Current Approaches to Pediatric Endodontics

There appears to be a significant overlap between the pediatric and endodontic dental specialties owing to the management of a very high-risk patient base and the treatment of severely compromised teeth. Despite remarkable efforts through preventive programs across the United States, dental caries is still a significant public health problem.¹ According to the U.S. Centers for Disease Control and Prevention, there has been an increased prevalence of total and untreated caries among youth over the last four decades.² A glance at the epidemiology reveals a rising trend for patients seen by pediatric dentists³ and endodontists.⁴ However, there are limited data available regarding the collaborative efforts between these two dental specialities. In private practice, many dentists encounter immature permanent teeth that require complex treatment and demand efficient management. This article seeks to cover the established treatment modalities for the pediatric-endodontic patient, and the current literature on new guidance.

The advancement of biocompatible dental materials established with Torabinejad’s and Chivian’s⁵ paper on mineral trioxide aggregate (MTA) and continued with the development of other successful bioceramic materials⁶ has significantly changed the capabilities of treating teeth with poor prognosis attributed to perforations, persistent apical lesions, extensive decay, and other conditions. Such advances contribute considerably in managing teeth that have not completed root development. Although the concepts of inducing root completion are well established,^7–10 the emphasis should focus on understanding current advances in treatment modalities that overcome several of the past drawbacks.

The emphasis should focus on understanding current advances in treatment modalities

The management of a pulpally involved tooth has proven to be one of the most challenging clinical scenarios,^7,10 and this is further complicated by the lack of root completion in immature teeth. Immature permanent teeth are encountered from the eruption of the permanent central incisor to the completion of root formation in the permanent second molar, establishing the age of patients from 6 to 16 years.¹¹ The initial consideration with pulpally involved immature permanent teeth is patient management, as a majority of the demographic is known to present with significant anxiety and requires effective behavior management strategies.^12–14

Extensive caries in immature permanent teeth and their pulpal consequences are a predominant reason for seeking dental treatment.^2,8 Trauma involving pulp is another common complaint associated with immature permanent teeth, with data documenting almost a third of children experiencing a dental injury by age 14.^8,15,16 Developmental disturbances, such as dens evaginatus/​invaginatus, are less common, but can often present with pulpal involvement.^10,17,18 The ideal management strategy for all of these pulp-involved scenarios involves pulp healing and regeneration, which then allow reparative dentin formation necessary for the continued development of the root and eruption of the tooth.^6–8,19

CLINICAL DIAGNOSIS AND RADIOGRAPHS

A complete and detailed examination is of utmost importance in dental care. Clinical findings and symptoms direct the dentist to an accurate pulpal diagnosis, which, in turn, dictates the plausible treatment options.⁹ However, this can be a considerable challenge in the pediatric population. It has been noted that diagnostic tests conducted on children to determine pulpal status are typically unreliable, and the symptoms may not be accurate with the actual condition of the pulp in immature teeth.⁸ Hence, it is crucial to obtain radiographs of the affected tooth to assess the coronal structure, periapical tissues, furcation area, periodontal ligament space, and the surrounding bone.^8,9 Evaluation of root development may be a vital factor in determining treatment of immature permanent teeth; however, it is necessary to acknowledge the limited scope of a periapical film in identifying the true extent of apical closure.⁷ Another essential detail to consider in young and uncooperative children is the potential inability to obtain a periapical radiograph, and having to manage with only a bitewing radiograph.⁸

TREATMENT MODALITIES BASED ON DIAGNOSIS

The American Academy of Pediatric Dentistry (AAPD) guidelines for treating immature vital teeth diagnosed with reversible pulpitis include pulp capping, partial pulpotomy and apexogenesis procedures.^8,9 A clinician should be able to make a sound judgement regarding the pulp therapy procedure and medicament that is appropriate for the patient based on the diagnosis, medical history, extent of caries/​pulpal involvement, restorability of the tooth, child’s behavior, follow-up compliance, and long-term prognosis.^8,9

Pulp capping, partial pulpotomy and apexogenesis procedures allow for preservation of pulp vitality, which, in turn, enables continued root development, apical closure, and formation of secondary dentin in the radicular region of the immature tooth.^8,9 These procedures essentially utilize calcium hydroxide, which offers proven long-term success, or MTA, which ensures a more predictable dentin bridge formation and pulpal health.^8,9,20 Additionally, in a comparison of alternative coronal barrier materials and MTA in vital pulp treatment, Miller et al²¹ discussed the advantage of using newer biocompatible materials that offer excellent odontoblastic potential, with the ability to form calcium hydroxide and hydroxyapatite. However, it must be noted that data published on calcium hydroxide pulpotomies have consistently reported a high success rate.^9,21 Recommendations for the restorative material are a glass ionomer cement layer, followed by a final composite or amalgam restoration, and documentation with bitewing and periapical radiographs.^7,9 Follow-up at two weeks without manifestation of adverse signs and symptoms is a good indication of success, as most failures tend to present within this time frame.^22,23

According to the AAPD, non-vital pulp treatments for immature permanent teeth diagnosed with irreversible pulpitis or necrotic pulp include apexification.⁹ This is performed to induce apical closure and obtain an apical seal in immature permanent teeth that present either with a blunderbuss apex or an apex with parallel walls.⁸ The procedure allows obturation with gutta-percha at a later stage. A calcium hydroxide apexification procedure usually requires multiple appointments, depending on the stage of root development.^19,24 An alternative is to utilize MTA to form an apical barrier, as it provides the advantage of fewer appointments, shorter chairtime, and better results.^19,24 Studies on MTA apexification document up to a 94% success rates, thereby proving to be superior to calcium hydroxide apexification.^8,9,19 After achieving apical closure, the root canal can be traditionally obturated with gutta-percha; alternatively, MTA or composite resin can be used to fill thin canals to prevent root fracture.⁹

Immature permanent teeth have thin-walled roots with open apices and roots that are not yet full length.^7,8,10 The concerns with apexification arise from the inability of the procedure to promote further development of the root and improve thickness of the canal walls, leaving the immature tooth susceptible to cervical root fractures.^7,10,18,24 The large dentinal tubules present in immature teeth are also more permeable to bacterial infection and, oftentimes, concerns related to long-term prognosis present extraction as the preferred treatment option in pediatric patients.⁷

Regenerative or revascularization pulp treatments are now considered the preferred choice for treating non-vital immature teeth.^{6,10,18,19,24} These procedures not only allow continued formation of the root to its full length (leading to a favorable crown-to-root ratio, they also support formation of adequate thickness of secondary radicular dentin with closure of the apex.^{6,8,18,19,25,26} The presence of vital tissue in revascularized teeth enhances the capacity to elicit an immune system response and signal tissue damage through nociceptors.^6,19

Regeneration procedures were first discussed in the work of Banchs and Trope²⁷ and Iwaya et al,²⁸ who outlined case reports establishing success. Later, Lovelace et al²⁹ demonstrated regenerative success through the influx of mesenchymal stem cells containing blood from beyond the apex into the disinfected root canal system. The growth factors present in the blood clot promote differentiation of the stem cells into odontoblasts, which can lay down dentin and continue root development.^7,8,16,19

The majority of current literature on regenerative endodontics in immature permanent teeth corroborates a successful increase in root length and width after completion of these procedures.^6,18,25,26 Compared to apexification with MTA and calcium hydroxide, regenerative procedures showed an improved success rate in relation to root length and width.^6,18 Regenerative procedures have also demonstrated unparalleled resolution of apical periodontitis at a rate of more than 90%, with the benefit of reliable positive pulp sensitivity tests.⁶ Furthermore, regenerative procedures promote nociception, which is a valuable response, as it primarily functions as a protective mechanism against damage. It also serves a good indicator of the presence of healthy vascularized tissue.^6,19

Several studies establish three major objectives for achieving successful regeneration and root maturation.^10,16,25 First is the elimination of microbes from the canal space. Regenerative endodontic treatment begins with disinfection using copious irrigation of the canal space with sodium hypochlorite, followed by placement of a triple antibiotic paste in the dried canal space. This antibiotic paste contains ciprofloxacin, metronidazole and minocycline, and has proven to induce complete removal of microbes after 48 hours of application, along with penetration of the antibiotic into dentin.³⁰ Second is the formation of a scaffold that supports in-growth of new tissue. The procedure is continued in the next appointment by inducing bleeding into the canal through over-instrumentation, which allows the subsequent formation of a beneficial blood clot. The third major objective is creation of a microbe-tight seal to avoid reinfection of the canal space. The procedure is completed by placing an MTA plug, covered by a layer of glass ionomer cement and a final restoration.^10,16,25

A concern with using the triple antibiotic paste is its effects on stem cell survival. Therefore, it is recommended to use it in lower concentrations (less than 1 mg/​ml) that still allow the paste to maintain its antimicrobial action.²⁵ Similar issues have been noted with sodium hypochlorite, which, at full concentration, can lead to denaturation of growth factors present in dentin and contribute to a negative effect on stem cells.^16,25 This has led to utilizing 1.5% sodium hypochlorite alongside 17% ethylenediaminetetraacetic acid.^6,16,25 A major concern associated with regenerative procedures is tooth discoloration.^10,16,26,31 The use of minocycline in the antibiotic paste and MTA during the procedure has been implicated as the major causes for tooth discoloration.¹⁰ Other potential causes include the deposition of blood pigments and breakdown products in dentinal tubules, inadequate removal of pulpal remnants, unsatisfactory cleansing of the access cavity, and placement of MTA coronal to the cementoenamel junction.¹⁰ Several mitigation strategies have been employed to overcome esthetic concerns, but have not yet proven completely successful.^10,16 Currently, discolored teeth are successfully treated with routine bleaching methods and exhibit significant improvement esthetically.^10,26 Concurrently, these concerns may pave the way for alternative materials, such as bioceramics, to be utilized in regenerative endodontics.^22,26 

Failure has been reported with this regenerative protocol, and it has been primarily attributed to inadequate disinfection, failed restorations or root fracture.^26,31 The systematic reviews by Kim et al²⁶ and Tong et al³¹ have argued that root maturation is not entirely predictable, and highlight the potential for publication bias associated with reporting of successful cases. 

Regenerative or revascularization pulp treatments are now considered the preferred choice

Another theme noted in literature discusses the histology of the canal contents after completion of the regenerative procedure.^16,26,32 The introduction of various types of cells, such as cementoblasts, into the root canal system has led to the formation of hard tissue structure in the pulp, which may be problematic.²⁶ Published data confirm a 62% incidence of calcifications in the root canal area of teeth treated with revascularization protocols.^33,34 The studies published by Nakashima et al^32,35 on mobilized dental pulp stem cells using transplantation tissue obtained from other extracted teeth may address this issue; but, with a significant lab aspect associated with managing stem cells, it is yet to translate to routine clinical practice. Further research into regeneration has considered the use of adjuncts, such as platelet rich plasma^34,36 and platelet rich fibrin.³⁷ At present, the literature concludes that more comprehensive studies are required to understand the long term success of regenerative procedures.^32,34–36

INFORMED CONSENT AND BEHAVIOR MANAGEMENT

Successful management of pediatric patients involves understanding and managing the expectations of parents/​caregivers.¹⁴ It is essential to establish effective communication and a good relationship with the parent and child.¹⁴ Effective communication is important while obtaining informed consent for any procedure, especially for regenerative procedures that can present esthetic complications.^14,16 The parent/​caregiver needs to be made aware of the number of appointments required for the completion of procedure, and the reason/​expectations for the visits.^14,16 A detailed discussion regarding the antibiotic paste and potential allergies is necessary.¹⁶ The possibility of tooth discoloration and other adverse effects should be discussed to ensure complete understanding.¹⁶ An in-depth conversation about the risks and benefits associated with proposed treatment and the available alternatives is mandatory.

It is worthwhile to note that dentists encounter a multitude of challenging behaviors while providing pediatric treatment. Several adverse behaviors can be attributed primarily to fear, anxiety and past dental experiences.^10,12,14,38 It is paramount to identify and resolve a child’s adverse behavior to ensure accomplishment of necessary treatment.^10,14,38

CONCLUSION

It is reasonable for clinicians to anticipate behavioral challenges in children presenting for pulp therapy. Such challenges can emanate from the child’s age, temperament, and especially any physical/​emotional trauma associated with the incident prompting treatment.^10,14,38 Clinicians should be prepared to provide meticulous treatment and exceptional behavior management. It is necessary for practitioners to pursue additional training in identifying patterns of behavior and adapting strategies to neutralize adverse behaviors.^10,38

Basic behavior management strategies reinforced with nitrous oxide/​oxygen inhalation are remarkably effective.^10,38 A clinician should be knowledgeable and confident in employing strategies such as tell-show-do, voice control, nonverbal communication, positive reinforcement and distraction.³⁸ Furthermore, operators should have an effective guidance protocol in the event a child’s behavior poses challenges to safely accomplishing treatment. The provider should have access to resources and referrals that will facilitate use of advanced behavior management techniques.³⁸ A collaborative approach is necessary and can include general dentists, pediatric dentists, endodontists, anesthesiologists and/​or other providers. Collaborative treatment will translate to successful management of immature permanent teeth, the patient, and the parent/​caregiver.¹⁴ 

KEY TAKEAWAYS

• Advances in biocompatible dental materials have significantly changed the capabilities of treating teeth with a poor prognosis attributed to perforations, persistent apical lesions, extensive decay, and other conditions. 
• Such advances contribute considerably in managing pediatric patients with teeth that have not completed root development.
• The ideal management strategy for the pulp-involved scenarios described in this paper involves pulp healing and regeneration — which then allow reparative dentin formation necessary for the continued development of the root and eruption of the tooth.^6–8,19
• Pulp capping, partial pulpotomy and apexogenesis procedures allow for preservation of pulp vitality, which, in turn, enables continued root development, apical closure, and formation of secondary dentin in the radicular region of the immature tooth.^8,9
• According to the American Academy of Pediatric Dentistry, non-vital pulp treatments for immature permanent teeth diagnosed with irreversible pulpitis or necrotic pulp include apexification.⁹
• In today’s practice, regenerative or revascularization pulp treatments are considered a top choice for treating non-vital immature teeth.^{6,10,18,19,24}

REFERENCES

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The authors have no commercial conflicts of interest to disclose.

From Decisions in Dentistry. April 2021;7(4):14, 16-18.