Endodontic treatments on permanent teeth in pediatric patients aged 6–12 years old

Abstract

Backgroud/purpose

The prevalence of carious lesions and traumatic injury in individuals between ages 6 and 12 is high. This study aimed to characterize pediatric patients aged 6–12 treated in the endodontic clinic and investigate the prevalence and patterns of their provided endodontic treatments.

Materials and methods

Clinical and radiographic records of patients (ages 6–12) referred to the postgraduate Endodontics clinic from June 2017 to June 2020 were reviewed. Demographics, pre-and post-operative conditions, type of endodontic treatment, and behavioral management were collected.

Results

A total of 6350 teeth from 6089 patients were treated in this period, and 425 teeth (6.7%) from 405 patients were included. Ages 9–11 were the most commonly treated age group. Significantly more lower molars (41.9%) and upper anterior teeth (36.7%) were treated (P < 0.05). The majority of teeth were diagnosed with pulp necrosis (39.5%), and the most common periapical diagnosis was normal apical tissues (39.8%), then symptomatic apical periodontitis (38.8%). The most common etiological factor was caries (63.5%). Two hundred six teeth (48.5%) were treated with root canal therapy, 161 teeth (37.9%) with vital pulp therapy, 46 teeth (10.8%) with apexification or regenerative endodontic procedure, 12 teeth (2.8%) with non-surgical retreatment. A statistically high number of patients (87.8%) tolerated the endodontic procedures without any sedation (P < 0.0001).

Conclusion

Pediatric patients aged 6–12 compose around 7% of the population treated at the postgraduate Endodontics clinic, reflecting the high demand for endodontic treatment in a pediatric mixed dentition population.

Introduction

Endodontic treatment aims to prevent and intercept pulpal/periradicular pathosis and preserve the natural dentition when affected by pathosis, which ultimately allows for the proper function of the dentition.¹ These purposes play a pivotal role in mixed dentition during key formative years, influencing the future quality of life.² Endodontic treatment in children (below 16 years of age) with primary and permanent teeth can be as prevalent as up to 9.6%. Among their root canal-treated teeth, permanent teeth were 69.8%.³ Ridell et al.⁴ reported that almost 9% of 19-year-olds have at least one endodontically treated tooth, and about 20% had their endodontic treatment performed between 10 and 13 years of age despite organized regular free dental health services in Sweden. Considering that the prevalence of carious lesions and traumatic injury in a pediatric population is high, it is important that endodontists understand their roles and tools to treat these growing patients in need of endodontic care.

A child's behavior between ages 6 and 12 starts to change notably regarding emotional and social cognition⁵ and develops an increasingly independent relationship with parents.⁶ Furthermore, individuals from this age group begin to acquire and fine-tune motor skills critical in allowing them to perform the hygiene practices that can help prevent caries development.⁷ This age group is also highly susceptible to traumatic injuries for the following reasons: 1) increasing participation in physical activities, 2) enrolling in school, and 3) growing involvement in team sports.⁸ Dental caries and dental trauma in this age group have been generally reported to be the significant and most common causes to affect the health of dental pulp and consequently cause pulpal infection and periapical diseases.^3,9 Hence, investigating this unique group of individuals is critical to properly managing their good oral health and predicting the need for endodontic treatment.

Endodontists can uphold the objectives of treating this particular patient population with treatment options, such as vital pulp therapy (VPT), root canal therapy (RCT), apexification/regenerative endodontic procedure (Apex-Regen), non-surgical retreatment (NSRetx), or surgical retreatment (SurgRetx). To obtain pediatric patients' cooperation and facilitate endodontic treatment in some cases, pharmacological behavior management, including nitrous oxide, conscious sedation, and general anesthesia, can be provided. These types of advanced behavior management minimize the patient's fear and anxiety, thus decreasing the likelihood of significant disruptive behaviors.¹⁰

Recognizing the need for endodontic treatment within this specific age group is the first step in shifting the views of endodontists toward treating this patient population; knowing the range of treatment options and the adjuncts available to facilitate their care can instill confidence in both providers and patients. Thus, the purposes of this retrospective study were to characterize pediatric patients with mixed dentition treated in the endodontic clinic and investigate the prevalence and patterns of their endodontic treatments.

Materials and methods

Patient records

This study was approved by the Institutional Review Board (IRB) Committee at the University of Pennsylvania (IRB Protocol #844031). An electronic chart search using axiUm software (Exan, Henry Schein Inc, Melville, NY, USA) of all patients treated by residents at the University of Pennsylvania Endodontic clinic (UPenn Endo) between June 2017 to June 2020 was performed. Inclusion criteria included: 1) patient age of 6 to 12 years old at the time of treatment, 2) pre-and post-operative clinical condition and radiographs recorded, and 3) detailed demographics. The following data were collected and analyzed from each patient included in the study: gender, age, tooth type, pulpal and periapical diagnoses, reasons for treatment, and whether sedation was utilized. Treatments rendered on the permanent teeth of these patients were: VPT, RCT, NSRetx, Apex-Regen, or SurgRetx. Three age groups were delineated: 6–8 years old, 9–11 years old, and 12 years old. The permanent tooth type treated was categorized into upper anterior, upper premolar, upper molar, lower anterior, lower premolar, and lower molar. Pulpal and periapical diagnoses followed the American Association of Endodontists’ diagnostic terminology.¹¹ Pulpal diagnoses include normal pulp, reversible pulpitis, symptomatic irreversible pulpitis, asymptomatic irreversible pulpitis, pulp necrosis, previously initiated therapy, and previously endodontically treated. Periapical diagnoses include normal apical tissues, symptomatic apical periodontitis, asymptomatic apical periodontitis, acute apical abscess, and chronic apical abscess. Etiology was determined to be one of the following: caries, trauma, anatomical abnormalities, or other, which included any suspected origin of pathology not accounted for by the former three categories. Behavioral management information recorded consisted of whether nitrous oxide was utilized for the endodontic treatment.

Statistical analysis

Statistical analysis of the data in each category (gender, age, tooth type, pulpal and periapical diagnoses, reasons for treatment, and sedation use) was performed using IBM SPSS Statistics Version 23 (IBM Corp, Armonk, NY, USA). Chi-square test was used to analyze the data, and Mann-Whitney test and Kruskal-Wallis test were used to analyze the difference between sex, age, and treatment type for sedation. The statistical significance level was set at P = 0.05.

Results

A total of 6089 patients (6350 teeth) were treated at UPenn Endo from June 2017 to June 2020. Among them, 6- to 12-years-old 405 patients (425 teeth) were included in this study. The study population comprised 6.7% of all patients treated during the selected study period. The percentage of patients (ages 6–12) among treated patients was consistently around 7% every year (Fig. 1A). Each type of endodontic procedure also maintained a steady percentage each year during the period under review. The proportions of RCT and NSRetx treated in 6- to 12-year-old patients were 4.72% and 1.56%, respectively. However, the proportions of VPT and Apex-Regen treated in 6- to 12-year-old patients were 40.4% and 72.6%, respectively, indicating VPT and Apex-Regen were performed mainly for these young pediatric patients (Fig. 1B).

Fig. 1.

(A) Endodontic treatments performed in patients between 6 and 12 years of age and patients over 12 years of age from June 2017 to June 2020. (B) Distribution of endodontic treatments performed in patients between 6 and 12 years of age and patients over 12 years of age. RCT, root canal treatment; NSRetx, non-surgical retreatment; VPT, vital pulp therapy; Apex-Regen, apexification or regenerative endodontic procedure; SurgRetx, surgical retreatment.

For permanent teeth of pediatric patients aged 6–12, most treatments comprised RCT (n = 206, 48.5%) and VPT (n = 161, 37.9%). 10.8% (n = 46) of the endodontic treatment was Apex-Regen, and 2.8% (n = 12) was NSRetx (Fig. 2A). There was no tooth treated by SurgRetx. In contrast, approximately 70% of patients over 12 years of age were treated by RCT. NSRetx and SurgRetx were rendered for 15% and 9% of these patients, respectively (Fig. 2B).

Fig. 2.

(A) Endodontic treatment modality for patients between 6 and 12 years of age. (B) Endodontic treatment modality for patients over 12 years of age. RCT, root canal treatment; NSRetx, non-surgical retreatment; VPT, vital pulp therapy; Apex-Regen, apexification or regenerative endodontic procedure; SurgRetx, surgical retreatment.

The detailed demographic characteristics of the study subjects are summarized in Table 1. Among those pediatric patients who received endodontic treatment, 205 (50.6%) were males, while 200 (49.4%) were females with a mean age of 10.2 ± 1.51 years. In terms of treatment modality, there was no statistical difference between males and females. Of the 405 patients in the study, 63 patients (15.5%) were of the age group 6 to 8, and 245 patients (60.5%) were of ages 9 to 11, which is statistically higher than the other two age groups (P < 0.0001), and 97 cases (24%) were of age 12. Except for NSRetx, all treatment modalities were rendered to the patients of ages 9 to 11 statistically more than other age groups. No patient under age 8 received NSRetx, which suggests that this age group has fewer erupted permanent teeth and no need for repeated endodontic treatment. Regarding Apex-Regen, most treated age groups were 6 to 8 (38.7%) and 9 to 11 (56.8%), indicating Apex-Regen was rendered for more immature necrotic permanent teeth.

Table 1.

Patient demographic and baseline characteristics.

	All Teeth (n = 425)	P value	VPT (n = 161)	P value	RCT (n = 206)	P value	NSRetx (n = 12)	P value	Apex-Regen (n = 46)	P value
Sex	n (%)	0.771	n (%)	0.88	n (%)	1	n (%)	0.39	n (%)	0.054
Male	205 (50.6)		75 (48.7)		96 (49.7)		4 (33.3)		30 (65.2)
Female	200 (49.4)		79 (51.3)		97 (50.3)		8 (66.7)		16 (34.8)
Age (years ± SD)	10.2 ± 1.51		9.98 ± 2.26		10.63 ± 1.29		11.41 ± 0.67		9.17 ± 1.30
Age group (years)		<0.0001		<0.0001		<0.0001		1		<0.0001
6 to 8	63 (15.5)		35 (22.7)		11 (5.3)		0 (0)		17 (38.7)
9 to 11	245 (60.5)		88 (57.1)		126 (64.1)		6 (50)		25 (56.8)
12	97 (24)		31 (20.2)		58 (30.6)		6 (50)		2 (4.5)
Tooth Type		<0.0001		<0.0001		<0.0001		0.472		<0.0001
Upper Ant	156 (36.7)		24 (14.9)		86 (41.7)		5 (41.7)		41 (89.1)
Upper Premolar	3 (0.7)		2 (1.3)		0 (0)		0 (0)		1 (2.2)
Upper Molar	72 (16.9)		35 (21.7)		35 (17)		2 (16.7)		0 (0)
Lower Ant	10 (2.4)		1 (0.6)		8 (3.9)		0 (0)		1 (2.2)
Lower Premolar	6 (1.4)		2 (1.3)		3 (1.5)		0 (0)		1 (2.2)
Lower Molar	178 (41.9)		97 (60.2)		74 (35.9)		5 (41.7)		2 (4.3)
Pulpal Dx		<0.0001		<0.0001		<0.0001		N/A		<0.0001
NP	18 (4.2)		15 (9.3)		3 (1.5)		0 (0)		0 (0)
RP	90 (21.2)		87 (54)		2 (1)		0 (0)		1 (2.2)
SIP	88 (20.7)		34 (21.1)		54 (26.2)		0 (0)		0 (0)
AIP	28 (6.6)		16 (9.9)		12 (5.8)		0 (0)		0 (0)
PN	168 (39.5)		7 (4.4)		122 (59.2)		0 (0)		39 (84.8)
PIT	17 (4)		2 (1.3)		13 (6.3)		0 (0)		2 (4.3)
PET	16 (3.8)		0 (0)		0		12 (100)		4 (8.7)
Periapical Dx		<0.0001		<0.0001		<0.0001		0.343		0.032
NAT	169 (39.8)		122 (75.8)		38 (18.5)		2 (16.7)		7 (15.2)
SAP	165 (38.8)		34 (21.1)		107 (51.9)		4 (33.3)		20 (43.5)
AAP	64 (15.1)		5 (3.1)		44 (21.4)		5 (41.7)		10 (21.7)
AAA	6 (1.4)		0 (0)		6 (2.9)		0 (0)		0 (0)
CAA	21 (4.9)		0 (0)		11 (5.43)		1 (8.3)		9 (19.6)
Etiology		<0.0001		<0.0001		<0.0001		0.174		<0.0001
Caries	270 (63.5)		139 (86.3)		119 (57.8)		6 (50)		6 (13)
Trauma	138 (32.5)		22 (13.7)		78 (37.9)		1 (8.3)		37 (80.4)
Anatomical abnormalities	2 (0.5)		0 (0)		1 (0.5)		0 (0)		1 (2.2)
Others	15 (3.5)		0 (0)		8 (3.8)		5 (41.7)		2 (4.4)

VPT, vital pulp therapy; RCT, root canal treatment; NSRetx, non-surgical retreatment; Apex-Regen, apexification or regenerative endodontic procedure; NP, normal pulp; RP, reversible pulpitis; SIP, symptomatic irreversible pulpitis; AIP, asymptomatic irreversible pulpitis; PN, pulp necrosis; PIT, previously initiated therapy; PET, previously endodontically treated; NAT, normal apical tissues; SAP, symptomatic apical periodontitis; AAP, asymptomatic apical periodontitis; AAA, acute apical abscess; CAA, chronic apical abscess. The statistical significance level was set at p = 0.05.

The most commonly treated tooth types were lower molars and upper anterior teeth, at the frequency of 41.9% and 36.7%, respectively (P < 0.0001). It was noticed that a greater proportion of treated teeth in the Apex-Regen group were upper anterior teeth (89.1%) compared to other treatment groups, which relates to the higher incidence of traumatic dental injuries to upper anterior teeth and causes of their pulp necrosis. Regarding pre-operative diagnosis, pulp necrosis was statistically higher than other pulpal diagnoses in the RCT (59.2%) and Apex-Regen (84.8%) groups. However, the VPT was the primary treatment option for cases with reversible pulpitis (54%). Most teeth diagnosed with symptomatic apical periodontitis were treated by RCT (51.5%) or Apex-Regen (43.5%). The corresponding reasons for endodontic treatment include caries (63.5%) and trauma (32.5%) which are significantly more likely to be the reason for treatment compared to anatomical abnormalities or other reasons (P < 0.0001). There were two lower premolars with dens evaginatus treated by RCT and Apex-Regen, respectively.

Table 2 shows the need for behavioral management for pediatric patients with mixed dentition to undergo endodontic treatments. A high number of patients (n = 360, 88.8%) could tolerate the endodontic procedures without any sedation (P < 0.0001). There was no statistically significant difference between male and female patients (P = 0.87). The age and treatment type showed significant differences (P = 0.001 and 0.003, respectively).

Table 2.

Need for sedative management undergoing endodontic treatments.

	No Sedation	Sedation	P value
Sex	n (%)	n (%)
Male	178 (49.4)	27 (60)	0.87
Female	182 (50.6)	18 (40)
Age (years)
6–8	46 (12.7)	17 (32.7)	<0.001
9–11	218 (60.5)	25 (48.1)
12	96 (26.8)	3 (19.2)
Tx type
RCT	186 (49.9)	20 (38.5)	0.003
NSRetx	12 (3.2)	0 (0)
VPT	142 (38.1)	19 (36.5)
Apex-Regen	33 (8.8)	13 (25)

RCT, root canal treatment; NSRetx, non-surgical retreatment; VPT, vital pulp therapy.

Apex-Regen, apexification or regenerative endodontic procedure.

The statistical significance level was set at p = 0.05.

Discussion

The need for endodontic treatment in pediatric patients will grow with the eruption of permanent teeth and increase the risk of dental caries and trauma. The aims of endodontic treatment for young permanent teeth are to preserve the vitality of pulp tissue and encourage continued root development or to alleviate pulpal infection and prevent apical periodontitis for continuous tooth eruption. The Swedish study collected dental records and radiographs of all 19-year-olds and revealed that endodontic treatment had been performed in 9.1% of patients.¹² A recent study that included children aged 2–16 years treated in the Pediatric Dentistry unit of a hospital reported that 9.6% of patients received endodontic treatments in their primary or permanent teeth.³ In the present study, around 7% of treated patients at the postgraduate Endodontic clinic belonged to the patient population aged 6 to 12 in the mixed dentition stage. The pattern of endodontic treatment for these young pediatric patients was RCT (48.5%), VPT (37.9%), Apex-Regen (10.8%), and NSRetx (2.8%). To our knowledge, this study is the first comprehensive study to access the endodontic status of young permanent teeth of patients (ages 6–12) and shows a significant need for endodontic treatment in these pediatric patients.

In a previous study, RCT was the most common endodontic treatment (70.9%) performed, followed by apexogenesis and apexification (23.0%) in children's permanent teeth. Only 4.3% of cases were treated with pulp capping.³ In our study, on the contrary, 48.5% of patients received RCT, and VPT was the second most frequent endodontic treatment (37.9%), which demonstrated that clinicians preferred to provide less invasive procedures and preserve the vitality of the pulp. The condition of the pulp tissue plays a decisive role in the outcome of conservative VPT.¹³ In a clinical setting, the accurate assessment of the pulp status is one of the greatest challenges for clinicians. In the postgraduate endodontic clinic, all cases are conducted using a dental operating microscope, allowing clinicians to carefully examine the existing pulp's condition and complete caries excavation. Regenerative endodontic procedure (REP) is an emerging biologically based technique for immature necrotic permanent teeth. REP improves root maturation and thickening of the dentin walls, which causes better long-term survival than traditional apexification techniques.¹⁴ Popoola's group reported only 5 cases (1.8%) treated by REP^3, whereas Apex-Regen was rendered in 10.8% of cases in this study. Apexification was performed in seven teeth, and REP was performed in thirty-nine. REP has been provided in most immature necrotic teeth, except for the cases requiring post-placement due to a severely damaged crown. Recently, the systemic analysis revealed that REP in all included studies was performed using a surgical operating microscope.¹⁵ In this context, the treatment providers might have influenced the results, and the external validity of the studies as operator experience is a crucial factor when it comes to outcomes in endodontics.^16,17 Collectively, these findings demonstrated that the selection of treatment options might depend on treatment providers.

Nitrous oxide in oxygen (N₂O/O₂) inhalation sedation is a commonly used form of pharmacological behavior management in pediatric dentistry. N₂O/O₂, when used in combination with oral sedatives, may produce from minimal to deep sedation or general anesthesia.^18,19 A prospective study conducted in a hospital dentistry setting revealed that 93% of anxious pediatric patients completed treatment using N₂O/O₂ sedation.²⁰ Furthermore, a retrospective study reported that 94% of behavior-challenging children successfully received RCT on permanent teeth under 50%/50% N₂O/O₂ sedation with midazolam in combination with meperidine or hydroxyzine.²¹ Interestingly, our study revealed that around 90% of young pediatric patients tolerated endodontic treatments without utilizing sedation techniques. In a university clinic setting, pediatric residents help give local anesthesia to a child with a fear of needles before starting endodontic treatment, possibly reducing the need for sedation in the present study. Overall, N₂O/O₂ sedation should be considered the first choice for sedative management. An interdisciplinary approach with pediatric dentists and endodontists is fundamental to success when providing endodontic treatment for behavior-challenging children.

Dentists are often exposed to children's anger, crying, and a wide range of avoidance behaviors, possibly giving them more stress and tension. The increase in stress may affect the dentists' performance and can be a significant threat to the physical and mental health of the patients.^22,23 A survey study with dentists demonstrated that anesthesia injection for an anxious child led to the highest stress levels.²⁴ Interestingly, performing a pulpectomy induced the highest stress level among dental practices. Pediatric dentists had significantly lower stress than general dentists and residents, demonstrating the educational needs of the general and specialized students regarding the implementation of stress control programs for the fields associated with children. According to a recent survey study, 13% of endodontist responders do not provide endodontic treatment to children.²⁵ Considering the high need for endodontic treatment in this population, it is not deniable for endodontists to accept young pediatric patients and improve their behavior management. Furthermore, endodontics procedures inevitably require an anesthetic injection and often necessitate extended treatment time and multiple visits. Another study showed that dentists with higher anxiety and stress levels were more likely to report changes in their clinical methods.²⁶ Taken together, there is both a need for postgraduate training in sedation techniques and the necessity to train further endodontists to undertake endodontic procedures for pediatric patients, which results in increased self-confidence to obtain an anxious child's cooperation in endodontic procedures and perform a planned treatment.

In the present study, some subjects might be omitted during data collection. There are cases performed under general anesthesia in an inpatient setting and the operating room at a regional children's hospital. General anesthesia is mainly utilized for pediatric dental patients with complex medical/physical/mental conditions or a need for extensive treatment.^27,28 Moreover, a planned endodontic treatment often cannot be performed as a tooth becomes unrestorable due to a long waiting list for treatment in the operating room, which is one of the problems inherent to dental treatment in a hospital setting.²⁸ Most pediatric dentistry patients with an ASA classification of I or II are treated on an outpatient basis with mild to moderate sedation. Thus, the actual number of unnoticed cases might not be significant.

There are potential limitations of the present study. The outbreak of the global COVID-19 pandemic caused unforeseen challenges that affected the regular day-to-day operations of the endodontic clinic. Its normal operation had been suspended for two months due to high risks of exposure and unknown developing factors related to Covid-19. Only patients with severe emergencies received immediate on-site treatments in the clinic during this period. Most patients were managed by teledentistry. Therefore, the overall number of patients from June 2019 to May 2020 is lower than from June 2017 to May 2018 and from June 2018 to May 2019 (Fig. 1A). To consider the unusual circumstances limiting clinical operations, patients’ data were collected from June 2019 to June 2020 instead of June 2019 to May 2020.

Moreover, there is a lack of consideration for the entire dentition of the patients in this study. The patients were referred internally from the Pediatric Dentistry Clinic at UPenn or externally from private practices with a referral letter describing when a specific tooth requires endodontic treatment. However, comprehensive examinations were not conducted for those externally referred patients. This study did not evaluate the mean number of erupted permanent teeth and their frequency of endodontic treatment needs. Therefore, further studies are required to investigate the frequency of endodontic-treated teeth and possible relationships with the characteristics and environment of patients and their parents.

In conclusion, our data revealed that pediatric patients aged 6–12 years old comprise 6.7% of the patient population attending the postgraduate Endodontic clinic, reflecting the high demand for endodontic treatment in a pediatric mixed dentition population. RCT and VPT were the most common treatments rendered for these patients. Around 11% of patients required sedation for behavior management, which suggests a need for further postgraduate training in sedation techniques and the necessity to train endodontists to manage patient behavior and achieve optimal patient care results.

Declaration of competing interest

The authors have no conflicts of interest relevant to this article.