐rooted teeth with necrotic pulps Exclusion criteria: severe medical conditions, using corticosteroids or anti‐inflammatory drugs, or recent or active antibiotic therapy (or a combination), diagnostic criteria for pulpal or periapical disease: Rx and vitality test Group 1: randomised 30, analysed 30 Group 2: randomised 30, analysed 30 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (3; in the interappointment period no medication was used, only a dry pledget of cotton with a double cement system of Cavit G and zinc oxyphosphate cement in the coronal access cavity was employed). 2 operators (graduate endodontic students). Rubber dam. Use of magnification loupes and canal shaping not detailed. Irrigation: 2.5% NaOCl. Working length not reported. Obturation with lateral condensation was performed using gutta‐percha and Kerr Tubli‐Seal. |
|
| Outcomes |
Evaluated at 48 hours after treatment (by a questionnaire) and at 1 week (clinical examination). Participants with multiple‐visit treatment were asked to complete a questionnaire for each visit.
|
|
| Notes | Participants in the experimental group received free treatment whereas those in the control group were charged the usual clinic fee for treatment. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "The teeth were randomly assigned to group 1 (single visit) or 2 (multiple visits)". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100% of participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | Low risk | Comment: planned outcomes reported. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Özcan 2021.
| Study characteristics | ||
| Methods | Study design: prospective randomised clinical trial Country: Turkey Number of centres: 1, Istanbul University Faculty of Dentistry Department of Endodontics Settings: university dental clinic Recruitment period: not reported Funding source: study authors declared that the study received no financial support. |
|
| Participants | Number of participants: 50 Number of teeth: 50 Demographics (e.g. sex, age, ethnic group): mean age: group 1: 36.2 (SD 11.65) years, group 2: 31.56 (SD 12.21) years, group 3: 40.36 (SD 12.69) years, group 4: 35.96 (SD 14.79) years. Gender distribution: group 1: 15 F, 10 M; group 2: 18 F, 7 M; group 3: 11 F, 14 M; group 4: 18 F, 7 M Pulp status: necrotic teeth Inclusion criteria: negative responses to pulp tests, palpation, percussion and without fistulas or acute swelling Exclusion criteria: medically immunocompromised, requiring antibiotic prophylaxis, diabetes, hypertension, or drug allergies. Teeth with an immature apex; acute dentoalveolar abscess or swelling; root cracks or fractures; internal or external resorption longer than 24 (SD 2) mm; and on which a rubber dam could not be applied. Diagnostic criteria: single‐rooted teeth periapical lesion with a minimum size of 2.0 × 2.0 mm, radiographically Randomisation: random allocation, method not specified Group 1: randomised 25, analysed 25 Group 2: randomised 25, analysed 25 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 1 week later). Ca(OH)2 paste (MM paste, MicroMega, Besançon, France) applied as an intracanal medication. A cotton pellet was placed and the access cavity restored with glass ionomer and Cavit G (3M ESPE, Irvine, California, USA). Obturation procedures were performed as in Group 1. Same operator in all groups. Local anaesthesia administered. Rubber dam isolation. Use of magnification not reported. Orifice openers used to enlarge the coronal third. Working length determined with EAL, and by the paralleling digital radiographic method with use of a special film holder. Shaping with hybrid technique: standard Revo‐S (SC1, SC2 and SU files; #25 06 taper) NiTi rotary system (MicroMega, Besançon, France) and apical shaping files (AS30, AS35 and AS40, #40 06 taper), K‐type hand files (Dentsply Maillefer, Ballaigues, Switzerland) up to #50 and #60. Irrigation with a 30‐gauge endodontic side‐vented needle (Endo‐Eze, Ultradent Products Inc, South Jordan, Utah, USA), and 2 mL 2.5% NaOCl solution. Final irrigation with 5 mL 17% EDTA, 2.5% NaOCl, sterile water and 3 mL 2% CHX. Obturation with gutta‐percha and AH plus sealer using lateral compaction technique. |
|
| Outcomes |
Postoperative pain assessed using VAS at 4, 8, 12 and 24 hours and at 2, 3, 4, 5, 6 and 7 days after treatment. |
|
| Notes | Out of the original 4 groups, 2 were not considered since teeth were submitted to low‐level laser therapy after chemomechanical preparation. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Low risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100/100 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Paredes‐Vieyra 2012.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Mexico Number of centres: 1, School of Dentistry, Universidad Autonoma de Baja California, Tijuana, Baja California, Mexico Study period: February 2009 to December 2011 Funding source: not reported |
|
| Participants | Number of participants: 287 Number of teeth: 300; 282 teeth were included in the final analysis. For participants with > 1 tooth requiring treatment, the treatment of each tooth was separated by ≥ 4 weeks Demographics (e.g. sex, age, ethnic group): 149 F, 138 M; age 18–60 years; mean age 55 years Inclusion criteria: radiographic evidence of apical periodontitis (minimum size 2.0 mm) and a diagnosis of pulpal necrosis confirmed by negative response to hot and cold tests, acceptance of the aims and requirements of the study, in good health, all teeth had non‐vital pulps and apical periodontitis with or without a sinus tract, a negative response to hot and cold pulp sensitivity tests, presence of enough coronal tooth structure for rubber dam isolation, no prior endodontic treatment on the involved tooth, no analgesics or antibiotics used before the clinical procedures. Exclusion criteria: did not meet inclusion requirements, did not provide authorisation for participation, aged < 16 years, pregnant, history of antibiotic use within the past month, diabetic, whose tooth had been previously accessed or endodontically treated. Diagnostic criteria for pulpal or periapical disease: radiographic evidence of apical periodontitis (minimum size ≥ 2.0 mm × 2.0 mm) and a diagnosis of pulpal necrosis confirmed by negative response to hot and cold tests Group 1: randomised 155 teeth, analysed after a 2‐year follow‐up 146 teeth Group 2: randomised 145 teeth, analysed after a 2‐year follow‐up 136 teeth |
|
| Interventions | All treatment sessions were approximately 50 min in length to allow for acceptable time for the completion of treatment for 1 or 2 visits. The study author performed all treatments. Rubber dam isolation. The tooth was disinfected with 5.25% NaOCl. All caries were removed and endodontic access cavities made with sterile high‐speed carbide #331 and Zekrya Endo burs. The working length was established with the Root ZX EAL and confirmed radiographically. The canals were negotiated and enlarged with hand instruments until reaching an ISO #20 at the working length. The coronal portions of the canals were flared with sizes 2 to 3 Gates Glidden burs. Canals were then irrigated with 2.0 mL 5.25% NaOCl. LightSpeedLSX rotary instruments were used to complete the canal preparation to a size #60 for the anteriors and premolars and to a size #45 to #55 for molars. RC‐Prep was used as a lubricant. After completion of canal instrumentation, all canals were irrigated with 2.5 mL 17% EDTA for 30 s followed by a final irrigation with 5.0 mL 5.25% NaOCl using the EndoVac irrigation system. Group 1: single visit. The canals were dried with sterile paper points and obturated at the same appointment by using lateral condensation of gutta‐percha and Sealapex sealer. Access cavities of anterior teeth were etched and restored with Fuji IX. For posterior teeth, a build‐up restoration was placed by using the same etching technique and Fuji IX. Group 2: multiple visits (2; second appointment was scheduled ≥ 1 week after the initial appointment). The canals were dried and CH powder placed with an amalgam carrier and condensed with a size 9 posterior Schilder plugger. The access cavities were sealed with Cavit, and the quality of the CH powder filling was checked radiographically with post‐treatment radiographs. At the second appointment, the CH was removed with hand instruments, and copious irrigation with 5.25% NaOCl followed by 2.5 mL 17% EDTA and a final rinse of 5.0 mL 5.25% NaOCl using the EndoVac irrigation system was performed. For complete removal of the CH, the canals were dried with sterile paper points, and obturation was performed with the same technique described for the 1‐visit group and post‐treatment. |
|
| Outcomes |
The primary outcome measure for this study was classified by using a modification of the Strindberg study used for radiographic healing assessment. Teeth with symptoms of persisting periapical inflammation were scored as not healed as were the cases with periapical radiolucencies that remained unchanged or increased in size.
Outcomes were evaluated at 2‐year follow‐up. |
|
| Notes | CONSORT report Financial incentive to return for follow‐up for clinical and radiograph examination. Discrepancy between data on participants treated for > 1 tooth and total number of teeth: authors stated that, "twenty‐one patients contributed more than 1 tooth", but since the number of participants enrolled is 287 and the number of teeth enrolled is 300, it seems that < 13 participants could have contributed > 1 tooth. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Comment: the participant was randomly assigned to either the 1‐visit or 2‐visit group by using a sequence of random numbers generated by 1 of the investigators by a computer program. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "radiographic images were coded and stored and evaluated blindly and independently by 2 experienced endodontists". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: only 18/300 (6%) teeth lost at follow‐up (9 in each group). |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | High risk | Comment: it is not explicitly stated that participants with > 1 tooth needing treatment were randomised the same number of times. |
Paredes‐Vieyra 2018.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: Mexico Number of centres: 1, Universidad Autonoma de Baja California, Tijuana, Mexico Settings: university dental clinic Recruitment period: November 2014 to December 2016 Funding source: not reported |
|
| Participants | Number of participants: 110 Number of teeth: 110 Demographics (e.g. sex, age, ethnic group): 63 F, 47 M; aged 18–60 years; mean 55 years Pulp status: necrotic teeth Inclusion criteria: teeth with non‐vital pulps and apical periodontitis, with or without sinus tract; a negative response to hot and cold pulp sensitivity tests; presence of sufficient coronal tooth structure for rubber dam isolation; no prior endodontic treatment on the involved tooth; no analgesic or antibiotics were used 5 days before the clinical procedures began. Exclusion criteria: do not meet inclusion requirements; did not provide authorisation for participation; aged < 16 years; pregnant; diabetes; positive history of antibiotic use within past month; tooth had been previously accessed or endodontically treated; teeth with root resorption; immature/open apex, or a root canal in which patency of the apical foramen could not be established. Diagnostic criteria: diagnosis of pulp necrosis determined by hot and cold sensitivity test and radiographically all teeth showed a small and irregular radiolucency at the tooth apex. Randomisation: block of random numbers generated by 1 of the investigators. Group 1: randomised 50 teeth, analysed 46 Group 2: randomised 60 teeth, analysed 51 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit ≥ 1 week after). Interappointment medication of CH powder with distilled water in a creamy consistency. Obturation performed with the same technique described for the single‐visit group. Post‐treatment radiographs were taken and all teeth were restored with a Fuji IX buildup. Local anaesthesia with 2% lidocaine with 1:100,000 adrenaline (Septodont Saint‐Maur des Fosses, France) administered. Rubber dam isolation. 1 operator. Use of magnification loupes not reported; tooth disinfection with NaOCl. Working length was established with #10 K‐file up to the apical foramen as determined by a Root ZX and then confirmed radiographically. Negotiation of the canals with hand instruments until ISO size #20 at working length. The coronal portions were flared with sizes 2–3 Gates‐Glidden burs. Irrigation with 2 mL 2.5% NaOCl using a 24‐Gauge needle during access and a 31‐Gauge NaviTip and EDTA. Shaping performed with reciprocating files R25 files (25.08) and R40 files (40.06). Patency of the apical foramen was maintained during all the techniques by introducing #10 K‐type file at WL. The preparations for all the groups were finished using a #45 file for narrow or curved canals and a #60 file for wide canals. Final irrigation with 2.5 mL 17% EDTA acid for 30 s and with 5.0 mL 5.25% NaOCl using the EndoVac irrigation system. The root canals were dried with sterile paper points. Obturation carried out using lateral condensation of gutta‐percha and Sealapex sealer. Access cavities of anterior teeth were etched and restored with Fuji IX. For posterior teeth, a buildup restoration was placed using the same etching technique and Fuji IX. |
|
| Outcomes |
|
|
| Notes | Data for flare‐up were not extracted because the study authors did not give a definition of flare‐up. Data for pain were not extracted since the recording time was missing. Data for analgesic use were not reported. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "each patient was randomly assigned to either the one‐visit or the two‐visit group by using a block of random numbers generated by one of the investigators". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "all radiographs obtained preoperatively and at follow‐up were coded blind and organised in random order. Two pre‐calibrated endodontists (author not included) independently evaluated all radiographs". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 13 teeth (11.8%), 4 from single‐visit and 9 from multiple‐visit group, were lost at 2 year‐follow‐up. |
| Selective reporting (reporting bias) | High risk | Comment: data for analgesia were not reported in the results. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Paredes‐Vieyra 2020.
| Study characteristics | ||
| Methods | Study design: prospective multicentre, randomised control trial Country: Baja California, Tijuana, Mexico Number of centres: 3 Settings: private dental practice Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 90 Number of teeth: 90 Demographics (e.g. sex, age, ethnic group): 48 F, 42 M; aged 18–60 years Pulp status: necrotic teeth and vital teeth Inclusion criteria: radiographic proof of apical periodontitis (≤ 3 mm x 3 mm in size), and a diagnosis of pulpal necrosis established by the no response to hot and cold tests; in good health; teeth with vital and necrotic pulps with or without apical periodontitis; presence of sufficient coronal tooth structure for rubber dam isolation; no prior endodontic treatment on the involved tooth; no analgesic or antibiotics were used 4 days before the clinical procedures began. Exclusion criteria: did not meet inclusion requirements; did not provide authorisation for participation; aged < 18 years; pregnant; with diabetes or systemic disorders; with a positive history of antibiotic use within the past 2 weeks Diagnostic criteria: radiographic proof of apical periodontitis (≤ 3 mm x 3 mm in size), and a diagnosis of pulpal necrosis established by the no response to hot and cold tests Randomisation: block of random numbers generated by 1 of the investigators Group 1: randomised 30, analysed 30. Group 1a: 15 non‑vital teeth without periapical radiolucency requiring single‐visit RoCT + group 1b: 15 non‑vital teeth without periapical radiolucency requiring 2‐visit RoCT Group 2: randomised 30, analysed 30. Group 2a: 15 non‑vital teeth with periapical radiolucency requiring single‐visit RoCT + group 2b: 15 non‑vital teeth without periapical radiolucency requiring 2‐visit RoCT Group 3: randomised 30, analysed 30. Group CGa: 15 symptomatic teeth with vital pulps requiring single‐visit RoCT + group CGb: 15 symptomatic teeth with vital pulps requiring 2‐visit RoCT |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit ≥ 1 week after). The canals were medicated with a CH powder (Roth, International Ltd, Chicago, Illinois, USA) with distilled water paste. Mepivacaine hydrochloride 2% with levonordefrin 1:20,000 (Septodont, Cambridge, Ontario, Canada) was administered. Tooth was cleaned with 5.25% NaOCl (Ultra bleach, Bentonville, Arkansas, USA) after the rubber dam was positioned. 3 operators. Use of magnification not reported. Access openings made with sterile high‐speed carbide # 331 (SS White, Lakewood, New Jersey, USA). Necrotic teeth with infected canals were prepared by crown‐down technique with copious flushing by 5.25% NaOCl. SmearClear (Kerr Endodontics, Orange, California, USA) lubricant was administered at the entry of all canals. Working length obtained with an apex locator (Root ZX, J Morita, Irvine, California, USA) and contrasted radiographically. The canals were instrumented manually using Flex‐R files until reaching an ISO #20 at the working length. In group 1, twisted file adaptive SM1 (size 20, 0.04 taper) and SM2 (size 25, 0.06 taper) files were used consecutively agreeing to the manufacturer's instructions. In group 2, ProTaper Next Sx files, X1, and X2 (ProTaper Universal system; Dentsply, Ballaigues, Switzerland) were used. X3 and X4 (40/0.06) for preparation of wide canals up to the working length at a speed of 300. Working length was maintained through all the processes used by using a #10 K‐type file at the initial working length estimated. For the control group (group 3), the balanced force technique was employed. Canals were enlarged with hand Flex‐R. EDTA (Roth International Ltd, Chicago, Illinois, USA) was used as a lubricant. Irrigation with 1 mL 2.6% NaOCl, activated ultrasonically with an Irrisafe ultrasonic 20.00 tip. Final irrigation of all groups with 1 mL 17% liquid EDTA (6 °C) with the Endovac system (Discus Dental, Culver City, California, USA) for 1 min and 2 mL cold (6 °C) distilled water. Canals were dried with sterile #35 paper cone and filled by lateral condensation of gutta‐percha and Sealapex sealer (SybronEndo, Orange, California, USA). Access openings of anterior teeth were etched and restored with Fuji IX (GC Corp, Tokyo, Japan). For posterior teeth, a buildup restoration was placed by using the same etching technique and Fuji IX. |
|
| Outcomes |
Using a variation of the Strindberg's study used for radiographic healing assessment.
Experienced during 2 weeks after treatment. Rating for pain: 0 = no pain; 1 = mild pain, any discomfort that did not require urgent treatment; 2 = moderate pain, illness requiring medication; 3 = acute pain, pain that was not relieved by medication and needed palliative management.
Swelling was classified as flare‐up. |
|
| Notes | For the purposes of the review, we combined the groups 1a, 2a and CGa (single‐visit RoCT) and the groups 1b, 2b and CGb (multiple‐visit RoCT). Radiographic assessment and flare‐up were not reported in the results. Pain was recorded after 2 weeks. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "each patient … was randomly assigned to either the one‐visit or the two‐visit group by using a block of random numbers generated by one of the investigators …" |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 3/90 (3.3%) participants were lost at follow‐up. |
| Selective reporting (reporting bias) | High risk | Comment: data for radiographic healing assessment and flare‐up not reported. |
| Other bias | Low risk | Comment: no other source of bias reported. |
Patil 2016.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group open‐label clinical trial Country: India Number of centres: 1, Department of Conservative Dentistry and Endodontics, KLE University Setting: university dental clinic Study period: not reported Funding source: not reported |
|
| Participants | Number of participants: 66 Number of teeth: 66 Demographics (e.g. sex, age, ethnic group): not reported Inclusion criteria: acceptance of the aims and requirements of the study, vital and non‐vital maxillary central incisors that needed endodontic treatment and teeth in which initial master file (K‐type) binds at the apex was of ISO size #45 or less Exclusion criteria: any systemic diseases; pregnancy; aged < 15 years or > 50 years; receiving antibiotics, non‐steroidal anti‐inflammatory drugs or corticosteroids at the time of treatment; acute apical periodontitis; acute apical abscess and weeping canals; necrotic painful teeth with absence of sinus tract for drainage; retreatment cases; teeth with calcified canals; teeth with periapical radiolucencies of diameter > 0.5 cm Group 1: randomised 33, analysed 32 Group 2: randomised 33, analysed 33 |
|
| Interventions | 1 operator performed all treatment. Rubber dam isolation. All caries were removed and endodontic access cavity prepared and canal patency was checked with a size 15K file. Then orifice openers taper 0.12 and 0.10 were used for enlarging the coronal and middle third of the canal, at speed of 350 revolutions per min. RC‐Prep was used as a lubricant and 2.5% NaOCl saline as irrigants. The working length was established with K‐file using apex locator and confirmed radiographically. Instrumentation was carried out using 0.06 taper K3 NiTi rotary files in crown‐down manner along with copious irrigation using 2.5% NaOCl and saline. Group 1: single visit. The canals were dried with sterile paper points and obturated at the same appointment by using lateral condensation of gutta‐percha and AH plus sealer. Temporary restoration was done. Group 2: multiple visits (2; second appointment was scheduled at 1 week after the initial appointment). The canals were dried and double sealed with cavit and phosphate cement. Final obturation was made with a similar method and materials as used in Group 1. |
|
| Outcomes |
Using a modified Heft‐Parker VAS (0–170) at 6, 12, 24 and 48 hours. After 1 week from obturation, final clinical evaluation for pain was done with the vertical percussion method. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "biased coin randomisation". |
| Allocation concealment (selection bias) | Low risk | Quote: "Tossing coin, allocation and sequence was operated by a post‐graduate student". |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | Quote: "unblinded/open label". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 65/66 participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | High risk | Comment: 1 of the outcomes mentioned in the methods section (pain by vertical percussion method at 1 week) was not reported among the results. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Penenis 2008.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: USA Number of centres: 1, Postgraduate Endodontics Clinic, University of Illinois, USA Setting: university dental clinic Recruitment period: 3 years (August 2003 to May 2006) Funding source: research grant from the American Association of Endodontist Foundation |
|
| Participants | Number of participants: enrolled 97, analysed 63 Number of teeth: 63 Demographics (e.g. sex, age, ethnic group): 34 F, 29 M; mean age 54 years; range 18–91 years Inclusion criteria: necrotic teeth with radiographic evidence of apical periodontitis (minimum size ≥ 2.0 mm × 2.0 mm) Exclusion criteria: aged < 18 years, pregnant, positive history of antibiotic use in the previous month, needed antibiotic for dental treatments, diabetic or with tooth previously treated Diagnostic criteria for pulpal or periapical disease: radiography and vital testing performed with cold and electric pulp test Group 1: randomised 49, analysed 33 for PAI at 12 months, analysed 35 for sinus tract formation Group 2: randomised 48, analysed 30 for PAI at 12 months, analysed 31 for sinus tract formation |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit ≥ 2 weeks but ≤ 4 weeks after the first, in the interappointment period a paste made by mixing CH powder with 2% CHX liquid was filled in the canals using a lentulo spiral) Multiple operators. Rubber dam and dental operating microscope use reported. Canal shaping: 0.06 taper K3 NiTi crown‐down technique with RC‐Prep as lubricant. Irrigation: 5.25% sodium hypochloride. Working length established using Root ZX EAL. Obturation with gutta‐percha using warm vertical condensation technique |
|
| Outcomes |
Change in apical bone density at 1 year; the PAI was used to evaluate radiographic healing. Secondary outcomes measures
|
|
| Notes | CONSORT Clinical Trial; financial incentive to join the study. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Patients were randomly assigned to the one‐visit or two‐visit group by using a block of random numbers generated by one of the investigators". |
| Allocation concealment (selection bias) | Low risk | Quote: "Neither the postgraduate clinician nor the patient was aware of the group assignment before agreeing to participate in the study". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "The clinical and radiographic examination was performed by an endodontic resident unaware of the patient's group assignment or baseline presentation". |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Comment: 63/97 (65%) participants (33 from group 1, 30 from group 2) were analysed at 1‐year follow‐up. 16 participants lost in group 1: 2 elected to not participate in follow‐up visits, 12 unable to contact, 2 treatment failures. 18 participants lost in group 2: 1 elected to not participate in follow‐up visits, 16 unable to contact, 1 treatment failure. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Peters 2002.
| Study characteristics | ||
| Methods | Study design: quasi‐randomised parallel‐group clinical trial Country: The Netherlands Number of centres: 1, Academic Centre for Dentistry, Amsterdam, The Netherlands Setting: university dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 39 Number of teeth: 39 Demographics (e.g. sex, age, ethnic group): 19 F, 20 M; mean age 40 years; age range 19–86 years; ethnic groups not reported Inclusion criteria: root with 1 canal, teeth asymptomatic that did not respond to sensitivity testing and never had endodontic treatment, root that showed radiographic evidence of periapical bone loss Exclusion criteria: maxillary molars, aged < 19 years and > 86 years Diagnostic criteria for pulpal or periapical disease: Rx evaluated with PAI score, sensitivity testing Group 1: randomised 21, analysed 21 Group 2: randomised 18, analysed 17 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 4 weeks later). In the interappointment period the canals were dressed with a thick mix of CH in sterile saline and the cavity access filled with 2 layers of Cavit and a glass ionomer restoration. 1 operator (endodontist). Use of rubber dam isolation and magnification loupes reported. Canal shaping: hand instrumentation by double flare technique. Irrigation: 2% NaOCl. Working length evaluated by Rx and EAL Obturation: gutta‐percha and AH 26 sealer in lateral condensation |
|
| Outcomes |
Follow‐up 4.5 years. Routine evaluation during follow‐up: 3, 12, 24 months to 4.5 years. The authors evaluated the treatment outcome as: score A (success: the width and contour of the periodontal ligament is normal, or there is a slight radiolucent zone around excess filling material); score B (uncertain: the radiolucency is clearly decreased but additional follow‐up is not available); score C (failure: there is an unchanged, increased or new periradicular radiolucency). We considered only 2 categories: success (score A) and failure (score B and C) (see Table 1). |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quote: "The teeth were randomly divided into two treatment groups, every second patient was assigned to group 2". Comment: quasi‐random method. |
| Allocation concealment (selection bias) | High risk | Comment: alternative assignment (randomly and consecutively, quasi‐random method). |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "Three experienced endodontists who had not been involved in the treatment or follow‐up appointments were asked to analysed the radiographs". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quote: "All patients returned for follow‐up. One series of radiographs was excluded because of imperfections of radiographic technique". Comment: 38/39 participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Pragya 2016.
| Study characteristics | ||
| Methods | Study design: randomised 4‐arm parallel‐group clinical trial Country: India Number of centres: 1 Settings: university dental clinic Recruitment period: not reported Funding source: study authors declared no source of support. |
|
| Participants | Number of participants: 100 Number of teeth: 100 Demographics (e.g. sex, age, ethnic group): aged 19–50 years Pulp status: vital teeth Inclusion criteria: aged 19–50 years with non‐contributory medical history and people who accepted the proposed procedure together with criteria for postoperative pain evaluation. Teeth with fully formed apices, no calcified canals, no internal/external resorption were selected. Exclusion criteria: pregnancy, receiving antibiotics or corticosteroids at time of treatment, immunocompromised or with any systemic diseases, temporomandibular joint problems or limited mouth opening, gaggers, alcoholic, and teeth with anatomic aberrations, periodontal disease or periapical pathosis, teeth in which rubber dam could not be used If a mandibular premolar showed anatomy other than type I and mandibular molar showed atypical anatomy, they were excluded from the study. Diagnostic criteria: not reported Randomisation: method of randomisation not reported Group 1: randomised 50, analysed 50. Subgroup Ia: single‐rooted mandibular premolars + subgroup IIa: multirooted mandibular molars Group 2: randomised 50, analysed 50. Subgroup Ib: single‐rooted mandibular premolars + subgroup IIb: multirooted mandibular molars |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment after 1 week). A sterile dry cotton pellet without any medicament was placed and sealed with Orafil‐G Prevest Denpro (non‐eugenol temporary filling material). Teeth were obturated and restored as in group 1. Preoperative radiographs taken at normal angulation and 25 mesial angulation Use of rubber dam reported. Use of magnification and number of operators not reported. Local anaesthesia was administered. Initial caries excavation was performed and a standard access cavity was prepared. Working length measure technique not described. Shaping with rotary Protapers with Endo mate DT, all instruments were coated with glyde (Dentsply, USA). Irrigation with 2 mL 3% NaOCl after each instrument. Final irrigation with 5.0 mL 17% EDTA for 1 min followed by 5.0 mL 3% NaOCl and final irrigation with saline. Canals were dried with sterile paper points. Obturation carried out with Protaper gutta‐percha points using ZOE as a sealer |
|
| Outcomes |
Evaluation of pain at 12 hours, 24 hours, 48 hours, 72 hours and 1 week postobturation with a Heft‐Parker VAS (170 mm) and as a dichotomous variable (yes/no)
Mean and SD of number of analgesics taken in various subgroups |
|
| Notes | Data from the Heft‐Parker VAS were standardised to a 0–100 range. Analgesic use was reported as mean and SD of number of analgesics taken and could not be extracted. Data from subgroups I and II of both groups were pooled. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable as radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: all outcomes reported as planned. |
| Selective reporting (reporting bias) | Low risk | Comment: 100/100 participants reported back. |
| Other bias | Low risk | Comment: no other source of bias found. |
Qi 2011.
| Study characteristics | ||
| Methods | Study design: 2‐arm parallel clinical trial Country: China Number of centres: 1, Urumqi Stomatological Hospital Settings: hospital dental clinic Recruitment period: July 2007 to July 2008 Funding source: not reported |
|
| Participants | Number of participants: 209 Number of teeth: 232 (51 anterior, 69 premolars, 112 molars; according to disease classification, 78 pulpitis, 99 apical inflammation, and 36 non‐infected teeth, 19 root canal retreatment) Demographics (e.g. sex, age, ethnic group): not reported Pulp status: both necrotic and vital teeth Inclusion criteria: aged 18–65 years of age; with pulpitis and apical inflammation requiring RoCT; non‐infected teeth (dental trauma, restoration requires pulp RoCT, deep caries penetration); teeth indicated for retreatment (underfilling, 3‐dimensional insufficiency) Exclusion criteria: systemic diseases; severe alveolar bone destruction in periodontal disease; unwilling to co‐operate; pregnant (first 3 months, last 3 months); retrograde infection; calcified and severely curved root canals; teeth longitudinally fractured; acute apical periodontitis, with x‐ray low‐density shadows around the apex > 5 mm Diagnostic criteria: not specified Randomisation: participants were divided into 4 categories according to type of disease, and then randomly grouped within the range of different types Group 1: randomised 119, analysed 119 Group 2: randomised 113, analysed 113 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (number of visits unknown). CH paste was placed in the root canal and the tooth was temporarily sealed with ZOE for 1 week. Number of operators not reported. Use of magnification not reported. Use of rubber dam. Canal shaping with manual 8, 10, 15 K files and rotary NiTi files (Protaper) with a crown down technique. Working length was verified with an apex locator. Irrigation: alternately with 2.5% NaOCl + 17% EDTA. Ultrasonic activation of irrigants. The canals were dried with paper cones and obturated with gutta‐percha and sealer (cortisomol) with cold lateral condensation technique. ZOE cement used for temporary closure, and radiograph taken to understand root condition. |
|
| Outcomes | Clinical and radiological assessment
Pain
|
|
| Notes | Pain grade 1 and 2 were reported together, so the data could not be extracted. No data could be extracted from this study. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Comment: 44/232 (19%) teeth were lost at 1‐year follow‐up. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | High risk | Comment: the number of teeth exceeded the number of participants and was not specified whether participants were randomised several times equal to the number of teeth undergoing treatment. |
Rana 2019.
| Study characteristics | ||
| Methods | Study design: randomised clinical trial Country: Pakistan Number of centres: 1, Department of Operative Dentistry, College of Dentistry, BAMDC, Multan, Pakistan Settings: university dental clinic Recruitment period: 15 December 2017 to 14 June 2018 Funding source: study authors declared no potential conflicts of interest. |
|
| Participants | Number of participants: 140 Number of teeth: 140 Demographics (e.g. sex, age, ethnic group): group 1: 70 participants aged 12–40 years; mean age 26 (SD 7.7) years; group 2: 70 participants aged 12–40 years; mean age 25 (SD 7.6) years Pulp status: both vital and necrotic teeth Inclusion criteria: people aged 12–40 years with carious exposure of permanent teeth, teeth having no preoperative pain on percussion Exclusion criteria: extensive intracanal calcification; incompletely formed apex; teeth had received any endodontic treatment previously; receiving analgesics, anti‐inflammatory drugs, antibiotics, corticosteroids or tricyclic antidepressants; pregnancy and lactation; allergic to endodontic medication; teeth with grade II or III mobility (> 2 mm); systemic disease; immunocompromised; aged < 12 or > 40 years; acute periodontitis and acute apical abscess; teeth with weeping canals; teeth with periapical radiolucencies of diameter > 0.5 cm Diagnostic criteria: preoperative radiographic examination and thermal pulp testing. Diagnosis of the non‐vital pulps determined by history, clinical examination, lack of response to thermal and electrical pulp tests, and radiographs. Randomisation: double‐blind lottery method Group 1: randomised 70, analysed 70 Group 2: randomised 70, analysed 70 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit after 7 days). Teeth were sealed with a sterile dry cotton pellet and double seal with cavit and zinc phosphate cement. Obturation on the second visit. Infiltration of local anaesthetics, rubber dam application, caries excavation if present and access preparation. Use of magnification not reported. Number of operators not reported. Whole procedure performed under supervision of a consultant with > 5 years of postgraduate experience. After access of cavity, preparation pulp chamber was flooded with 2.6% NaOCl solution. Pulp extirpation was done in vital cases. Canal patency was checked with a size 15 K file and working length was achieved. Canals were prepared in coronal third with peso‐reamers and gate‐glidden drills after taking the working length. Remaining two‐thirds of canals were prepared with k‐files. In the remaining apical two‐third part of the canal, hand instrumentation was done by using 2.6% NaOCl as an irrigant while step‐back technique was followed. After instrumentation was complete, canals were dried with paper points. Regardless of group assignment, the teeth were prepared to the same end points at the first appointment. Lateral compaction technique for canal obturation |
|
| Outcomes |
After 24 hours with a Heft‐Parker VAS. Each participant's mark was assigned a value between 0 and 170. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "double blind lottery method technique". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 140/140 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias found. |
Rao 2014.
| Study characteristics | ||
| Methods | Study design: quasi‐randomised parallel‐group clinical trial Country: India Number of centres: 1 Setting: not specified Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 148 Number of teeth: 148 Demographics (e.g. sex, age, ethnic group): aged 18–50 years; sex and ethnic groups not reported Pulp status: necrotic teeth Inclusion criteria: root with single uncomplicated canal with full formed apex (anterior teeth), non‐vital teeth: negative test of pulpal sensitivity by thermal stimuli prior to anaesthesia and no bleeding response on access to the pulp Exclusion criteria: people with multiple teeth that required treatment, non‐restorable teeth, teeth affected by periodontal diseases, aged < 18 years, affected by systemic diseases, affected by severe pain or acute periapical abscesses, using antibiotics or corticosteroids Diagnostic criteria for pulpal or periapical disease: Rx evaluated with PAI score, sensitivity testing Group 1: randomised 74, analysed 74 Group 2: randomised 74, analysed 74 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 1 week later the first). In the interappointment period, the canal was sealed with a sterile dry cotton pellet and a temporary filling material. Rubber dam isolation. Use of magnification loupe not specified. Canal shaping: combination of hand files (K files) and ProTaper, engine‐driven rotary nickel titanium files using hybrid technique. Irrigation with 2.5% NaOCl. Working length evaluated by EAL and ≥ 2 angled radiographs. Obturation: gutta‐percha cones and resin sealer using lateral condensation technique |
|
| Outcomes |
Postobturation, using a VAS (0–4: 0 = no pain, 1 = slight pain/discomfort, 2 = moderate pain relieved by analgesics, 3 = moderate to severe pain not completely relieved by analgesics, 4 = severe pain/swelling not relieved by analgesics and required unscheduled visit) form filled by participants at 6, 24, 48 hours and 7 days after treatment
|
|
| Notes | Data for analgesic use were not reported in the results. Data for pain could not be extracted since mean and SD were not reported in the results. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quote: "the patients were randomly assigned to either the one‐visit or two‐visit by using a set of random numbers generated buy one of the investigators". |
| Allocation concealment (selection bias) | Unclear risk | Comment: alternative assignment (randomly and consecutively, quasi‐random method). |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 148/148 (100%) of participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | High risk | Comment: data for pain and analgesic use were not reported in the results. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Riaz 2018.
| Study characteristics | ||
| Methods | Study design: randomised 2‐arm parallel‐group clinical trial Country: Pakistan Number of centres: 1, Department of Operative Dentistry, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan Settings: university dental clinic Recruitment period: January to June 2016 Funding source: no source of founding reported |
|
| Participants | Number of participants: 60 Number of teeth: 60 Demographics (e.g. sex, age, ethnic group): 34 (55%) F, 26 (45%) M; mean age 38.8 (SD 12.3) years Pulp status: necrotic teeth Inclusion criteria: aged 18–60 years, single‐rooted teeth of both upper and lower arch, necrotic teeth with infected root canals, teeth with periapical lesions and asymptomatic necrotic pulp Exclusion criteria: teeth with previous endodontic treatment, acute apical abscess and extraoral swelling or sinus tract; terminally ill people; people with learning disabilities. Diagnostic criteria: necrotic teeth were diagnosed by negative response to pulp sensibility tests, including heat test, cold test, and electric pulp testing Randomisation: method of randomisation not reported Group 1: randomised 30, analysed 30 Group 2: randomised 30, analysed 30 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit after 5 days). CH (Roth International Ltd) used as intracanal medicament using a lentulo spiral and sealed with sterile cotton and temporary restoration such as cavit. Radiographs were taken before the procedure to check for the presence of any apical radiolucency in the periapical region. Local anaesthesia using 2% lidocaine with 1:100,000 adrenaline (MedicaineR) given. Rubber dam (Henry Schein) used. Number of operators and use of magnification not reported. Access was gained using Round bur (Mani) and Endo Z bur (Dentsply). Endo probe (Hu‐Friedy) was used to locate the canals. Glide path was established using Proglider (Dentsply). Pulpectomy was done using barbed broaches (Mani). Working length established by radiographic method using #15 or #20 file. Canal instrumentation performed using NiTi Rotary Protaper Next system (Dentsply) to ×2 and ×3. Irrigation with 5.25% NaOCl and final wash with 10 mL EDTA. Canals were dried using paper points. Obturation carried out by lateral condensation method using endomethsone (Sepodont) as a sealer. The access cavity was sealed with glass ionomercement (Fuji). |
|
| Outcomes |
Evaluated within 48 hours after the procedure with VAS (0–4 no pain, 5–10 pain) |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "each patient was assigned a computer‐generated list of random numbers with a randomisation ratio of 1:1 produced by random allocation software". |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 60/60 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcome reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Risso 2008.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Brazil Number of centres: 1, Endodontics Clinic of the School of Dentistry of Federal University of Rio de Janeiro, Brazil Setting: university dental clinic Recruitment period: not reported Funding source: Brazilian Grant from CAPES and FAPER |
|
| Participants | Number of participants: 121 enrolled Number of teeth: 121 teeth, 118 included in the final analysis Demographics (e.g. sex, age, ethnic group): 70 F, 48 M; aged 11–18 years; mean age 13.6 years Inclusion criteria: healthy; no analgesics, antibiotics or anti‐inflammatory drugs during the 10 days prior to beginning of treatment; aged 11–18 years; lower first or second permanent molar presenting complete root formation and necrotic pulp with or without symptoms; absence of periodontal disease, pulp calcification or acute dentoalveolar abscesses Exclusion criteria: aged < 11 or > 18 years, teeth with haemorrhage in the canal during medication Diagnostic criteria for pulp necrosis were determined with pulp testing (cold test), percussion‐palpation, examination and direct observation of the presence or absence of haemorrhage in the canal Group 1: randomised not reported, analysed 57 Group 2: randomised not reported, analysed 61 |
|
| Interventions | Group 1: single visit Group 2: multiple visit (2; second appointment 10–12 days after the first). In the interappointment period, the canals were medicated with CH paste and sterile distilled water with lentulo spiral and the complete filling of the canal was verified through periapical radiography. A dry‐sterile cotton pad was sealed in the pulp chamber with a minimum of 3 mm thickness temporary filling restoration (cavit). Single operator (first study author, RPA). Rubber dam isolation, magnification loupes not reported. Canal shaping: middle coronal preflaring with hand instruments: (initial passive instrumentation and Gates‐Glidden burs). Ideal working length determined by an EAL and periapical radiography. Irrigation using 5.25% NaOCl solution, then 10% citric acid and 5.25% NaOCl solution and then 5% sodium thiosulfate. Obturation with gutta‐percha cones using a lateral compaction filling technique as well as ZOE‐based root canal sealer. Teeth filled with light‐cured resin. |
|
| Outcomes |
Preoperative and postoperative measured with VAS (0–5: 0 = no, 1–5 = yes) in a 10‐day period (6, 12 and 24 hours during the first day and then every 24 hours during the 9 following days). VAS of 4 or 5 were considered flare‐up. |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Randomisation was performed using a random numbers listed in a table". |
| Allocation concealment (selection bias) | Unclear risk | Comment: not reported. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 121 participants enrolled; 118/121 (97.5%) evaluated in the final analysis (3 participants were excluded because they missed the obturation visit). |
| Selective reporting (reporting bias) | High risk | Comment: analgesic use not reported in the results. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Shubham 2021.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Nepal Number of centres: 1, Department of Conservative Dentistry and Endodontics, Universal College of Medical Sciences, Bhairahawa, Nepal Setting: university dental clinic Recruitment period: April to December 2019 Funding source: study was not funded by any organisation or company. |
|
| Participants | Number of participants: 160 Number of teeth: 160 Demographics (e.g. sex, age, ethnic group): not reported Pulp status: necrotic and vital teeth Inclusion criteria: not reported Exclusion criteria: complex cases such as pulp canal obliteration, procedural accidents, variable anatomy where maintaining patency is difficult, retreatment cases, teeth with periapical radiolucency and swelling, pregnancy, patients who were medically compromised and people receiving analgesic medication within last 3 days Diagnostic criteria: clinical (including electric pulp test) and radiographic evaluation Randomisation: equal proportion of randomisation allocation ratio Group 1: 80 participants (40 patency, 40 non‐patency) Group 2: 80 participants (40 patency, 40 non‐patency) In each group, there were equal numbers (40) of vital, necrotic, anterior and posterior teeth. |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2). Intracanal medication with CH. Temporarily obturation with Cavit. Canal obturation performed after 1 week. Local anaesthesia was administered. 1 operator. Use of magnification not reported. Isolation of the tooth with rubber dam. Root canals were instrumented by hand K files with step‐back technique. Working length measured radiographically and electronically. Irrigation with 5% NaOCl, sterile 0.9% saline and 2% CHX. At the time of obturation lateral condensation technique was used with gutta‐percha points and AH plus sealer. Direct composite restoration |
|
| Outcomes |
Used 0–10 NRS (NRS‐11) to measure preoperative and postobturation pain at 1, 2 and 7 days. |
|
| Notes | No data could be extracted since pain values were reported as mean rank. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "An equal proportion of randomisation allocation ratio for the two groups was done by shuffled deck of cards with number assigned (i.e. even number for patency group and odd number for non‐patency group)". |
| Allocation concealment (selection bias) | Low risk | Quote: "Number of visits were allocated by another set of equal proportion of envelopes containing concealed assignment codes". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 160/160 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Singh 2012.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: India Number of centres: 1, Department of Conservative Dentistry and Endodontics, Darshan dental College, Udaipur, Rajasthan, India Setting: university dental clinic Recruitment period: not reported Founding source: not reported |
|
| Participants | Number of participants: 200, 188 included in the final analysis Number of teeth: 188 Demographics (e.g. sex, age, ethnic group): 83 F, 105 M; aged 20–60 years Inclusion criteria: aged > 18 years, healthy. Only 1 tooth with a single root of each participant was included. Exclusion criteria: pregnant, taking antibiotics or corticosteroids at time of treatment, affected by complicating systemic diseases or immunocompromised, aged < 18 years. Any tooth with periodontal disease or periapical radiolucency of > 0.5 cm was excluded. Diagnostic criteria for pulp vitality were based on the results of electric pulp tester and by direct clinical observation of haemorrhage in the canal, without considering the clinical diagnosis as being normal pulp, reversible pulpitis or irreversible pulpitis. All teeth had completely formed foramina and no calcified canals, which were preliminary evaluated by preoperative periapical radiographs. Group 1: randomised 100 participants, analysed 94 Group 2: randomised 100 participants, analysed 94 |
|
| Interventions | Group 1: single visit Group 2: multiple visit (2; second appointment 7 days after the first). No intracanalar medication in the interappointment period but a dry‐sterile cotton pellet was placed in the pulp chamber and the access was sealed with a temporary filling restoration, Cavit‐G). Rubber dam isolation. Use of magnification loupes not reported. Working length determined by EAL. Canal shaping: combination of hand files and ProTaper engine‐driven rotary NiTi files. RC‐Prep used as lubricant. Irrigation using 2.5% NaOCl. Obturation using ProTaper universal gutta‐percha and AH plus sealer using lateral compaction technique and restored with temporary restorative material, Cavit‐G |
|
| Outcomes |
Preoperative and postobturation at 6, 12, 24 and 48 hours after obturation) measured with Heft‐Parker VAS |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Patients were randomly assigned to either one‐or two‐visit treatment by biased coin randomisation, a dynamic randomisation method, which was specially designed to get the same number in both groups and the sequence…". |
| Allocation concealment (selection bias) | Low risk | Quote: "… tossing coin and allocation were operated by a graduate student who was blind to the nature of the study". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 12/200 (6%) participants (6 from each group) were excluded from the study because they did not attend the recall visits. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Sun 2020.
| Study characteristics | ||
| Methods | Study design: 2‐arm parallel‐group clinical trial Country: China Number of centres: 1, Inner Mongolia Ordos Central Hospital Settings: hospital dental clinic Recruitment period: March 2018 to March 2019 Funding source: no information available |
|
| Participants | Number of participants: 120 Number of teeth: 120 teeth Demographics (e.g. sex, age, ethnic group): 52 F, 68 M; aged 16–65 years Pulp status: vital teeth (acute pulpitis) Inclusion criteria: acute pulpitis; able to participate voluntarily and sign informed consent; approved by the hospital ethics committee Exclusion criteria: mental disorders or severe communication disorders; poor treatment compliance or extreme non‐co‐operation Diagnostic criteria: no information available Randomisation: yes, but method not reported Group 1: randomised 60, analysed 60 Group 2: randomised 60, analysed 60 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2). In the 7 days interappointment period the teeth were medicated with CH paste and temporary obturated with ZOE paste) Number of operators not reported. Rubber dam isolation. Use of magnification not reported. Irrigation using 2.5% NaOCl. Working length measured with Rx and apex locator (Root ZX). Shaping with Protaper to F2. EDTA gel used for lubrification. Canal obturation with 0.04 gutta‐percha cone and sealer (AH‐plus) using vertical condensation technique |
|
| Outcomes | Pain
|
|
| Notes | No data could be extracted since the time of VAS evaluation was not reported. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: no participants lost to follow‐up reported. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias found. |
Tarale 2013.
| Study characteristics | ||
| Methods | Study design: randomised 3‐arm parallel‐group clinical trial Country: India Number of centres: 1, Sinhgad Dental College & Hospital Settings: postgraduate endodontic clinic Recruitment period: not reported Funding source: no source of support |
|
| Participants | Number of participants: 60 Number of teeth: 60 Demographics (e.g. sex, age, ethnic group): not reported Pulp status: vital and necrotic teeth Inclusion criteria: maxillary and mandibular first molars, presence of sinus tract, teeth with irreversible pulpitis with or without apical periodontitis Exclusion criteria: positive history of antibiotic use within the past month, pregnant, needing antibiotic premedication for dental treatment (including infective endocarditis, prosthetic joint and immunocompromised disorders), diabetes, with acute apical abscess, teeth with weeping canals, teeth with periapical radiolucency > 0.5 cm Diagnostic criteria: not reported Randomisation: method not reported Group 1: randomised 20, analysed 20 Group 2: group with interappointment dressing (randomised 20, analysed 20) + group without interappointment dressing (randomised 20, analysed 20) |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second visit after 1 week). Interappointment dressing with CH (Prime Dental, India) mixed with saline. Access cavities were sealed with a double seal of Cavit G (3M ESPE, Germany) and IRM (Dentsply, Milford, Delaware, USA). The group without interappointment dressing was closed with a sterile dry cotton pellet. Local anaesthesia administration (xylocaine 2%, adrenaline 1:2,00,000), rubber dam isolation (Hygenic Dental Dam, Coltene/Whaledent Inc, Burgess Hill, UK) and disinfection of the operating field (30% hydrogen peroxide and 10% iodine). Number of operators and use of magnification not reported. Pulp was extirpated with barbed broaches (Pulpdent, Switzerland). Irrigation with 2 mL 3% NaOCl (Comdent India), with a 23‐gauge needle (Becton, India), 5 mL 3% NaOCl and 17% EDTA (RC‐Help, Prime Dental). Working length established with Propex EAL (Dentsply Maillefer, Ballaigues) and a ISO size #15 stainless steel K file. Working length confirmed radiographically using paralleling technique and 2 angled radiographs (200 mesial and distal). Shaping with Protaper NT System (Dentsply Maillefer, Ballaigues, Switzerland). Final irrigation with 17% EDTA for 1 min, 5 mL 0.9% saline and with 5 mL 2% CHX (ICPA India) for 1 min. Canals were dried with sterile paper points. Obturation technique with 6% gutta‐percha points (Dentsply Maillefer, Ballaigues, China) and epoxy resin‐based sealer AH Plus (Dentsply Maillefer, Konstanz, Germany) |
|
| Outcomes |
Evaluated at 6, 12, 24 and 48 hours using a 0–170 VAS |
|
| Notes | Results from group 2 and 3 were pooled for data analysis. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 60/60 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Tarallo 2018.
| Study characteristics | ||
| Methods | Study design: randomised, single‐blind, comparative clinical trial Country: Brazil Number of centres: 1, Dental Specialty Center of the city of Bragança Paulista, São Paulo, Brazil Settings: university dental clinic Recruitment period: from January to June 2016 Funding source: none |
|
| Participants | Number of participants: 48 Number of teeth: 48 maxillary or mandibular single‐rooted teeth showing the presence of 1 root canal with straight (0–5°) to moderate (10–20°) curvature; pulp necrosis and asymptomatic apical periodontitis Demographics (e.g. sex, age, ethnic group): 30 F, 18 M; aged 18–71 years; mean age 40 years Pulp status: necrotic teeth Inclusion criteria: aged > 18 years, permanent maxillary or mandibular single‐rooted teeth showing the presence of 1 root canal with pulp necrosis and asymptomatic apical periodontitis Exclusion criteria: any medicament (i.e. non‐steroidal anti‐inflammatory, analgesics of any type, opioids, or corticoids) during the last 24 hours that could alter the perception of pain or interfere with the post‐treatment pain score analysis; with any uncontrolled systemic disease Diagnostic criteria: negativity to pulp sensitivity tests, apical palpation, horizontal and vertical percussion tests, and periapical radiographs (to evaluate the presence or absence of periapical lesions) Randomisation: participants were randomly allocated to 1 of 4 groups using a randomised list generated in a computer program. Groups: patients were randomised into 4 groups: SV0 group: single‐visit RoCT and instrumentation performed on foraminal working length; SV+1 group: single‐visit RoCT and instrumentation performed 1 mm beyond the apical foramen TV0 group: 2‐visit RoCT and instrumentation performed on foraminal working length; TV+1: 2‐visit RoCT and instrumentation performed 1 mm beyond the apical foramen. For the purposes of the review, SV0 and SV+1 groups (single visit) and TV0 and TV+1 groups (multiple visits) were combined. Group 1: randomised 24, analysed 24 Group 2: randomised 24, analysed 24 |
|
| Interventions | Group 1 (SV0 plus SV+1): single visit Group 2 (TV0 plus TV+1): multiple visits (2). The root canals were filled with CH paste and the teeth were sealed provisionally with glass ionomer cement. After 7 days, the intracanal medication was removed using #15 K‐type hand file and 3 mL 2.5% NaOCl and the canals were filled. Description of intervention: before local anaesthesia, bite force examination using a gnathodynamometer was performed. Single operator. Use of magnification not reported. Isolation of the tooth with rubber dam. A Glide path was established with #15 K‐type hand file. Shaping was performed with reciprocating single‐file instrument Reciproc. The R25 files (25.08) were used in narrow and curved canals, and R40 files (40.06) were used in large canals. Canal patency was maintained in all groups by passing a #10 or #15 K‐type file (Dentsply) 1.0 mm beyond the apical foramen. Working length was measured using apex locator and confirmed radiographically. In SV0 and TV0 groups, the working length used was 0 mm from the apical foramen. In the SV+1 and TV+1 groups, the working length was 1 mm beyond the "APEX" or "0.0" mark. The working length was confirmed radiographically. Irrigation was done using 2.5% NaOCl and 17% EDTA ultrasonically activated. The final wash was done using 2.5% NaOCl. The canals were dried with paper points. At the time of obturation, single cone technique Reciproc gutta‐percha cones and AH‐Plus sealer was used. After obturation, glass ionomer cement was placed to seal the access cavity. At the end of the treatment, an x‐ray was done. |
|
| Outcomes |
All participants used a VAS to record their assessment of pain at 3 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours and 7 days after the endodontic treatment. Mechanical allodynia was also evaluated (data not included in the current review). |
|
| Notes | It was not possible to extract pain data from the tables or the figures. We contacted the author but her response was inconclusive. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The participants were randomly allocated to one of the groups by means of a randomised list generated in a computer program". |
| Allocation concealment (selection bias) | Low risk | Quote: "Sealed opaque envelopes containing the treatment for each patient were numbered following the generated list and were opened by the operator only at the moment of the intervention". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 48/48 (100%) of participants enrolled were analysed. |
| Selective reporting (reporting bias) | Low risk | Comment: outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Trope 1999.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: USA Number of centres: 1, School of Dentistry, University of North Carolina, USA Setting: university dental clinic Recruitment period: not reported Funding source: not reported |
|
| Participants | Number of participants: 81 Number of teeth: 102 teeth (61 participants had 1 tooth to treat, 18 had 2, 2 had 3) Demographics (e.g. sex, age, ethnic group): 54 F, 27 M; mean age 44.6 years; age range 19–79 years Inclusion criteria: presence of radiographically demonstrable apical periodontitis on a single‐rooted tooth or on 1 root with a single canal in a multirooted tooth Exclusion criteria: diagnosis of diabetes, HIV infection or other immunocompromising disease; aged < 16 or > 80 years; teeth with two‐thirds of the root canal treated before enrolment Group 1: 45 teeth Group 2: 26 teeth Group 3: 31 teeth |
|
| Interventions | Group 1: single visit Group 2 (groups 2 and 3 pooled): multiple visits without any dressing or using CH (the instrumentation was completed at the first appointment and, the treatment was completed after 1 week) 1 operator, 9 observers (4 graduate oral and maxillofacial radiology residents, 2 graduate endodontic residents, 1 oral epidemiologist, 1 general dentist, 1 experienced endodontist) to evaluated radiographs using the PAI scoring system. Rubber dam isolation used. Use of magnification loupes and canal shaping not specified in a satisfactory way. Irrigation with 2.5% NaOCl. Working length evaluated by Rx, obturation with gutta‐percha and Roth 801 sealer in lateral condensation |
|
| Outcomes |
Follow‐up 52 weeks. The criteria for success or failure were the following: success (PAI 1 or 2), failure (PAI 3, 4 and 5). |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The patients were assigned to a treatment group by the throwing of a dice". |
| Allocation concealment (selection bias) | Low risk | Quote: "The patients were assigned to a treatment group by the throwing of a dice". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "The 9 observers that participated in the study (…) were all blinded to the treatment groups and aims of the study". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 100% of participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | Low risk | Comment: planned outcomes reported. |
| Other bias | High risk | Comment: it is not explicitly stated that participants with > 1 tooth needing treatment were randomised the same number of times. |
Wang 2010.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical study Country: China Number of centres: 1, Endodontic Centre, West China Dental Hospital Sichuan University, China Setting: hospital dental clinic Recruitment period: 3 years Founding source: not reported |
|
| Participants | Number of participants: 100 enrolled, 89 analysed Number of teeth: 89 Demographics (e.g. sex, age, ethnic group): 56 F, 44 M; aged 20–60 years Inclusion criteria: aged > 18 years with vital single‐rooted teeth with preoperative vital pulps. 1 tooth only for each participant Exclusion criteria: pregnancy, receiving antibiotics or corticosteroids at the time of treatment, immunocompromised, complicating systemic disease, aged < 18 years; tooth with periodontal disease or periapical pathosis. Diagnostic criteria for pulpal vitality based on electric pulp tester and thermal test. Vitality of pulps was confirmed by direct clinical observation of haemorrhage in the canal. All teeth had completely formed foramina and no calcified canals, evaluated with preoperative radiography. Group 1: randomised 50 participants, analysed 43 Group 2: randomised 50 participants, analysed 46 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2 appointments, the second 1 week after first). Intermedication with CH paste, a sterile dry cotton pellet and 3.0 mm of Caviton 2 experienced operators. Rubber dam isolation or use of magnification loupes not reported. Canal shaping: combination of hand files and ProTaper engine‐driven rotary nickel titanium files. Irrigation using 2.5% NaOCl. Working length verified using Root ZX II apex locator. Obturation: ProTaper universal gutta‐percha and AH plus sealer, using a lateral compaction technique. |
|
| Outcomes |
Verbal descriptor scale: preoperative and postoperative at 6, 24 and 48 hours and 1 week after the treatment. Pain categorised as no pain, slight pain, moderate pain, strong pain, severe pain, maximum pain
|
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Patients were randomly assigned to either one‐or two‐visit treatment by biased coin randomisation, a dynamic randomisation method, which was specially design to get the same number in both groups and the sequence …". |
| Allocation concealment (selection bias) | Low risk | Quote: "… tossing coin and allocation were operated by someone who was a graduate student and was not aware of the nature of the study". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 11/100 (11%) of participants were excluded from the study. 11 participants (7 from group 1 and 4 from group 2) were excluded from the analysis: 7 (5 from group 1 and 2 from group 2) did not attend the recall visits, 2 (1 from group 1 and 1 from group 2) failed to return the forms used to monitor postobturation pain, and 2 (1 from group 1 and 1 from group 2) had > 1 root canal. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Wang 2016.
| Study characteristics | ||
| Methods | Study design: 2‐arm, parallel‐group clinical trial Country: China Number of centres: 1, Dangyang Dezhong Dental Hospital Settings: hospital dental clinic Recruitment period: April 2015 to April 2016 Funding source: not reported |
|
| Participants | Number of participants: 120 Number of teeth: 120 Demographics (e.g. sex, age, ethnic group): group 1: 24 F, 36 M; age 32–52 years; mean age 42.1 (SD 3.1) years; group 2: 22 F, 38 M; aged 33–51 years; mean age 44.0 (SD 3.5) years Pulp status: vital teeth Inclusion criteria: not reported Exclusion criteria: not reported Diagnostic criteria: not reported Randomisation: yes, randomisation method not reported Group 1: randomised 60, analysed 60 Group 2: randomised 60 analysed 60 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2). In the first visit, the shaped canal were dressed with CH and temporary sealed with ZOE. Then the participants were visited once a week until the tooth was considered suitable for obturation. Number of operators not reported. Rubber dam isolation. Use of magnification not reported. Irrigation using 5% NaOCl activated with ultrasonics. Working length measure not described. Shaping with Protaper. Canal obturation with gutta‐percha and sealer with hot vertical condensation technique. |
|
| Outcomes |
|
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Allocation concealment (selection bias) | Unclear risk | Comment: insufficient information to permit judgement. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: insufficient information to permit judgement. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: no participants lost to follow‐up reported. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias found. |
Weiger 2000.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Germany Number of centres: 1, Department of Conservative Dentistry, University of Tubingen, Germany Setting; university dental clinic Recruitment period: duration of the study 5 years Funding source: not reported |
|
| Participants | Number of participants: 73 recruited, 67 entered final analysis Number of teeth: 67 Demographics (e.g. sex, age, ethnic group): 37 F, 30 M; mean age 38 years; age range 11–84 years Inclusion criteria: teeth with periapical lesion radiographically demonstrated and where the vitality test was negative; in each participant, only 1 tooth was selected Exclusion criteria: teeth having pockets communicated with the lesion, teeth treated previously, received antibiotics 4 weeks prior to treatment Diagnostic criteria for pulpally or periapical disease: Rx and vitality test Group 1: randomised not reported, analysed 36 Group 2: randomised not reported, analysed 31 |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2). Interappointment medication used was CH mixed with sterile physiological saline that was left in the canals for 7–47 days. Cavity access filled by a temporary cement. 2 operators (experienced endodontists). Use of rubber dam isolation. Use of magnification loupes not reported. Canal shaping: K‐ files and Gates Glidden used in step‐back technique. Irrigation using 1% NaOCl. Working length determined by Rx. Obturation using gutta‐percha with Sealapex in lateral condensation |
|
| Outcomes |
Follow‐up 5 years. Criteria for success or failure were the following in the paper: complete healing, incomplete healing and no healing. The radiographs were judged by both dentists involved in study using a magnifying glass and a light box. The operators did not know whether the tooth belonged to the 1‐visit or the 2‐visit group. In case of disagreement, a joint decision was made. We considered only 2 categories: success (complete healing) and failure (incomplete healing and no healing). |
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The allocation of the tooth modality followed the method of minimization to balance the two groups of teeth with regard to the criterion tooth type". |
| Allocation concealment (selection bias) | Unclear risk | Comment: not reported. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "The radiographs were judged by both dentists involved in the study, the operators did not know whether the tooth belonged to the one‐visit or the two‐visits group". |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 91.7% of participants who entered the study were included in the final analysis. 6 participants lost at follow‐up (5 did not return at recall appointments, 1 deceased prior to first scheduled recall rate). |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Wong 2015.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: China Number of centres: 1, Health Service Dental Clinic of the University of Hong Kong Setting; university dental clinic Recruitment period: 30 months Funding source: not reported |
|
| Participants | Number of participants: 228 participants: 115 in group 1 and 113 in group 2. 194 participants with 220 teeth entered final analysis Number of teeth: 256 teeth Demographics (e.g. sex, age, ethnic group): 135 F, 85 M; mean age 46.4 (SD 14.1) years Inclusion criteria: no history of periodontitis, tooth that required primary endodontic treatment was periodontally healthy and at least half of the coronal structure had to be remaining Exclusion criteria: teeth with pulpotomy, participants who had severe acute pulpitis with facial swelling or systemic infection, severe systemic disease, increased stress on the temporomandibular joint musculature or increased psychological stress Group 1: randomised 128 teeth from 115 participants, analysed 117 teeth from 105 participants Group 2: randomised 128 teeth from 113 participants, analysed 103 teeth from 89 participants |
|
| Interventions | 2 general dentists carried out the endodontic treatments. Rubber dam isolation. 1 operator was trained to use a magnifying loupe (×2.5). The 2 dentists received a calibration workshop prior to this clinical trial to standardise the instrumentation and obturation technique. The root canals were cleaned and shaped using NiTi rotary files. 5.25% NaOCl used for irrigation. Temporary restoration made using a resin‐modified ZOE cement until obturation. All teeth were obturated using a core‐carrier technique. Total chairside time recorded by the dental assistant. Treated teeth were restored with silver amalgam or composite resin. All participants were reviewed 1 week after obturation, and were advised to have indirect extracoronal restoration (partial or full veneer) to avoid failure due to extracoronal leakage or tooth fracture. Group 1: single visit Group 2: multiple visits (2 or 3; depending on the complexity of the treatment, the second was scheduled 1 week after the first). A non‐setting 5% CH paste was used as interappointment medication. |
|
| Outcomes |
Success was graded as no clinical signs/symptoms and no radiographic radiolucency found in the periapical radiograph.
|
|
| Notes | Trial registered in the Chinese Clinical Trial Registry of the World Health Organization (ChiCTR‐IOR‐15006117). Data for number of sinus track were reported with the number of abscess; therefore, could not be extracted. |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The treated teeth were randomly assigned to either single‐visit or multi‐visit treatments using the random‐number generating function of a calculator". |
| Allocation concealment (selection bias) | Low risk | Quote: "patients were randomly assigned by the receptionist for endodontic treatment". |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "A number unknown to the operators and the independent assessor was given to each treated tooth for clinical and radiographic assessment, data entry and analysis". |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Comment: 36 teeth (15%) from 34 participants (14%) were lost at follow‐up. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
Yoldas 2004.
| Study characteristics | ||
| Methods | Study design: randomised parallel‐group clinical trial Country: Turkey Number of centres: 1. Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, University of Cukurova, Turkey Setting: hospital dental clinic Recruitment period: 2 years Funding source: not reported |
|
| Participants | Number of participants: 227 enrolled, 218 analysed Number of teeth: 218 Demographics (e.g. sex, age, ethnic group): aged > 18 years; sex and ethnicity not reported Inclusion criteria: teeth with inadequate root canal filling Exclusion criteria: complicating systemic disease, severe pain or acute apical abscess or both, aged < 18 years, use of antibiotics or corticosteroids, multiple teeth requiring retreatment, root canals that could not be treated well with initial RoCT Diagnostic criteria for pulpal or periapical disease: evaluation of periapical status with Rx evaluated by 1 author according to PAI Group 1: randomised 115, analysed 106 Group 2: randomised 112, analysed 112 9 participants (7 from group 1 and 2 from group 2) were excluded from the study because they did not participate in recall visits. |
|
| Interventions | Group 1: single visit Group 2: multiple visits (2; second appointment 7 days after the first). The canals in the interappointment period were medicated with CH‐CHX paste and closed with a sterile dry cotton pellet and a temporary restorative material (Cavit) for 7 days. 3 operators. Rubber dam isolation. Use of magnification loupes not reported. Canal shaping with Gates Glidden, hand files NiTi rotary instruments with step‐back technique. Irrigation using 2.5% NaOCl. Working length determined by apexes locator and periapical radiograph. Obturation using gutta‐percha and AH‐26 sealer with lateral condensation |
|
| Outcomes |
1 week after initial appointment the participants were recalled and asked about the occurrence of postoperative pain). Level of discomfort rated as: no pain, mild pain, moderate pain, severe pain. We considered only 2 categories: no pain, pain (mild, moderate, severe).
Participants with severe postoperative pain or occurrence of swelling or both (see Table 3)
|
|
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quote: "randomisation of assignment into the treatment groups was made by 1 author according to the PAI, the tooth type and patient symptoms". |
| Allocation concealment (selection bias) | High risk | Comment: assignment by 1 of the study authors. |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Comment: not applicable, radiographic assessment was not among outcomes. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 218/227 (96%) of participants who entered the study were included in the final analysis. |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes reported as planned. |
| Other bias | Low risk | Comment: no other source of bias identified. |
AH‐26 and AH‐Plus: root canal filling and sealer materials; AP: apical periodontitis; CBCT: cone‐beam computed tomography; CH: calcium hydroxide; CHX: chlorhexidine; EAL: electronic apex locator; EDTA: ethylene‐diamine‐tetraacetic acid; F: female; ISO: International Organization for Standardization; M: male; min: minute; NaOCl: sodium hypochlorite; NiTi: nickel–titanium; NRS: numerical rating scale; PAI: periapical index; RC‐Prep: chemomechanical preparation for root canals; RC‐Help: lubricating paste for root canals; RoCT: root canal treatment; Root‐ZX: apex locator; Rx: radiological evaluation; s: second; SD: standard deviation; VAS: visual analogue scale; ZOE: zinc oxide eugenol; ZnO: zinc oxide.
Characteristics of excluded studies [ordered by study ID]
| Study | Reason for exclusion |
|---|---|
| Albashaireh 1998 | Treatment protocol did not mention use of rubber dam. |
| Cai 2016 | Treatment protocol did not mention use of rubber dam. |
| Chang 2018 | Treatment protocol mentioned neither use of rubber dam nor of hypochlorite as irrigant. |
| Chen 2016 | Treatment protocol did not mention use of rubber dam. |
| Dai 2015 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Darvesh 2020 | Treatment protocol did not mention use of rubber dam. |
| Fava 1994 | Study design unclear. We sent an e‐mail to study authors asking for more details about their randomisation method but we did not consider the answer satisfactory or the study randomised or quasi‐randomised. |
| Ghoddusi 2006 | Use of sodium hypochloride not reported. |
| Hua 2009 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Ji 2017 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Ji 2020 | Treatment protocol did not mention use of rubber dam. |
| Kvist 2004 | Study did not include any of the outcomes considered in the review. |
| Li 2016 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Liu 2020 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Mariyamu 2016 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Naseri 2019 | Abstract only; it was not possible to obtain the full publication of the study. |
| Oginni 2004 | Use of rubber dam not reported. |
| Qin 2011 | Study did not include any of the outcomes considered in this review. |
| Shen 2018 | Study not randomised or quasi‐randomised. |
| Soltanoff 1978 | Use of rubber dam and sodium hypochlorite not reported. |
| Tan 2014 | Treatment protocol did not mention use of rubber dam. |
| Wang 2014 | Study not randomised or quasi‐randomised. |
| Wang 2018 | Study did not include any of the outcomes considered in this review. |
| Wei 2017 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Wu 2016 | Treatment protocol did not mention use of rubber dam. |
| Xiao 2010 | Use of rubber dam not reported. |
| Xie 2010 | Study did not include any of the outcomes considered in this review. |
| Xu 2017 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Xue 2018 | Study did not include any of the outcomes considered in this review. |
| Yang 2016 | Study did not include any of the outcomes considered in this review. |
| Yang 2019 | Study not randomised or quasi‐randomised. |
| Ye 2016 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Yi 2016 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| You 2014 | Study not randomised or quasi‐randomised. |
| Yuan 2019 | Treatment protocol did not mention use of rubber dam. |
| Yue 2017 | Study not randomised or quasi‐randomised. |
| Zhang 2014 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Zhang 2016 | Treatment protocol mentioned neither use of rubber dam nor use of hypochlorite as irrigant. |
| Zhanghuan 2014 | Study included children with primary teeth. |
| Zhen 2018 | Study not randomised or quasi‐randomised. |
| Zou 2012 | Treatment protocol did not mention use of rubber dam. |
RoCT: root canal treatment.
Differences between protocol and review
The review was slightly modified from the last version of the review.
Inclusion criteria: in addition to the already applied inclusion/exclusion criteria, in this version we included only studies in which root canal treatment was carried out following the current standard of care (rubber dam isolation, use of sodium hypochlorite as irrigant). This modification led to the exclusion of five studies previously included (Albashaireh 1998; Ghoddusi 2006; Oginni 2004; Soltanoff 1978; Xiao 2010).
Outcomes: in this update, we considered post‐treatment pain within one week (calculated from the single‐visit treatment or the first session of multiple‐visit treatment). We removed the secondary outcome 'any complication' since data from studies did not allow us to correctly calculate it.
Contributions of authors
GM: main review author, participation in all phases of the review's preparation.
MGan: participation in all phases of the review's preparation.
GL: group co‐ordinator, contributor in all phases of the review's preparation, article retrieval, data collection, interpretation of results.
LF: manuscript preparation, interpretation of results.
MGag: manuscript preparation, interpretation of results.
MM: contributor in all phases of the review's preparation, article retrieval, data collection, interpretation of results.
Sources of support
Internal sources
-
Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK, UK
Support to Cochrane Oral Health
-
Manchester Academic Health Sciences Centre (MAHSC) and the NIHR Manchester Biomedical Research Centre, UK, UK
Support to Cochrane Oral Health
External sources
-
National Institute for Health Research (NIHR), UK
This project was supported by the NIHR, via Cochrane Infrastructure funding to Cochrane Oral Health. The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Evidence Synthesis Programme, the NIHR, the National Health Service or the Department of Health and Social Care.
-
Cochrane Oral Health Global Alliance, Other
The production of Cochrane Oral Health reviews has been supported financially by our Global Alliance since 2011 (ohg.cochrane.org/partnerships-alliances). Contributors over recent years have been: British Association for the Study of Community Dentistry, UK; British Society of Paediatric Dentistry, UK; the Canadian Dental Hygienists Association, Canada; Centre for Dental Education and Research at All India Institute of Medical Sciences, India; National Center for Dental Hygiene Research & Practice, USA; New York University College of Dentistry, USA; NHS Education for Scotland, UK; Swiss Society for Endodontology, Switzerland.
Declarations of interest
GM: none.
MGan: none.
GL: none known. I am an Editor with Cochrane Oral Health but was not involved in the editorial process for this review.
LF: none.
MGag: none.
MM: none.
Edited (no change to conclusions)
References
References to studies included in this review
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