Interventions for increasing acceptance of local anaesthetic in children and adolescents having dental treatment

Joana Monteiro; Ajit Tanday; Paul F Ashley; Susan Parekh; Hamdan Alamri

doi:10.1002/14651858.CD011024.pub2

. 2020 Feb 27;2020(2):CD011024. doi: 10.1002/14651858.CD011024.pub2

Interventions for increasing acceptance of local anaesthetic in children and adolescents having dental treatment

Joana Monteiro ^1,^✉, Ajit Tanday ¹, Paul F Ashley ¹, Susan Parekh ¹, Hamdan Alamri ^2,³

Editor: Cochrane Oral Health Group

PMCID: PMC7045283 PMID: 32104910

Abstract

Background

Delivery of pain‐free dentistry is crucial for reducing fear and anxiety, completion of treatment, and increasing acceptance of future dental treatment in children. Local anaesthetic (LA) facilitates this pain‐free approach but it remains challenging. A number of interventions to help children cope with delivery of LA have been described, with no consensus on the best method to increase its acceptance.

Objectives

To evaluate the effects of methods for acceptance of LA in children and adolescents during dental treatment.

Search methods

Cochrane Oral Health's Information Specialist searched the Cochrane Oral Health's Trials Register (to 24 May 2019); the Cochrane Central Register of Controlled Trials (CENTRAL; 2019 Issue 4) in the Cochrane Library (searched 24 May 2019); MEDLINE Ovid (1946 to 24 of May 2019); Embase Ovid (1980 to 24 May 2019); and Web of Science (1900 to 24 May 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and World Health Organization International Clinical Trials Registry Platform were also searched to 24 May 2019. There were no restrictions on language or date of publications.

Selection criteria

Parallel randomised controlled trials (RCTs) of interventions used to increase acceptance of dental LA in children and adolescents under the age of 18 years.

Data collection and analysis

We used standard methodological procedures expected by Cochrane. We performed data extraction and assessment of risk of bias independently and in duplicate. We contacted authors for missing information. We assessed the certainty of the body of evidence using GRADE.

Main results

We included 26 trials with 2435 randomised participants aged between 2 and 16 years. Studies were carried out between 2002 and 2019 in dental clinics in the UK, USA, the Netherlands, Iran, India, France, Egypt, Saudi Arabia, Syria, Mexico, and Korea. Studies included equipment interventions (using several LA delivery devices for injection or audiovisual aids used immediately prior to or during LA delivery or both) and dentist interventions (psychological behaviour interventions delivered in advance of LA (video modelling), or immediately prior to or during delivery of LA or both (hypnosis, counter‐stimulation).

We judged one study to be at low risk and the rest at high risk of bias. Clinical heterogeneity of the included studies rendered it impossible to pool data into meta‐analyses. None of the studies reported on our primary outcome of acceptance of LA. No studies reported on the following secondary outcomes: completion of dental treatment, successful LA/painless treatment, patient satisfaction, parent satisfaction, and adverse events.

Audiovisual distraction compared to conventional treatment: the evidence was uncertain for the outcome pain‐related behaviour during delivery of LA with a reduction in negative behaviour when 3D video glasses where used in the audiovisual distraction group (risk ratio (RR) 0.13, 95% confidence interval (CI) 0.03 to 0.50; 1 trial, 60 participants; very low‐certainty evidence).

The wand versus conventional treatment: the evidence was uncertain regarding the effect of the wand on pain‐related behaviour during delivery of LA. Four studies reported a benefit in using the wand while the remaining studies results suggested no difference between the two methods of delivering LA (six trials, 704 participants; very low‐certainty evidence).

Counter‐stimulation/distraction versus conventional treatment: the evidence was uncertain for the outcome pain experience during delivery of LA with children experiencing less pain when counter‐stimulation was used (RR 0.12, 95% CI 0.04 to 0.34; 1 trial, 134 participants; very low‐certainty evidence).

Hypnosis versus conventional treatment: the evidence was uncertain for the outcome pain experience during delivery of LA with participants in the hypnosis group experiencing less pain (mean difference (MD) ‐1.79, 95% CI ‐3.01 to ‐0.57; 1 trial, 29 participants; very low‐certainty evidence).

Other comparisons considered included pre‐cooling of the injection site, the wand versus Sleeper One, the use of a camouflage syringe, use of an electrical counter‐stimulation device, and video modelling acclimatisation, and had a single study each. The findings from these other comparisons were insufficient to draw any affirmative conclusions about their effectiveness, and were considered to be very low‐certainty evidence.

Authors' conclusions

We did not find sufficient evidence to draw firm conclusions as to the best interventions to increase acceptance of LA in children due to variation in methodology and nature/timing of outcome measures. We recommend further parallel RCTs, reported in line with the CONSORT Statement. Care should be taken when choosing outcome measures.

Plain language summary

Interventions to facilitate delivery of local anaesthetic in children and adolescents during dental treatment

Review question

With this Cochrane Review we tried to find out the best way to get children to accept receiving an injection of local anaesthetic during dental treatment.

Background

It is important that children and adolescents receive dental treatment without pain so they have less anxiety and fear. It will also help them accept treatment in the future. Giving local anaesthetic, medication that temporarily stops the sense of pain in one small area of the body while the child stays awake and alert, will help to achieve this. However, it is not always easy to give children local anaesthetic. Some children do not cope well with the injection. There are a number of interventions that may help children accept dental local anaesthetic, however, there is no agreement over which is the best method.

Study characteristics

This review is up‐to‐date as of 24 May 2019. We included 26 studies with a total of 2435 children aged between 2 and 16 years. The studies were carried out between 2002 and 2019 in dental clinics in the UK, USA, the Netherlands, Iran, India, France, Egypt, Saudi Arabia, Syria, Mexico, and Korea.

We included studies comparing the use of different equipment like audiovisual glasses or a computerised device for injection called the wand, or dentist interventions like hypnosis, counter‐stimulation/distraction, video modelling, to increase the acceptance of delivery of local anaesthetic. These interventions were compared against delivery of local anaesthetic using a conventional syringe (usual care), or any other dental equipment or dentist intervention. Interventions were given just before the injection and others were given just before, during the injection, and continued during the dental treatment.

Key results

The evidence was uncertain for audiovisual distraction (using 3D video glasses as distraction) compared to conventional treatment. The evidence was uncertain when comparing the wand to conventional treatment. The evidence was also uncertain for counter‐stimulation/distraction compared to conventional treatment and for hypnosis compared to conventional treatment.

Other comparisons considered included pre‐cooling of the injection site, the wand versus another electronic system called Sleeper One, the use of a camouflage syringe, use of an electrical counter‐stimulation device, and video modelling. They had a single study each. The findings from these other comparisons were not enough to be able to decide on their effectiveness.

The included studies did not mention if there were any harmful effects of the different interventions.

Certainty of the evidence

The level of belief we have in these findings is very low. This was due to high risk of bias and the small number of people studied in the included trials.

Conclusion

We do not have enough evidence to say which intervention works better to increase acceptance of local anaesthetic in children and adolescents. We suggest that more well‐conducted studies should be done in this area.

Summary of findings

Background

Dental caries remains a serious problem in children, affecting 23.3% of five‐year olds in England and 27.9% of two‐ to five‐year olds in the USA (Dye 2007; PHE 2017). If untreated, caries may lead to pain, infection, malnutrition, and disturbed growth (Acs 1999; Low 1999). Social and financial consequences may include days off school or work, referral to specialised care and general anaesthetic resulting in increased costs (Thikkurissy 2010). Surgical approaches and new preventive strategies have been developed and widely researched (Innes 2015; Kandiah 2010). Once dentinal caries is established, restorative or surgical treatment is needed, traditionally requiring local anaesthetic (LA).

Description of the condition

Dental anxiety is a well‐known barrier to treatment, commonly developing during childhood or adolescence (Locker 1999). Early onset of dental anxiety may have significant consequences, being associated with behavioural problems that may lead to increased pain perception and interference with the treatment provided (Ayer 2005; Klingberg 1995; van Wijk 2008). Ultimately, children's dental anxiety may lead to avoidance of treatment and irregular attendance in adulthood (Skaret 2003).

The aetiology of dental anxiety is multifactorial. Children's cognitive abilities, parental anxiety and previous negative dental or medical experiences seem to play a crucial role in the development of dental anxiety (Townend 2000; Versloot 2008a). Invasive procedures, injections and drilling in particular, appear to be the most anxiety‐inducing treatments in children (Majstorovic 2004).

Dental injection phobia is a subtype of blood‐injury‐injection phobia. Milgrom considers general fear of injections, including pain and fear of injury, to be the main aspects of dental injection fear (Milgrom 1997). In children, needle phobia was found to be significant, with a prevalence of 19% in four‐ to six‐year olds. Fear of needles seems to decrease with age, possibly due to cognitive maturation or development of coping behaviours (Majstorovic 2004). Nevertheless, prevalences of 11% of 10‐ to 11‐year olds and 11% of 18‐year olds shows the significant importance of fear of intraoral injections (Majstorovic 2004; Vika 2008). Furthermore, authors have found a strong relationship between blood‐injury‐injection phobia and dental anxiety (Vika 2008). Additionally, dental anxiety and pain of injection seem to be strongly correlated, with highly anxious patients reporting increased pain perception and duration (van Wijk 2008). Weisman showed that inadequate analgesia for invasive medical procedures in young children may reduce the effect of appropriate analgesia in the future (Weisman 1998). Similarly, it appears that previous experiences with dental injections may lead to behavioural problems in subsequent treatment sessions (Versloot 2008a).

Delivery of pain‐free dentistry is crucial for reducing fear and anxiety, facilitating delivery of treatment, developing a trusting dentist/patient relationship, and accepting future treatment. Delivery of LA is a vital part of this, however it remains one of the most challenging aspects of paediatric dentistry.

Description of the intervention

Delivery of high‐quality dentistry to children is closely linked to a non‐threatening approach and pain‐free treatment. A number of behaviour management techniques have been proposed and are consistently applied during treatment, in order to achieve successful outcomes (Ashley 2015; Ashley 2018; Campbell 2011). Delivery and acceptance of dental LA is one of the most trying aspects of treatment. In order to facilitate this, several specific techniques and materials have been developed and researched. This Cochrane Review focused on interventions specifically used for delivery of LA. The use of other behaviour management techniques is implied during all steps of dental treatment. Although these may indirectly influence acceptance of LA, they were not specifically discussed in this review.

In general terms, interventions were considered successful when treatment was completed or anxiety and pain reduced in comparison to control groups. These interventions are aimed at increasing acceptance of LA, often with completion of the proposed dental treatment as an end result. In other studies, authors undertook assessments of children's pain and anxiety by using physiological assessment questionnaires or interviews, anxiety scales, and behavioural assessment (Peretz 2000; Sixou 2009).

Meechan described three factors that influence discomfort during delivery of LA: factors related to the patient, equipment factors, and aspects that are under control of the dentist (Meechan 2009). The two latter were the focus of this review.

Patient factors

As previously discussed, dental anxiety seems to have a multifactorial aetiology, being closely related to child psychological factors (ten Berge 1999). The level of generalised anxiety and psychological function seem to be determinant factors in children's dental anxiety (Krikken 2010; Versloot 2008a). This may, in turn, influence children's acceptance of dental treatment, including delivery of LA.

Equipment factors

Equipment factors include interventions delivered immediately prior to and during LA as well as LA delivery devices (where the intervention is injection) and materials, such as topical LA.

The use of visual or auditory technology has been suggested as a distraction technique in order to reduce anxiety and pain perception during delivery of dental treatment (including LA) for children.

Aitken 2002; Baghdadi 2000a; Marwah 2005; and Prabhakar 2007 studied the effect of music distraction on anxiety, pain, or behaviour for children undergoing dental treatment with LA. Similarly, the use of videos either prior to or during treatment (including audiovisual glasses) has been studied as a possible distraction technique by Hoge 2012; Ingersoll 1984; Melamed 1975a; and Ram 2010. These were used independently or in conjunction with pharmacological behaviour management techniques.

Although topical anaesthetic is commonly used, controversy remains on its efficacy in reducing pain of dental injections in children (Berg 2007; Deepika 2012; Kreider 2001; Nayak 2006; Paschos 2006; Primosch 2001; Tulga 1999). Similarly, Aminabadi 2009a studied the effect of pre‐cooling the injection site, followed by topical anaesthetic, for delivery of LA. The gauge or length of the needle (Brownbill 1987; Ram 2007) and the temperature of the cartridge (Ram 2002a) have equally been investigated for their influence on pain perception and anxiety of children during delivery of LA.

In recent years, several electronic delivery devices for LA have been developed, that promote distraction by vibration, needleless injections, or transcutaneous electrical nerve stimulation.

The influence of electronic devices for infiltration or intraligamental anaesthesia on children's anxiety and pain has been investigated by a number of authors (Baghdadi 2000a; Hembrecht 2013; Kuscu 2008; Nieuwenhuizen 2013; Palm 2004; Ram 2006a; Tahmassebi 2009; Versloot 2005; Versloot 2008a; Wilson 1999). Sixou 2008 studied treatment success rates following LA with an electronic device for intraosseous LA. In 2009, the same author assessed children's pain perception using this device (Sixou 2009). Roeber evaluated the effects of using a vibrating attachment to the syringe for LA in children (Roeber 2011). Arapostathis compared acceptance, preference and efficacy of a needleless injection device to conventional syringes in children (Arapostathis 2010). Similarly, transcutaneous nerve stimulation was studied as an alternative to conventional LA in children (Harvey 1995; Munshi 2000; Oztaş 1997).

Dentist factors

Non‐pharmacological interventions

Non‐pharmacological interventions have been suggested in order to increase acceptance of LA. These methods may include verbal distraction by the dentist, the use of non‐threatening words (or 'childrenese') to describe dental injections (Fayle 1997), imagery suggestion, systematic desensitisation, or counter‐stimulation during LA. These interventions may be delivered in advance of LA or immediately prior to and during LA.

A number of case reports and review articles have focused on systematic desensitisation for dental treatment in children. Several randomised controlled trials have been undertaken in adults but there is a paucity of studies in children (Levitt 2000). A distraction technique involving repeated breathing in and blowing out air was studied as an alternative distraction for children receiving dental LA (Peretz 1999). The same author studied the benefits of imagery suggestion during delivery of LA for children's dental treatment. This technique involves selection of a pleasant image in which the child is asked to concentrate during treatment (Peretz 2000). Other authors studied the influence of counter‐stimulation and distraction on pain perception of children during delivery of LA (Aminabadi 2008).

Hypnosis has been used and researched for delivery of treatment and LA (Al‐Harasi 2010; Huet 2011). Viewing/hiding the needle prior to injection has also been subject of research (Maragakis 2006). Several authors found that the time taken to deliver LA has an influence on injection pain (Jones 1995; Maragakis 1996). Similarly, the site of injection may influence pain perception and anxiety, hence certain authors suggesting adoption of treatment sequences that contemplate these parameters (Aminabadi 2009b).

Pharmacological interventions

Ultimately, pharmacological techniques such as inhalation, oral, intranasal or intravenous sedation have been widely used as adjuvants to delivery and acceptance of LA. A recent Cochrane Review investigated the efficacy of conscious sedation for paediatric dental treatment (Ashley 2018). The authors found weak and very weak evidence supporting the effectiveness of oral midazolam and nitrous oxide, respectively.

Pharmacological interventions were not the focus of this review and for that reason studies where sedation was used to increase acceptance of LA were not included. The inclusion criteria included studies where standardised sedation was equally used in all arms of the studies (except if sedation was the intervention).

How the intervention might work

Provision of pain and anxiety‐free LA is of utmost importance. A number of interventions to help children cope with delivery of LA have been discussed in the literature.

A common aim of interventions is to reduce pain and anxiety during injection. Some pre‐treatment reviews have shown that children need time to rehearse their coping strategies. Other interventions are given just prior to the injection and others are given just prior to, during the injection, and continue onwards during the dental treatment.

Equipment factors may work differently in order to reduce anxiety and enable LA delivery: music and audiovisual technologies aim to redirect the child's attention away from the procedure. Furthermore, it has been suggested that music provides comfort and induces relaxation at a neurological level (Bradt 2013). The use of topical anaesthetic, the influence of the gauge of the needle, site/order of injection and time taken to deliver LA are all factors that have implications on pain perception during injection (Meechan 2009). One may argue that an additional benefit of topical anaesthetic may be reassurance of using an anaesthetic agent prior to injection. The use of electronic injection devices, similarly, may influence pain perception during delivery of LA. These devices may also benefit from a different appearance to traditional syringes, possibly increasing children's acceptance (Kuscu 2008). Clinician's factors as counter‐stimulation, breathing techniques or imagery suggestion may act as distraction methods. The latter two also aim to induce relaxation (Peretz 2000). Similarly, systematic desensitisation aims to promote a relaxed state, while exposing children to fear‐inducing stimuli (Levitt 2000). Finally hypnosis will work very similarly by redirecting children's attention away from the procedure while influencing their feelings, perception, and behaviour (Al‐Harasi 2010).

The type of surgical procedure may be a factor influencing the overall anxiety of the child, including during LA delivery.

Short‐term benefits of successful interventions include successful delivery of LA and completion of dental treatment. This would occur at the current or at subsequent appointments or both, ultimately leading to restoration of oral health. The long‐term benefit may involve reduction of dental anxiety, leading to acceptance of future treatment and development of positive attitudes towards oral health.

Why it is important to do this review

Local anaesthetic is still required for a number of procedures in paediatric dentistry. There is, however, no consensus on what is the best intervention to increase its acceptance.

Several authors looked at interventions for increasing children's acceptance to invasive medical treatment. One Cochrane Review looked at psychological interventions for non‐dental needle‐related procedural pain and distress in children and adolescents. This review focused on cognitive techniques, behavioural interventions, and combined (cognitive‐behavioural) interventions. The authors concluded that psychological interventions, especially distraction, hypnosis, and combined cognitive‐behavioural interventions can be successful (Uman 2013). Similarly, another Cochrane Review looking at interventions to assist induction of general anaesthesia in children, studied psychological interventions, environmental interventions, equipment modification, social interventions, and anaesthetic communication. The authors felt that non‐pharmacological interventions such as acupuncture, clowns/clown doctors, playing videos of the child's choice, low sensory stimulation, and hand‐held video games need further investigation in reducing anxiety and improving co‐operation (Manyande 2015).

A number of studies and reviews have researched the effect of interventions to reduce preoperative anxiety in adults. Bradt looked at music interventions and concluded that listening to music may have a beneficial effect on preoperative anxiety (Bradt 2013). Adult studies interestingly include alternative therapies as acupuncture for reducing anxiety prior to dental treatment (Michalek‐Sauberer 2012). This technique has been researched in children for reduction of gag reflex during impressions for orthodontic treatment, however, the authors are not aware of any published studies on its use for increasing acceptance of LA (Sari 2010).

To our knowledge, there are no comprehensive systematic reviews on interventions to facilitate delivery of dental LA in children and adolescents. Although certain interventions have shown to be successful, controversy remains regarding a number of techniques, leading to confusion and empiric application in clinical settings.

We felt that reviewing the available evidence would further our understanding of existing techniques, as well as determine whether further research on this topic was warranted.

Objectives

To evaluate the effects of methods for acceptance of local anaesthetic in children and adolescents during dental treatment.

Methods

Criteria for considering studies for this review

Types of studies

We included parallel randomised controlled trials. We excluded quasi‐randomised and cross‐over trials.

Types of participants

Children and adolescents up to 18 years old having dental treatment under local anaesthetic (LA) without general anaesthesia. Studies that included participants over the age of 18 were not included in this review, to ensure our search was limited to children. If studies included both children and participants over 18 years old, they were excluded, unless authors clearly provided separate data for children. Children and adolescents (up to 18 years) with any form of special healthcare needs were not excluded from this review.

Types of interventions

Classification of interventions is complex and often overlapping, as there is no standard definition in the literature. We decided to adapt Meechan's factors for discomfort of LA and included interventions based on studies referred to in our background.

We included studies comparing the use of dental equipment or dentist‐led intervention to increase the acceptance of delivery of LA in children and adolescents against delivery of LA using a conventional syringe (usual care), or any other dental equipment or dentist‐led intervention.

Meechan's patient's factors (for example: the level of generalised anxiety and psychological function) were excluded, as interventions often require a multidisciplinary and lengthy approach for which the remit likely extends beyond that of acceptance of LA.

Pharmacological techniques such as oral, inhalation, intranasal and intravenous sedation or general anaesthetic have been subject of a number of trials and systematic reviews, including Cochrane Reviews (e.g. Ashley 2018). For this reason, they were not included in our search criteria. However, if sedation was administered to both study and control groups (hence not the researched intervention), these trials were included in our review.

We, therefore, classified the interventions as follows.

Equipment factors.
- Audiovisual technology.
  - Visual.
  - Auditory.
  - Combined visual and auditory.
- Topical anaesthetic.
  - Topical anaesthetic agents.
  - Cooling of injection site.
- LA.
  - Gauge of needle.
  - Temperature of cartridge.
- Electronic devices.
  - Infiltration devices.
  - Intraosseous devices.
  - Intraligamental devices.
- Other.
  - Needleless devices.
  - Vibration devices.
  - Transcutaneous nerve stimulation.
Dentist factors (non‐pharmacological interventions).
- Imagery suggestion.
- Counter‐stimulation.
- Systematic desensitisation.
- Hypnosis.
- Others.
  - Language ‐ non‐threatening words.
  - Viewing/hiding needle.
  - Time taken to deliver LA.
  - Site of injection/order of treatment.

Our acceptance criteria included studies with interventions that were undertaken:

in advance of delivery of LA (such as video modelling);
immediately before LA (such as hypnosis);
during LA (such as distraction or vibration devices).

When different LA delivery systems were studied the intervention was the injection itself.

This Cochrane Review did not look at types, dosage, or efficacy of LA. Pharmacological behaviour management techniques such as sedation were excluded as interventions.

Studies that combined two or more interventions (other than pharmacological) were included and considered separately to single intervention trials.

Types of outcome measures

Primary outcomes

Acceptance of LA (yes/no).

Secondary outcomes

Completion of dental treatment (yes/no).
Successful LA/painless treatment (yes/no).
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA.
Pain on injection (yes/no).
Pre and postoperative anxiety measures.
Patient satisfaction: measured by questionnaires.
Parent satisfaction: measured by questionnaires.
Adverse events.

Assessment of children's pain and anxiety may be undertaken by one or more methods: physiological assessment (physical signs of anxiety: high pulse rate, release of stress hormones and dry mouth), questionnaires or interviews, anxiety scales (completed by parents or children), and behavioural assessment (direct observation of the child's behaviour or psychological state by researchers).

By including these secondary outcomes, the authors tried to describe the level of discomfort the child expressed prior to and during LA. In secondary and tertiary settings children are often referred after a successful LA, but unable to tolerate further treatment after that. Successful LA enables the operator to complete treatment, for this reason one of the secondary outcomes is completion of dental treatment.

Adverse events related to specific interventions were recorded where appropriate.

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 (RCTs) and controlled clinical trials without language or publication status restrictions:

Cochrane Oral Health's Trials Register (to 24 May 2019) (Appendix 1);
Cochrane Central Register of Controlled Trials (CENTRAL; 2019 Issue 4) in the Cochrane Library (searched 24 May 2019) (Appendix 2);
MEDLINE Ovid (1946 to 24 May 2019) (Appendix 3);
Embase Ovid (1980 to 24 May 2019) (Appendix 4);
Web of Science (1900 to 24 May 2019) (Appendix 5).

Subject strategies were modelled on the search strategy designed for MEDLINE Ovid but revised appropriately for each database. Where appropriate, they were combined with subject strategy adaptations of the highly sensitive search strategy designed by Cochrane for identifying RCTs and controlled clinical trials as described in the Cochrane Handbook for Systematic Reviews of Interventions Chapter 6 (Lefebvre 2011). The search of Embase Ovid was linked to an adapted version of the Cochrane Centralised Search Project filter for identifying RCTs in Embase Ovid (see www.cochranelibrary.com/central/central‐creation for information).

No restrictions were placed on the language or date of publication when searching the electronic databases. Non‐English studies were translated and included in the review.

Searching other resources

Cochrane Oral Health's Information Specialist searched the following registries for ongoing/unpublished trials to 24 May 2019:

the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov; www.clinicaltrials.gov) (Appendix 6);
the World Health Organization International Clinical Trials Registry Platform (www.who.int/trialsearch) (Appendix 7).

We also searched the metaRegister of Controlled Trials on 15 June 2015, but this resource is no longer available (Appendix 8).

We contacted specialists in the field for any unpublished data.

We searched the reference lists of included studies and relevant systematic reviews for further studies.

We checked that none of the included studies in this review were retracted due to error or fraud.

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 independently, and in duplicate, assessed titles and abstracts and full texts for inclusion in the review. The search was designed to be sensitive and include controlled clinical trials, these were filtered out early in the selection process if they were not randomised. Disagreement was resolved by discussion. The search was designed to be sensitive and include controlled clinical trials, these were filtered out early in the selection process if they were not randomised. Those studies which did not meet the inclusion criteria were recorded in the excluded studies section of the review and the reason for exclusion was noted in the Characteristics of excluded studies table.

Data extraction and management

We extracted information relevant to the objectives and outcome measures into a specially designed data extraction form (Appendix 9). Any disagreements were resolved by discussion. Journal or authors' names were masked before selection or extraction. All studies meeting the selection criteria were included. We collected descriptive data where available in addition to those already outlined. These data were used to provide contextual information for the main outcomes thus aiding interpretation of results from this review.

Data collected included.

Year study started (if not available, year it was published).
Country where the study was carried out.
Type of intervention.
Who delivered the intervention.
Who delivered LA.
Who assessed the intervention.
How the intervention was assessed.
Treatment provided.
Previous LA for dental treatment.
Previous treatment of participants.
Setting of intervention/treatment.
Age of the participant.
Gender of the participant.

Assessment of risk of bias in included studies

Risk of bias was assessed using Cochrane's tool for assessing risk of bias as described in Chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (Higgins 2011). We assessed included trials on the following domains as at 'low', 'unclear', or 'high' risk of bias:

random sequence generation,
allocation concealment,
blinding of participants and personnel,
blinding of outcome assessment,
incomplete outcome data,
selective outcome reporting, and
other sources of bias.

We reported these assessments for each individual study in the 'Risk of bias' tables. We also presented the results graphically (Figure 1; Figure 2).

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Within a study, a summary assessment of low risk of bias was given when there was a low risk of bias for all key domains, unclear risk of bias when there was an unclear risk of bias for one or more key domains, and high risk of bias when there was a high risk of bias for one or more key domains. Across studies, a summary assessment was rated as low risk of bias when most information was from studies at low risk of bias, unclear risk of bias when most information was from studies at low or unclear risk of bias, and high risk of bias when the proportion of information was from studies at high risk of bias sufficient to affect the interpretation of the results.

Measures of treatment effect

For dichotomous outcomes such as acceptance of LA we planned to calculate risk ratios along with 95% confidence intervals. Continuous outcomes such as intraoperative distress were reported as mean and standard deviation, to calculate mean differences and 95% confidence intervals.

Unit of analysis issues

The unit of analysis was the participant. We followed the guidance included in Section 16.1.2 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We planned to adjust data derived from cluster‐randomised controlled trials to allow for the clustered design. Data from studies with multiple treatment arms were incorporated according to the guidance included in Section 16.5.4 in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011).

Dealing with missing data

We followed the advice provided in Section 7.7.3 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We contacted study authors to obtain any relevant missing data or discuss data discrepancies. For trials for which we could not obtain missing data, we used the available data from the trial report. We planned to use the approaches described by Follmann 1992 to estimate the standard errors for those studies where the standard error was not explicitly reported, but it was not appropriate to attempt to derive or estimate the standard error.

Assessment of heterogeneity

Heterogeneity in the results of the trials was assessed by inspection of a graphical display of the results and by formal tests of heterogeneity. We planned to use a statistical test for heterogeneity (Chi ²) and the I² statistic to quantify inconsistency (which describes the percentage total variation across studies that is due to heterogeneity rather than chance, with I² greater than 50% considered to show substantial heterogeneity) for each meta‐analysis in addition to the pooled estimate and its associated 95% confidence interval. Such sources of heterogeneity might include, but were not limited to participant characteristics and nature of the interventions. Meta‐analysis was considered appropriate when studies were sufficiently similar in terms of clinical and metrological characteristics in conjunction with the Chi² test and I² statistic.

Assessment of reporting biases

We planned that this was assessed, where appropriate, by inspection of funnel plots of the results and formal tests where sufficient numbers of studies could be pooled for each comparison.

Data synthesis

We planned formal data synthesis in the form of meta‐analysis for trials with similar outcome measures, judged to have sufficiently similar experimental procedures and participants. We planned to combine risk ratios (for dichotomous data) and mean differences (for continuous data) using fixed‐effect models or using random‐effects models if more than three pooled trials.

Subgroup analysis and investigation of heterogeneity

We proposed the following subgroup analyses where data were available.

Age: subdivided into three groups: under 5, 6 to 11, 12 to 18 years old (as recommended by the British National Formulary when prescribing drugs to children).
Gender.
Site of LA.
Type of dental procedure.
Pharmacological techniques: subdivided into two groups: pharmacological techniques (as sedation) used on both control and study groups; pharmacological techniques not employed.

The proposed subgroups were suggested as they may influence primary or secondary outcomes. Age and cognitive development may influence co‐operation and type of intervention applied.

Although it is unclear whether gender will be determinant for acceptance of different types of interventions, it has been referred to in a number of studies as a possible influencing factor.

The type of dental procedure and site of injection may influence completion of treatment, as they may be considered more painful or anxiety inducing. Drilling and more invasive procedures have been considered the most anxiety‐inducing treatments (Majstorovic 2004).

As previously discussed, pharmacological behaviour management techniques were excluded as interventions. Sedation, however, was included as a distinct subgroup if the same technique/agent was equally used on the control and test groups.

Sensitivity analysis

Sensitivity analysis was planned if sufficient numbers of studies were to be included in any meta‐analyses to assess the robustness of the results based on the studies result for risk of bias.

Presentation of main results

We developed 'Summary of findings' tables using GRADEpro software (GRADEpro GDT 2015) for the main comparisons and the following outcomes of this review: acceptance of LA, completion of dental treatment, successful LA/painless treatment, self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA, patient satisfaction, and adverse events.

We assessed the certainty of the body of evidence with reference to the overall risk of bias of the included studies, the directness of the evidence, the inconsistency of the results, the precision of the estimates, and the risk of publication bias. We categorised the certainty of the body of evidence for each of the outcomes as high, moderate, low or very low (GRADE 2004).

Results

Description of studies

Results of the search

Database searching identified 2649 references, with an additional 21 records identified through other sources. Handsearches were continued up to May 2019 and repeated regularly, including email alerts, handsearching on relevant databases and handsearching of articles. After removing duplicates, the number of records was reduced to 1508. These records were screened independently and in duplicate and we discarded all but 83 studies for a full‐text assessment. From those records only 26 studies met the inclusion criteria of this review. One study is awaiting classification and seven are ongoing. We present this process as a flow chart in Figure 3.

Included studies

All 26 included studies were randomised controlled trials with parallel designs. There was substantial clinical heterogeneity across studies, in terms of the interventions used, timing, and nature of the outcomes measured.

Characteristics of the participants

We only included studies performed on participants under 18 years old or studies that provided separate data for children. The ages of the children in the included studies ranged from 2 to 16 years. One study did not report the age range of its sample, but reported on mean age in each group and only included children below the age of 15 years (Ujaoney 2013).

The number of children randomised ranged from 20 to 200, with a total number of 2435 children. All children recruited needed at least one appointment for treatment requiring local anaesthetic (LA).

Characteristics of the trial settings

Four studies were carried out in the UK (Al‐Namankany 2014; Allen 2002; Kandiah 2012; Tahmassebi 2009), three in the Netherlands (Nieuwenhuizen 2013; Versloot 2005; Versloot 2008), three in Iran (Aminabadi 2008; Aminabadi 2009b; Paryab 2014), three in the USA (Asarch 1999; Gibson 2000; Tung 2018), six in India (Kamath 2013; Mittal 2015; Nuvvula 2015; Oberoi 2016; Sridhar 2019; Ujaoney 2013), one in France (Huet 2011), two in Saudi Arabia (Al‐Khotani 2016; Baghlaf 2015), one in Egypt (Abdelmoniem 2016), one in Mexico (Carrasco 2017), one in Syria (Al‐Halabi 2018), and one was carried out in Korea (Lee 2013).

Characteristics of the interventions

All interventions of the included studies as previously discussed under Types of interventions can be found in Additional Table 5.

1. Interventions.

Factors for LA	Type of intervention	Characteristics of the intervention	Studies
Equipment factors
	Audiovisual technology
		Visual	We found no eligible studies
		Auditory	Nuvvula 2015
		Combined visual and auditory	Al‐Halabi 2018; Al‐Khotani 2016; Nuvvula 2015
	Topical anaesthetic
		Topical anaesthetic agents	We found no eligible studies
		Cooling of injection site	Aminabadi 2009b
	LA
		Gauge of needle	We found no eligible studies
		Temperature of cartridge	We found no eligible studies
	Electronic devices
		Infiltration devices	Allen 2002; Asarch 1999; Baghlaf 2015; Gibson 2000; Kandiah 2012; Mittal 2015; Nieuwenhuizen 2013; Tahmassebi 2009; Versloot 2005; Versloot 2008
		Intraosseous devices	We found no eligible studies
		Intraligamental devices	We found no eligible studies
	Others
		Needleless devices	We found no eligible studies
		Vibration device	Tung 2018
		Transcutaneous nerve stimulation	We found no eligible studies
		Camouflage syringe	Ujaoney 2013
Dentist factors (non‐pharmacological interventions)
	Imagery suggestion		We found no eligible studies
	Counter‐stimulation/distraction		Abdelmoniem 2016; Aminabadi 2008; Kamath 2013; Lee 2013; Paryab 2014; Tung 2018
	Systemic desensitisation		We found no eligible studies
	Hypnosis		Carrasco 2017; Huet 2011; Oberoi 2016
	Others
		Language ‐ non‐threatening words	We found no eligible studies
		Viewing/hiding needle	We found no eligible studies
		Time taken to deliver LA	We found no eligible studies
		Site of injection/order of treatment	We found no eligible studies
		Video modelling	Al‐Namankany 2014; Paryab 2014
		Breathing techniques	Sridhar 2019

Pain/anxiety scale or measurement	Description	Recorded by	Study
Abeer Children Dental Anxiety Scale (ACDAS)	19‐item, cognitive Likert scale	Self‐reported	Al‐Namankany 2014
Visual analogue scale (VAS) (including modified versions)	Self‐reporting of pain based on a line ranging from no pain to worst pain	Self‐reported; investigator; parents/guardians	Al‐Namankany 2014; Asarch 1999; Gibson 2000; Huet 2011; Kandiah 2012; Mittal 2015; Tahmassebi 2009; Versloot 2005; Versloot 2008
Parents' feedback questionnaires	Varied	Parents/guardians	Al‐Namankany 2014
4‐category scale of distress	4‐point scale measuring: body movement, crying, restraints, and stoppage of treatment	Investigator	Allen 2002
Sound, Eyes and Motor (SEM) scale	‐	Investigator	Abdelmoniem 2016; Aminabadi 2008; Aminabadi 2009b; Lee 2013; Mittal 2015
4‐category scale of distress	4‐point scale measuring: non‐interfering body movements, crying, movement disruptive to treatment, movement requiring restraint	Investigator	Asarch 1999
4‐category scale of distress	Body movement, crying, movements requiring restraint, movements requiring a temporary halt to treatment	Investigator	Baghlaf 2015; Gibson 2000
Modified Yale Preoperative Anxiety Scale (mYPAS)	22 items grouped into 5 categories ranging from 0 to 10	Investigator	Huet 2011
Modified Objective Pain Score (mOPS)	5 criteria ranging from 0 to 2, with an overall maximum score of 10	Investigator	Huet 2011
Modified Toddler‐Preschooler Postoperative Pain Scale (TPPPS)	5 parameters. Scores ranging from 0 to 10	Investigator	Kamath 2013
FACES Pain Scale Revised	6‐face scale ranging from 0 to 10	Self‐reported	Kamath 2013; Nieuwenhuizen 2013
Wong‐Baker Faces Scale	6‐face scale for pain behaviour raging from no hurt to hurts worst	Self‐reported	Abdelmoniem 2016; Baghlaf 2015; Nieuwenhuizen 2013
Modified Venham's scale	6‐point scale ranging from 0 (relaxed ) to 5 (out of contact or untreatable)	Investigator	Al‐Khotani 2016; Nieuwenhuizen 2013; Versloot 2005; Versloot 2008
Venham's scale	6‐point scale ranging from 0 (co‐operative) to 5 (unco‐operative)	Investigator	Paryab 2014; Tahmassebi 2009; Ujaoney 2013
Dental Subscale of the Children's Fear Survey Schedule (CFF‐DS)	15 items with a 5‐point scale per item. Ranging from 1 (not afraid at all) to 5 (very afraid)	Self‐reported	Nieuwenhuizen 2013; Versloot 2005; Versloot 2008
Modified Child Dental Anxiety Scale: faces: MCDAS(f)	6 questions scale, with the total score ranging from 5 (little or no anxiety) to 30 (extreme anxiety)	Self‐reported	Nuvvula 2015
Frankl scale	4‐point scale from definitely negative to definitely positive	Investigator	Paryab 2014
Scales for movement, crying, and overall behaviour	Movement (score range 1 to 4), crying (score range 1 to 4), and overall behaviour (score range 1 to 6)	Investigator	Ujaoney 2013
Venham's picture test (VPT) questionnaire	9‐point face scale ranging from 0 to 8	Investigator; self‐reported	Ujaoney 2013
Parental Emotional Stress Questionnaire (PESQ)	45‐point questionnaire with each statement ranging from 1 (strongly disagree) to 5 (strongly agree)	Parents/guardians	Ujaoney 2013
Recall questionnaires	‐	Parents/guardians	Ujaoney 2013
5‐category scale of distress	5‐point scale measuring body movement muscle tension, crying or screaming, verbal protest and bodily resistance	Investigator	Versloot 2005; Versloot 2008
Facial Image Scale (FIS)	5‐point scale with faces that best represent the child's emotional state	Self‐reported	Al‐Khotani 2016
Physical resistance to delivery of LA	High hand movements, leg movements, crying or verbal protests and/or orophysical resistance	Investigator	Oberoi 2016
Heart rate	Continuous values	Objective measurement	Al‐Khotani 2016; Mittal 2015; Oberoi 2016
Blood pressure	Continuous values	Objective measurement	Al‐Khotani 2016
Oxygenation	Continuous values	Objective measurement	Oberoi 2016

Audiovisual distraction compared to conventional treatment for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: audiovisual distraction  Comparison: conventional treatment
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional treatment	Risk with audiovisual distraction
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain‐related behaviour during LA (children who exhibited a negative versus positive behaviour; Frankl Behaviour Rating Scale (FBRS))	Study population		RR 0.13  (0.03 to 0.50)	60  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of audiovisual distraction on negative behaviour
	533 per 1000	69 per 1000  (16 to 267)
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio; VR: virtual reality
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

The wand compared to traditional LA for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: the wand  Comparison: traditional LA
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with traditional LA	Risk with the wand
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain‐related behaviour (any disruptive behaviour/sudden reaction/movement)	4 studies reported a benefit in using the wand while the remaining studies results suggested no difference between the 2 methods of delivering LA			704  (6 RCTs)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of the wand on negative behaviour  Pooling of studies was not appropriate due to heterogeneity in outcome scales, sites of injection, and time of outcome measures
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio; VAS: visual analogue scale
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

Counter‐stimulation or distraction compared to conventional treatment for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: counter‐stimulation or distraction  Comparison: conventional treatment
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional treatment	Risk with counter‐stimulation or distraction
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain (Sound, Eyes, and Motor (SEM) scale; dichotomous ‐ any pain versus no pain, higher score indicates high pain experience)	Study population		RR 0.12  (0.04 to 0.34)	134  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of counter‐stimulation on pain
	407 per 1000	49 per 1000  (16 to 139)
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; 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

Hypnosis compared to conventional treatment for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: hypnosis  Comparison: conventional treatment
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional treatment	Risk with hypnosis
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain (Modified Objective Pain Score (mOPS); VAS: 0 to 10, higher score indicates worse pain experience)	Conventional group mean was 2.86	MD 1.79 lower  (3.01 lower to 0.57 lower)	‐	29  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of hypnosis on pain
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio; VAS: visual analogue scale
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

Study	Outcome	Intervention (t2): audiovisual distraction	Control	Results
Nuvvula 2015	Anxiety: MCDAS(f)	Before LA: 22.20 (4.00 SD; 95% CI 20.70 to 23.70)	Before LA: 20.60 (2.40 SD; 95% CI 19.70 to 21.50)	t1 (before versus after LA): P = 0.001 t2 (before versus after LA): P = 0.001 Control (before versus after LA): P = 0.83 Intergroup comparison (P value): t1 versus control (before LA) = 0.70, (after LA) = 0.001; t2 versus control (before LA) = 0.14, (after LA) = 0.001; t1 versus t2 (before LA) = 1.00, (after LA) = 0.001
	Anxiety: MCDAS(f)	After LA: 8.30 (2.50 SD; 95% CI 7.30 to 9.20)	After LA: 20.90 (7.20 SD; 95% CI 18.20 to 23.50)
	Pulse rates	Before treatment: 104.60 (2.90 SD; 95% CI 103.50 to 105.60)	Before treatment: 95.40 (5.60 SD; 95% CI 93.30 to 97.50)	P value before treatment versus during LA: t1; t2 and control = 0.001 Intergroup comparison (P value): t1 versus control (before treatment) = 0.01, (during LA) = 0.001; t2 versus control (before treatment) = 0.01, (during LA) = 0.001; t1 versus t2 (before treatment and during LA) = 0.001
	Pulse rates	During LA: 109.40 (5.00 SD; 95% CI 107.50 to 111.20)	During LA: 119.00 (13.10 SD; 95% CI 114.10 to 123.90)
	Behaviour: Frankl scale	Before versus during LA (P value): t1 = 0.002; t2 = 0.001; control = 0.01 Intergroup comparison (P value): t1 versus control (before treatment) = 0.42, (after treatment) = 0.02; t2 versus control (before treatment) = 0.01, (after treatment) < 0.001; t1 versus t2 (before treatment) = 0.07, (after treatment) = 0.01
	Behaviour: Houpt scale	Intergroup comparison during LA (P value): t1 versus control = 0.31; t2 versus control = 0.003; t1 versus t2 = 0.009
Study	Outcome	Treatment with audiovisual distraction (group 1)	Control (group 2)	Results
Al‐Khotani 2016	Anxiety: FIS	Authors stated "there were no significant differences in mean (SD) FIS scores between the AV‐group; 1.93 (1.15) and CTR‐group (1.68 ± 0.86) (P = 0.570)." Mean values for the whole procedure given (including restorative treatment). However, no individual values for LA given other than a graph. For this reason it was not possible to include this outcome. Email sent to study author requesting separate values rather than whole treatment means
	Anxiety: modified Venham's clinical ratings of anxiety and co‐operative behaviour scale (MVARS)	The authors stated "When the co‐operative behaviour was analyzed (MVARS), there was a significant difference between groups with lower mean (SD) MVARS scores in the AV‐group (0.14 ± 0.36) compared to the CTR‐group (0.75 ± 0.52) (P = 0.03)." Mean values for the whole procedure given (including restorative treatment). However, no individual values for LA given other than a graph. For this reason it was not possible to include this outcome. Email sent to study author requesting separate values rather than whole treatment means
	Pulse rate	Before LA: mean: 95.90 (SD = 10.30) After LA: mean: 98.60 (SD = 12.20)	Before LA: mean: 94.30 (SD =14.40) After LA: mean: 99.40 (SD = 14.50)	Significant increase of pulse rate during LA in the control group (group 2) P = 0.04. Increase not significant in the study group (group 1) P = 0.27
	Blood pressure	Before LA: systolic blood pressure 111.70 (SD = 10.70) diastolic blood pressure 65.20 (SD = 7.50) After LA: systolic blood pressure 115 (SD = 6.30) diastolic blood pressure 66.80 (SD = 6.30)	Before LA: systolic blood pressure 112 (SD = 10) diastolic blood pressure 67.80 (SD = 9) After LA: systolic blood pressure 110.90 (SD = 9.60) diastolic blood pressure 64.50 (SD = 5.80)	There is actually a decrease in systolic blood pressure in the control group but the study authors say: "Although s‐BP seemed to be higher during injections with local anaesthesia in both groups" No comparative statistics for before and after LA only
Study	Outcome	Intervention: audiovisual distraction (tablet) (group 2)	Control (group 3)	Results
Al‐Halabi 2018	Behavioural assessment: the Face, Legs, Activity, Cry, Consolability (FLACC) scale	The authors provided data as comparison between groups with no individual data that could be used for any further analysis. The authors stated that no significant difference was noticed between 3 groups (P = 0.454). We have attempted to contact the main study author but no clarification was received
	Pain assessment: the Wong‐Baker Faces Pain Rating Scale	The authors stated that no significant difference was noticed between 3 groups in pain assessment (P = 0.536)
	Pulse rate: from when the patients seated to immediately after inferior alveolar nerve block	The authors stated that "Then one‐way Anova statistical test was done, significant difference was noticed between 3 groups in the heart pulse rate scale (P = 0.0430)." No other information was provided

Study	Outcome	Treatment	Control	Results
Aminabadi 2009a	Distress: SEM scale, 0 to 4 for each of 4 categories; intraoperatively, investigator	Sound: 1.15 Eyes: 1.50 Movement: 1.76 Sum: 4.41 (n = 80)	Sound: 2.54 Eyes: 3.25 Movement: 2.78 Sum: 8.57 (n = 80)	Within groups: P > 0.05 Between groups: P < 0.05 (Anova)

Pre‐cooling of the injection site compared to conventional treatment for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: pre‐cooling of the injection site  Comparison: conventional treatment
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional treatment	Risk with pre‐cooling of the injection site
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain (SEM scale (Sound, Eyes, and Motor scale))	‐		‐	160 (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of pre‐cooling of the injection site on pain
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; RCT: randomised controlled trial
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

Study	Outcome	Intervention		Control		Results
Allen 2002	Pain behaviour (4‐category scale of distress), 15 intervals, from the moment the dentist started looking and touching the child, until he stopped (overall pain behaviour)	Disruptive behaviour: 50%		Disruptive behaviour: 71%		t = 2.10 P < 0.50 Fisher's exact test
		Crying: 30%		Crying: 57%		t = 2.40 P < 0.50 Fisher's exact test
		Body movement: 28%		Body movement: 49%		t = 2.43 P < 0.50 Fisher's exact test
		Restraint: 3%		Restraint: 34%		t = 3.44 P < 0.10 Fisher's exact test
	Pain behaviour (4‐category scale of distress), 15 intervals, from the moment the dentist started looking and touching the child, until he stopped (initial 15 seconds)	Disruptive behaviour: 25%		Disruptive behaviour: palatal: 80% buccal: 75%		"... the mean number of 15‐second intervals with restraints was significantly fewer during the entire Wand injection (mean = 0.30 +/‐ 0.73) than during the 2 traditional injections (1.15 +/‐ 1.69), t (25.9) = 2.06, P < 0.5" Fisher's exact test
		Crying: 15%		Crying: palatal: 70% buccal: 55%
		Body movement: 15%		Body movement: palatal: 60% buccal: 40%
		Restraint: 0%		Restraint: palatal: 45% buccal: 20%
Study	Outcome	Intervention		Control		Results
Asarch 1999	Pain perception: VAS, 10‐point scale; immediately after LA, participant rating	Block: 5.00 Buccal: 4.38 Palatal: 3.80		Block: 4.062 Buccal: 3.35 Palatal: 3.93		No further information
Study	Outcome	Group 1: traditional LA inferior alveolar nerve block	Group 2: CCLAD inferior alveolar nerve block		Group 3: CCLAD intraligamental	Results
Baghlaf 2015	Pain behaviour: 4‐point scale, 15‐second intervals	Mean: 0.8165 (SD = 0.766, n = 31)	Mean: 0.4513 (SD = 0.60, n = 30)		Mean: 0.0890 (SD = 0.105, n = 30)	ANOVA P < 0.50 Group 3 statistically significantly lower (P < 0.01)
	Pain perception: Wong‐Baker Faces Pain Rating Scale following LA	Mean: 1.39 (SD = 0.20, n = 31)	Mean: 0.87 (SD = 0.133, n = 30)		Mean: 0.13 (SD = 0.063, n = 30)	Post‐hoc test, P < 0.50 Between groups 1 and 2: P = 0.044 Between groups 2 and 3: P = 0.003 Between groups 1 and 3: P < 0.001
Study	Outcome	Intervention		Control		Results
Gibson 2000	Pain behaviour: 4‐category scale of distress, 15 intervals, from puncture. Unclear when it stopped but discussed it was "coding if injection procedure"	Disruptive behaviour (%): palatal: 77% buccal: 45%		Disruptive behaviour (%): 42%		".... significantly fewer patients cried or exhibited body movements during the first interval of the wand injection than patients given the traditional palatal injection (Chi² +6.62, 11.78, respectively P < 0.5)"
		Crying (%): palatal: 74% buccal: 32%		Crying (%): 42%
		Body movement (%): palatal: 39% buccal: 19%		Body movement (%): 3%
		Restraint (n): palatal: 5 buccal: 1%		Restraint (n): 1 1%
	Pain perception: VAS, 10‐point‐scale; immediately after LA, participant rating	Palatal: 4.90 Buccal: 2.70		3.40		Less patients scored high pain ratings in the wand compared to palatal injection (Chi² = 3.32, P < 0.10)
Study	Outcome	Intervention		Control		Results
Kandiah 2012	Pain: modified VAS 0 to 100%; after LA. Percentages were divided into 3 categories: no pain (< 20%), mild (20% to 40%), moderate (40% to 60%), severe (60% to 80%), intolerable pain (> 80%)	No pain: 14/13 Mild: 0/15 Moderate: 1/15		No pain: 12/13 Mild: 1/15 Moderate: 2/15		"The treatment group had marginally more patients (14/15) expressing that no pain at all was experienced as opposed to the control group (12/14)"
	Time taken to deliver LA (minutes)	Median: 2.200 (1.53 to 4.21 IQR) n = 15		Median: 2.120 (1.39 to 3.40 IQR) n = 15		"The findings from this study suggest that the median for both groups was approximately the same"
Study	Outcome	Intervention		Control		Results
Mittal 2015	Self‐reported anxiety: VAS immediately after LA	Buccal infiltration: mean VAS: 1.24 (SD = 0.74) Palatal infiltration: mean VAS: 2.94 (SD = 1.35)		Buccal infiltration: mean VAS: 1.16 (SD = 0.96) Palatal infiltration: mean VAS: 2.38 (SD = 1.23)		Buccal infiltration treatment versus control P = 0.64 Palatal injection treatment versus control P = 0.03 (t test)
	Observed anxiety: using the SEM scale, ranging from 1 to 4. Measured by operator and an independent investigator who was present in the surgery	Buccal infiltration: mean SEM: 1.64 (SD = 1.14) Palatal infiltration: mean SEM: 3.16 (SD = 1.28)		Buccal infiltration: mean SEM: 1.08 (SD = 0.94) Palatal infiltration: mean SEM: 2.44 (SD = 1.31)		Buccal infiltration treatment versus control P = 0.01 Palatal injection treatment versus control P = 0.01 (t test)
	Physiological assessment: heart rate measured with a pulse oximeter. Readings were average of readings taken on 3 occasions: 8 minutes prior to LA: readings every 2 minutes; during buccal infiltration: readings every 15 seconds; and during palatal infiltration: readings every 15 seconds	Before injection: mean HR: 83.52 (SD = 5.10) During buccal infiltration: mean HR: 99.30 (SD = 7.90) During palatal injection: mean HR: 102.26 (SD = 7.61)		Before injection: mean HR: 83.64 (SD = 4.54) During injection: mean HR: 102.46 (SD = 9.38)		Buccal infiltration treatment versus control P = 0.36 Palatal injection treatment versus control P = 0.91 (t test)
Study	Outcome	Intervention		Control		Results
Tahmassebi 2009	Participant‐reported anxiety: modified Venham's scale, 1 to 8; prior to and after LA	No separate descriptives for conventional LA/the wand. Difference of anxiety between the 2 groups given on a graph				Mean (anxiety difference): ‐2 (1.96 SD), n = 18, P = 0.976 (95% CI); 2‐sample t‐test "There was no significant difference in anxiety change between the 2 groups at 5% level with P value of 0.976"
	Participant‐reported pain: modified VAS, 0 to 100%, after LA. Percentages were divided into following categories: no pain (< 20%), mild (20% to 40%), moderate (40% to 60%), severe (60% to 80%), intolerable pain (> 80%)	No pain: 50%		No pain: 45%		"... no significant difference in pain sensation between the 2 groups at 5% level (P = 0.710)" 2‐sample t‐test
		Mild: 15%		Mild: 10%
		Moderate: 5%		Moderate: 35%
		Severe/intolerable: 15%		Severe/intolerable: 5%
	Operator‐reported pain: VAS, 0 to 100%, after LA. Percentages were divided into following categories: no pain (< 20%), mild (20% to 40%), moderate (40% to 60%), severe (60% to 80%), intolerable pain (> 80%)	Mild pain: 20%		Mild pain: 40%		"There was also no difference in the investigator's pain estimation between the 2 groups at a 5% level (P = 0.693)" 2‐sample t‐test
		Intolerable pain: 5%		Intolerable pain: 0%
	Parent‐reported pain: VAS, 0 to 100%, after LA. Percentages were divided into following categories: no pain (< 20%), mild (20% to 40%), moderate (40% to 60%), severe (60% to 80%), intolerable pain (> 80%)	Not reported		Not reported		"There was no significant difference in parent pain estimation between the 2 groups (P = 0.640)" 2‐sample t‐test
Study	Outcome	Intervention		Control		Results
Versloot 2005	Pain‐related behaviour: 5‐category scale of distress, 15‐second intervals, prior to and during delivery of LA, investigator. The occurrence of behaviours was summed and divided over the number of intervals to calculate the mean score of the pain‐related behaviours	Muscle tension				Anticipation phase: "no significant differences were found" First 15‐second interval: "children in the wand group showed less body movement, muscle tension, and verbal protest" Second 15‐second interval: "children injected using the wand still showed less muscle tension and less verbal protest"
		Anticipation: 48 (n = 67) First interval: 72 (n = 67) Second interval: 73 (n = 67)		Anticipation: 62 (n = 58) First interval: 91 (n = 58) Second interval: 93 (n = 42)
		Cry/scream
		Anticipation: 13 (n = 67) First interval: 33 (n = 67) Second interval: 37 (n = 67)		Anticipation: 19 (n = 58) First interval: 50 (n = 58) Second interval: 45 (n = 42)
		Verbal protest
		Anticipation: 8 (n = 67) First interval: 12 (n = 67) Second interval: 2 (n = 67)		Anticipation: 10 (n = 58) First interval: 26 (n = 58) Second interval: 12 (n = 42)
		Body movement
		Anticipation: 12 (n = 67) First interval: 13 (n = 67) Second interval: 18 (n = 67)		Anticipation: 24 (n = 58) First interval: 35 (n = 58) Second interval: 17 (n = 42)
		Resistance
		Anticipation: 5 (n = 67) First interval: 8 (n = 67) Second interval: 8 (n = 67)		Anticipation: 9 (n = 58) First interval: 14 (n = 58) Second interval: 14 (n = 42)
	Distress: modified Venham's clinical rating of anxiety and co‐operative behaviour, 6 points, 1 to 6; prior to and during delivery of LA, investigator	Anticipation (prior to LA)				"Less distress was displayed during the first 2 intervals of the injection phase when injected using the wand than when injected in the traditional way although this difference did not reach significance" Multivariate GLM, F‐test (3105) = 1.29, P = 0.283
		Mean: 0.81 (95% CI 0.54 to 1.08) n = 67		Mean: 1.12 (95% CI 0.78 to 1.46) n = 42
		First 15‐second interval
		Mean: 1.09 (95% CI 0.81 to 1.37) n = 67		Mean: 1.48 (95% CI 1.13 to 1.83) n = 42
		Second 15‐second interval
		Mean: 1.09 (95% CI 0.82 to 1.37) n = 67		Mean: 1.52 (95% CI 1.18 to 1.87) n = 42
	Self‐reported pain: modified VAS, 11 points (0 to 10); after LA, participants	Mean: 4.40 (3.22 SD)		Mean: 3.76 (3.57 SD)		No difference
Study	Outcomes	Intervention		Control		Results
Versloot 2008	Pain‐related behaviour: 5‐category scale of distress, 15‐second intervals; prior to and during delivery of LA, investigator. The occurrence of behaviours was summed and divided over the number of intervals to calculate the mean score of the pain‐related behaviours	First appointment
		Mean: 1.03 (0.83 SD) n = 66		Mean: 1.14 (1.27 SD) n = 74		"There was no difference for (…) the mean number of pain‐related behaviours (…) between children injected with the wand or the traditional injection" Mancova used
		Second appointment
		Mean: 0.89 (1.21 SD) n = 55		Mean: 1.19 (1.20 SD) n = 64		"... there was no difference for (…) the mean number of pain‐related behaviours (…) for children injected with the wand or the traditional injection" Mancova used
	Distress: modified Venham's clinical rating of anxiety and co‐operative behaviour, 6 points, 1 to 6; prior to and during delivery of LA, investigator	First appointment
		Mean: 1.38 (0.94 SD) n = 66		Mean: 1.48 (1.24 SD) n = 74		"There was no difference for the mean Venham score, (…) between children injected with the wand or the traditional injection" Mancova used
		Second appointment
		Mean: 1.31 (1.21 SD) n = 55		Mean: 1.50 (1.17 SD) n = 64		"Thus there was no difference for the mean Venham score, (…) for children injected with the wand or the traditional injection" Mancova used
	Self‐reported pain: modified VAS, 11 points (0 to 10); after LA, participants	First appointment
		Mean: 3.26 (3.27 SD) n = 66		Mean: 2.77 (3.00 SD) n = 74		"There was no difference for the (…) self‐reported pain score between children injected with the wand or the traditional injection" Mancova used
		Second appointment
		Mean: 3.49 (3.40 SD) n = 55		Mean: 3.77 (3.30 SD) n = 64		"There was no difference for the mean (…) the self‐reported pain score for children injected with the wand or the traditional injection" Mancova used

Study	Outcome	Intervention 1: Sleeper One		Intervention 2: the wand		Results
Nieuwenhuizen 2013	Pain‐related behaviour: modified Wong‐Baker Faces Scale, 15 seconds. Reported separately for each category: body movement, muscle tension, crying and screaming, verbal protest, and bodily resistance. The frequency of the behaviour was divided by the total number of intervals scored	Muscle tension	Mean: 0.41 (0.39 SD), n = 52	Muscle tension	Mean: 0.42 (0.38 SD), n = 60	P = 0.765 (Mann–Whitney U test, P < 0.01)
		Crying	Mean: 0.17 (0.31 SD), n = 52	Crying	Mean: 0.25 (0.34 SD), n = 60	P = 0.220 (Mann–Whitney U test, P < 0.01)
		Verbal protest	Mean: 0.07 (0.17 SD), n = 52	Verbal protest	Mean: 0.07 (0.15 SD), n = 60	P = 0.507 (Mann–Whitney U test, P < 0.01)
		Body movement	Mean: 0.03 (0.06 SD), n = 52	Body movement	Mean: 0.09 (0.18 SD), n = 60	P = 0.165 (Mann–Whitney U test, P < 0.01)
		Resistance	Mean: 0.01 (0.05 SD), n = 52	Resistance	Mean: 0.07 (0.22 SD), n = 60	P = 0.070 (Mann–Whitney U test, P < 0.01)
	Distress: modified Venham's scale, 0 to 5, highest score of appointment	Mean 0.96 (0.86 SD), n = 52		Mean 1.42 (1.15 SD), n = 60		P = 0.842 (Mann–Whitney U test, P < 0.01)
	Self‐reported pain: FACES Pain Scale Revised (FPS‐R), 0 to 10	Mean 3.42 (4.16 SD), n = 52		Mean 4.10 (3.97 SD), n = 60		P = 0.265 (Mann–Whitney U test P < 0.01)

Study ID
First author
Reviewer ID
Year of publication
Title (First 5 words)
Country of study

	Yes	No	Unclear
Was a sample size calculation reported?
Was method of generation of randomised sequence adequate? (Yes = generated by random number table, tossed coin, and shuffled cards) (No = alternate assignment, hospital number and odd/even DOB) (Unclear = reference to randomisation but method not reported or inadequately explained)
Was allocation concealment adequate? (Yes = central registrar, sequentially coded containers, sequentially coded opaque envelopes) (No = randomisation not concealed (e.g. alternate assignment, hospital number, odd/even DOB) or not reported) (Unclear = reference to allocation concealment but method not reported or inadequately explained)
Was the patient blinded to the therapy?
Was the operator blinded to the therapy?
Was the assessor blinded to the therapy?
Were inclusion and exclusion criteria clearly defined in the text?
Did the text state there were no withdrawals?
Were outcomes of patients who withdrew or were excluded after allocation detailed separately?
Were outcomes of patients who withdrew or were excluded after allocation included in an intention‐to‐treat analysis?
Were treatment and control groups described at entry?
Was the use of an intention‐to‐treat analysis stated?

	Intervention	Number recruited at baseline	Number at the end	Reason for dropouts given
Control group
Test 1
Test 2
Test 3

Intervention	Index used	Outcome (describe nature of results)
Control
Test 1
Test 2
Test 3

The wand compared to Sleeper One for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: the wand  Comparison: Sleeper One
Outcomes	*Anticipated absolute effects^ (99% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with Sleeper One	Risk with the wand
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain‐related behaviour (any disruptive behaviour (modified Wong‐Baker Faces Scale)	Sleeper One group mean was 0.03	MD 0.06 higher  (0.01 higher to 0.11 higher)	‐	112  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of the wand on pain‐related behaviour (muscle tension, crying, verbal protest, resistance, and body movement) when compared to Sleeper One
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 99% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 99% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial
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

Camouflage syringe compared to conventional syringe for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: camouflage syringe  Comparison: conventional syringe
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional syringe	Risk with camouflage syringe
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain‐related behaviour	Study population		RR 0.02  (0.00 to 0.37)	100  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of using a camouflage syringe on pain‐related behaviour (crying (disruptive behaviour))
	420 per 1000	8 per 1000  (0 to 155)
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; 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

Electrical counter‐stimulation device (DentalVibe) compared to no stimulation for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: electrical counter‐stimulation device (DentalVibe)  Comparison: no stimulation
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with no stimulation	Risk with electrical counter‐stimulation device (DentalVibe)
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain (Wong‐Baker Faces Pain Scale; 0 to 10 where 10 is worst pain)	Control group mean was 3.56	MD 1.34 lower  (2.35 lower to 0.33 lower)	‐	100  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of the DentalVibe on pain
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial
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

Study	Outcome	Intervention 1: counter‐stimulation (groups C+SA)	Intervention 2: distraction and counter‐stimulation (group CD+SA)	Control: conventional LA (group SA)	Results
Aminabadi 2008	Distress: Sound, Eyes, and Motor (SEM) scale; 0 to 4 for each of 4 categories, intraoperatively, investigator	Sound: 1.67 Eyes: 1.67 Movement: 1.73 Sum: 5.07 (n = 26)	Sound: 1.26 Eyes: 1.03 Movement: 1.12 Sum: 3.41 (n = 26)	Sound: 2.75 Eyes: 2.67 Movement: 2.83 Sum: 8.25 (n = 26)	"... difference between group SA and group C+SA was statistically significant (P < 0.05); group CD+SA surpassed group SA (P < 0.05)... Pain reaction on C+SA significantly more than group CD+SA (P < 0.05)"

Counter‐stimulation and distraction, versus conventional treatment for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: counter‐stimulation and distraction  Comparison: conventional treatment
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with conventional treatment	Risk with counter‐stimulation and distraction
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA	No numeric data reported. Study authors reported lower distress values for all categories in the combined counter‐stimulation and distraction group. This difference was significant when compared to the conventional treatment group and the counter‐stimulation only group		‐	78 (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of counter‐stimulation and distraction on distress/pain
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; RCT: randomised controlled trial
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

Video modelling acclimatisation for LA compared to oral hygiene video for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: video modelling acclimatisation for LA  Comparison: oral hygiene video
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with oral hygiene video	Risk with video modelling acclimatisation for LA
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: anxiety/pain experience (VAS, higher scores indicate worsened anxiety)	Oral hygiene video group mean was 63.50	MD 37.16 lower  (50.94 lower to 23.38 lower)	‐	66  (1 RCT)	⊕⊕⊝⊝  LOW^a	Video modelling may reduce anxiety/pain experience during delivery of LA when compared to oral hygiene video
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial; VAS: visual analogue scale
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

Video modelling acclimatisation compared to acclimatisation in clinic for increasing acceptance of LA in children and adolescents having dental treatment
Patient or population: children and adolescents having dental treatment  Setting: dental clinic  Intervention: video modelling acclimatisation  Comparison: acclimatisation in clinic
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	Number of participants  (studies)	Certainty of the evidence  (GRADE)	What this means
	Risk with acclimatisation in clinic	Risk with video modelling acclimatisation
Acceptance of LA	Included studies did not report on this outcome
Completion of dental treatment	Included studies did not report on this outcome
Successful LA/painless treatment	Included studies did not report on this outcome
Self‐ or observational assessment of intraoperative distress/pain/acceptance of treatment during provision of LA: pain‐related behaviour (Frankl scale)	Acclimatisation in clinic group mean was 3.02	MD 0.01 higher  (0.33 lower to 0.35 higher)	‐	46  (1 RCT)	⊕⊝⊝⊝  VERY LOW^a	Evidence is uncertain regarding the effect of video modelling acclimatisation on co‐operation behaviour levels when compared to acclimatisation in clinic
Patient satisfaction: measured by questionnaires	Included studies did not report on this outcome
Adverse effects	Included studies did not report on this outcome
^*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)    CI: confidence interval; LA: local anaesthetic; MD: mean difference; RCT: randomised controlled trial
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

	Yes	No
Children and adolescents up to 18 years old having dental treatment under local anaesthetic
Primary outcome of review reported ‐ acceptance of local anaesthetic
Secondary outcome of review reported ‐ completion of treatment
Secondary outcome of review reported ‐ assessment of intraoperative distress during provision of local anaesthetic
Study designed as RCT

Number of eligible participants		Number enrolled in study
Number of males		Number of females
Mean age (SD)		Age range

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain‐related behaviour ‐ dichotomous (participant with negative behaviour versus participant with positive behaviour)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 Audiovisual distraction with 3D video glasses versus control group during LA	1	60	Risk Ratio (M‐H, Fixed, 95% CI)	0.13 [0.03, 0.50]
1.2 Music distraction group versus control during LA	1	60	Risk Ratio (M‐H, Fixed, 95% CI)	0.31 [0.13, 0.74]
1.3 Audiovisual distraction with 3D video glasses versus music group during LA	1	60	Risk Ratio (M‐H, Fixed, 95% CI)	0.4 [0.08, 1.90]
2 Pain‐related behaviour (FLACC scale 0–10, higher score indicates worst behaviour)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.1 VR box versus control LA	1	67	Mean Difference (IV, Fixed, 95% CI)	‐0.03 [‐1.03, 0.96]
2.2 Tablet versus control LA	1	68	Mean Difference (IV, Fixed, 95% CI)	0.67 [‐0.41, 1.76]
2.3 VR box versus tablet	1	67	Mean Difference (IV, Fixed, 95% CI)	‐0.71 [‐1.84, 0.43]
3 Pain experience (Wong‐Baker Faces score 0‐5, higher score indicates worst pain)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
3.1 VR box versus control LA	1	67	Mean Difference (IV, Fixed, 95% CI)	0.04 [‐0.41, 0.48]
3.2 Tablet versus control LA	1	68	Mean Difference (IV, Fixed, 95% CI)	0.22 [‐0.28, 0.73]
3.3 VR box versus tablet	1	67	Mean Difference (IV, Fixed, 95% CI)	‐0.19 [‐0.73, 0.35]
4 Anxiety after LA (any distraction vs control) (Modified Child Dental Anxiety Scale score form 5‐30, higher scores indicate higher anxiety)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
4.1 Audiovisual distraction with 3D video glasses versus control group after LA	1	60	Mean Difference (IV, Fixed, 95% CI)	‐12.60 [‐15.33, ‐9.87]
4.2 Music distraction group versus control after LA	1	60	Mean Difference (IV, Fixed, 95% CI)	‐6.80 [‐9.82, ‐3.78]
5 Anxiety between distraction techniques after LA (Modified Child Dental Anxiety Scale score form 5‐30, higher scores indicate higher anxiety)	1	60	Mean Difference (IV, Fixed, 95% CI)	‐5.80 [‐7.61, ‐3.99]
6 Pulse rate during LA (any distractions versus control)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
6.1 Music distraction group versus control during LA	1	60	Mean Difference (IV, Fixed, 95% CI)	‐14.40 [‐19.20, ‐9.60]
6.2 Audiovisual distraction versus control group during LA	1	60	Mean Difference (IV, Fixed, 95% CI)	‐9.60 [‐14.62, ‐4.58]
6.3 Pulse rate difference between 2 distraction techniques during LA	1	60	Mean Difference (IV, Fixed, 95% CI)	‐4.80 [‐6.87, ‐2.73]
7 Pulse rate before and after LA	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
7.1 VR box versus control LA	1	67	Mean Difference (IV, Fixed, 95% CI)	2.88 [‐1.78, 7.53]
7.2 Tablet versus control LA	1	68	Mean Difference (IV, Fixed, 95% CI)	6.26 [2.04, 10.47]
7.3 VR box versus tablet	1	67	Mean Difference (IV, Fixed, 95% CI)	‐3.38 [‐8.42, 1.66]

PERMALINK

Interventions for increasing acceptance of local anaesthetic in children and adolescents having dental treatment

Joana Monteiro

Ajit Tanday

Paul F Ashley

Susan Parekh

Hamdan Alamri

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Summary of findings

Background

Description of the condition

Description of the intervention

Patient factors

Equipment factors

Dentist factors

Non‐pharmacological interventions

Pharmacological interventions

How the intervention might work

Why it is important to do this review

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Types of interventions

Types of outcome measures

Primary outcomes

Secondary outcomes

Search methods for identification of studies

Electronic searches

Searching other resources

Data collection and analysis

Selection of studies

Data extraction and management

Assessment of risk of bias in included studies

1.

2.

Measures of treatment effect

Unit of analysis issues

Dealing with missing data

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

Presentation of main results

Results

Description of studies

Results of the search

3.

Included studies

Characteristics of the participants

Characteristics of the trial settings

Characteristics of the interventions

1. Interventions.

Characteristics of the outcomes

2. Outcome measures of included studies.

Excluded studies

Risk of bias in included studies

Allocation

Sequence generation

Concealment of allocation

Blinding

Blinding of participants and personnel (performance bias)

Blinding of outcome assessment (detection bias)

Incomplete outcome data

Selective reporting

Other potential sources of bias

Overall risk of bias

Effects of interventions

Summary of findings for the main comparison. Audiovisual distraction compared to conventional treatment for increasing acceptance of local anaesthetic in children and adolescents having dental treatment.

Summary of findings 2. The wand compared to traditional local anaesthetic for increasing acceptance of local anaesthetic in children and adolescents having dental treatment.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Any disruptive behaviour (body movements, crying, restraint and stoppage of treatment) by the child during LA	3		Mean Difference (IV, Random, 95% CI)	Totals not selected
2 Pain perception/pain experience during the intervention	4		Mean Difference (IV, Random, 95% CI)	Totals not selected
2.1 Any site of injection	4		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]
2.2 Palatal site injection	1		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]
3 Pain perception during the intervention (dichotomous)	2		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 No pain versus any pain	2	68	Risk Ratio (M‐H, Fixed, 95% CI)	1.15 [0.83, 1.59]
3.2 No pain and mild pain versus any pain	2	68	Risk Ratio (M‐H, Fixed, 95% CI)	1.12 [0.85, 1.47]
4 Anxiety changes during the intervention	4		Mean Difference (IV, Random, 95% CI)	Totals not selected
4.1 Any site of injections	4		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]
4.2 Palatal injection	1		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Any disruptive behaviour (body movements either present or absent during each 15‐second interval of the injection phase)	1	112	Mean Difference (IV, Fixed, 99% CI)	0.06 [0.01, 0.11]
2 Pain experience (Faces Pain Scale‐Revised (FPS‐R) 0–10 with higher score indicates worst pain)	1	112	Mean Difference (IV, Fixed, 99% CI)	0.68 [‐1.31, 2.67]
3 Anxiety changes (modified Venham's, 0‐6 scale, higher score indicates higher anxiety)	1	112	Mean Difference (IV, Fixed, 99% CI)	0.46 [‐0.03, 0.95]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain‐related behaviour	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 Children who cried	1	100	Risk Ratio (M‐H, Fixed, 95% CI)	0.02 [0.00, 0.37]
1.2 Children who did not smile	1	100	Risk Ratio (M‐H, Fixed, 95% CI)	0.12 [0.06, 0.26]
2 Overall anxiety and behavioural changes (Venham's clinical rating scale, from 0 to 5 with 5 being the worst)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

Outcome or subgroup title	No. of studies	Statistical method	Effect size
1 Pain experience (dichotomous)	2	Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
1.1 Any pain versus no pain (comfort versus discomfort)	2	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 Pain perception	3	Mean Difference (IV, Fixed, 95% CI)	Totals not selected
2.1 Children aged 6‐14 years	3	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.2 Children younger than 5 years old	1	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Anxiety changes (pulse rates)	2	Mean Difference (IV, Fixed, 95% CI)	Totals not selected
3.1 Changes from baseline to during injection LA	1	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.2 Pulse rate during LA	1	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain experience (self‐reported pain)	1	100	Mean Difference (IV, Fixed, 95% CI)	‐1.34 [‐2.35, ‐0.33]
2 Anxiety changes (pulse rates changes from baseline to during injection recorded pulse rates)	1	100	Mean Difference (IV, Fixed, 95% CI)	0.60 [‐3.06, 4.26]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain perception	2		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2 Pain experience (dichotomous ‐ VAS, 0‐10, higher score indicates worst pain)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 Pain reporting (VAS >3)	1	29	Risk Ratio (M‐H, Fixed, 95% CI)	0.24 [0.06, 0.92]
3 Anxiety (number of participants that exhibit physical or verbal resistance to LA ‐ dichotomous)	1	200	Risk Ratio (M‐H, Fixed, 95% CI)	0.47 [0.34, 0.65]
4 Physiological assessment ‐ pulse rates	2		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
4.1 Pulse rate before LA	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.2 Pulse rate during LA	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.3 Pulse rate after LA	1		Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Co‐operative behaviour level using Frankl 4‐point index	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
2 Anxiety changes (6‐point index, higher score indicates worst anxiety)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

Methods	Study design: randomised trial, parallel Location: Egypt Number of centres: 1 Setting: hospital/university Recruitment period: not reported
Participants	Inclusion criteria: positive or definitely positive Frankl scale Exclusion criteria: not reported Number of participants randomised: 90 Number of participants evaluated: 90 Number of males/ females: not reported Age: Group 1: 7.18 ± 1.94 years; Group 2: 7.02 ± 2.2 years; Group 3: 7.65 ± 1.8 years
Interventions	Group 1: passive distraction (listening to the same song on headphones); during LA delivery Group 2: active distraction (moving legs up and down alternatively as a game); during LA delivery
Outcomes	Pain perception during administration of local anaesthesia: assessed by the Sound, Eyes, and Motor (SEM) scale and Wong‐Baker Faces Pain Rating Scale Observed pain: assessed by Sound, Eyes, and Motor (SEM) scale. It is divided into 2 categories of comfort and discomfort
Notes	Declarations of interest: not reported Sample size calculation performed and discussed No reliability calculations
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not enough information on the randomisation procedure Quote: "The study sample was randomly divided into three equal groups 30 children each"
Allocation concealment (selection bias)	Unclear risk	Not reported or discussed
Blinding of participants and personnel (performance bias)   All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias)   All outcomes	High risk	Not reported, although authors discuss one clinician performed the treatment and another one evaluated the child
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No excluded patients
Selective reporting (reporting bias)	Low risk	All recorded outcomes were reported on within the results section
Other bias	Low risk	No further bias

Methods	Study design: prospective randomised controlled trial, parallel Location: Saudi Arabia Number of centres: 1 Setting: university hospital Recruitment period: September 2007 to May 2008 Funding source: not discussed
Participants	Inclusion criteria: general good health, no previous dental experience involving LA administration for the last 2 years and restorative treatment required under LA Exclusion criteria: previous unpleasant experience in medical setting or known dental phobia as reported in the medical records, need for pharmacological management to co‐operate or medical disability such as the history of seizures or convulsion disorders, nystagmus, vertigo or equilibrium disorders, eye problems and autism Number of participants randomised: 56 Number of participants evaluated: 56 Number of males/females: 22 males, 34 females Mean age (years): Group 1: 8.3 (range 7 to 9.6), Group 2: 8.1 (range 7 to 9.8) Age range: 7 to 9 years old (mean: 8.2 +/‐ SD 0.8)
Interventions	Group 1: audiovisual distraction during treatment including delivery of LA Group 2 (control): conventional treatment, including delivery of LA
Outcomes	Anxiety: measured preoperatively and postoperatively using the Facial Image Scale (FIS). Self‐reported, 5 faces that best represent patient's emotional state, ranging from 1 to 5 Anxiety and co‐operation measured by Modified Venham's clinical ratings of anxiety and co‐operative behaviour scale (MVARS). This scale has 6 categories ranging from 0 to 5 Anxiety measuring blood pressure (systolic and diastolic) and pulse rate. Measurements made at: intraoral examination, injection with LA, application of rubber dam, cavity preparation, and tooth restoration
Notes	CONSORT flow chart not presented Declarations of interest: the authors declare no conflicts of interest Sample size calculation made and discussed however, no reference to previous papers or pilot studies for information Consent form and ethical approval obtained Study performed by the same paediatric dentist Pilot study performed with 6 patients that were not included in the study Trained, independent assessors. Interexaminers reliability obtained (Cohen's kappa: 0.85)
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "The randomization was performed by a dental assistant not participating in the study by assigning the first patient to either group by the toss of a coin, after that the next patient went to the other group" Comment: method described implies that the first patient was assigned randomly, but that every patient after that was assigned via alternation
Allocation concealment (selection bias)	Unclear risk	No discussion regarding allocation concealment is presented
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Children not blinded. No discussion regarding blinding of personnel Quote: "... in the AV‐group, before the start of the restorative procedure, the child was introduced to the AV‐system (i‐theatreTM) and allowed to choose his/her favourite cartoon…"
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No discussion on how blinding of observers was carried out. No discussion whether children in the control group were wearing AV glasses or similar in order to blind raters Quote: "The two observers were blinded, and the tapes were coded during the main study"
Incomplete outcome data (attrition bias)   All outcomes	High risk	Numbers of patients not presented on tables or discussed in text. No CONSORT flow chart therefore no information on number of dropouts and reasons for them
Selective reporting (reporting bias)	Unclear risk	Descriptive statistics on number of patients not presented
Other bias	Low risk	No further bias identified

Methods	Study design: randomised controlled trial, parallel design Location: United Kingdom Number of centres: 1 Setting: hospital Recruitment period: October 2010 to March 2011 Funding source: not reported
Participants	Inclusion criteria: the availability of DVD facilities at home; children aged 6 to 12 years of age; healthy children with American Society of Anaesthesiologists ASA scale, class I and II; and children who were assessed to be dentally anxious based on the score of ≥ 26 on ACDAS Exclusion criteria: children who did not meet the inclusion criteria; children with a learning disability; children who needed emergency dental treatment Number of participants randomised: 68 Number of participants evaluated: 56 Number of males/females: 22 males (Group 1: 11; Group 2: 11); 34 females (Group 1: 16; Group 2: 18) Group 1 mean age (years) = 9.15, median = 9, SD = 2.75 years, 95% CI of the mean: 8.06 to 10.24 years Group 2 mean age (years) = 9.07, median = 9, SD = 2.47 years, 95% CI of the mean: 8.13 to 10.01 years Age range: 6 to 12 years
Interventions	Group 1 (control group): patients were shown a video of a dentist delivering oral hygiene instructions to a 9‐year old girl in a non‐clinical setting Group 2 (test group): patients were shown a modelling video of the same dentist doing a filling with LA, to the same 9‐year old girl, in clinic
Outcomes	ACDAS at baseline, second visit and after video. As ACDAS is not administered following LA, we have not included this in our review VAS: 1: in the waiting area, 2: entering clinic, 3: sitting on dental chair, 4: following dental examination with a mirror, 5: polish or fissure sealant, 6: LA, 7: tooth drilling, 8: extraction. We included parameters 1, 2, 3, and 4 in this review Parents' feedback questionnaire. As this included all treatment and not only delivery of LA, its results were not included in this review
Notes	CONSORT flow chart Declarations of interest: none reported There was a sample size calculation Consent form and ethical approval obtained
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The participants were randomly allocated into intervention (modelling video) and control groups with the aid of computer‐generated random numbers by the statistician (AP)"
Allocation concealment (selection bias)	Low risk	Quote: ".... were entered into sealed envelopes that were opened in sequence in accordance with patient participation"
Blinding of participants and personnel (performance bias)   All outcomes	Low risk	Quote: "All participating children and the dentists providing dental treatment were blinded to the type of video"
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Although it was unclear if the investigator was blinded, children and parents report on anxiety and none of the outcomes includes observation of behaviour by an investigator. For this reason we believe there is no detection bias
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Quote: "On the second visit, five children from the modelling group were excluded, three failed to watch the video, two dropped out; and seven children from the control group were excluded (dropped out), but children who failed to watch the video from the control group were not excluded"
Selective reporting (reporting bias)	Low risk	All recorded outcomes were reported on within the results section
Other bias	Low risk	No further bias identified