Combination of Revascularization and Apexification in the Treatment of an Avulsed Tooth: A Case Report

INTRODUCTION

Anterior teeth are the most common part of the dentition to be traumatized during childhood.^1,2 The frequency of the traumatic injuries to the dentition ranges from 13.8 to 15.1%.^3–5 Depending on the severity of the trauma, concussion, luxation, fracture, or avulsion may occur, leading to necrosis of the pulp tissue and subsequent incomplete root formation in teeth traumatized at a young age.¹ Avulsion accounts for up to 16% of all traumatic injuries to the permanent dentition^3,6 and maxillary central and lateral incisors are most commonly affected.^3,4,6 The peak incidence of avulsion for the maxillary central incisors usually occurs between the ages of 7 years and 10 years.^3,6 Endodontic treatment of permanent necrotic teeth with open apices is difficult and technique sensitive and actually harder than mature teeth given the fact that immature teeth are usually presented with blunderbuss canals and open apices.^1,2 The goal of endodontic therapy is to eliminate pathogens and to prevent infection of the periapical tissues.^7,8 In teeth with open apices, placement and control of filling materials is difficult due to the absence of the apical constriction that helps in containing these materials inside the tooth.^1,2 External inflammatory root resorption or replacement resorption is also common sequalae of dental trauma.⁹ The limiting factor in the successful treatment of avulsed teeth is extraoral time spent outside the mouth. The risk of replacement resorption and inflammatory root resorption is mainly dependent on the duration of time between avulsion and reimplantation.¹⁰ The purpose of this case report is to present and track a case of a 9-year-old girl who presented with an avulsed maxillary central incisor that was left out of the mouth (socket) for more than an optimal length of time and stored in a less than optimal environment before eventual reimplantation. A 4-year recall of the case will show adequate functionality and health and suggests a possible mode of treatment for these types of cases.

CASE DESCRIPTION

A 7-year-old female patient reported to the Department of Endodontics at the University of Southern California School of Dentistry with a chief complaint that she fell on face while she was bike riding and tooth 8 (following Universal Numbering System) was avulsed. The tooth was stored outside the mouth for more than 2 hours in a dry napkin before eventual reimplantation in an emergency room by the on-call resident. There was no reported loss of consciousness or altered mental status following the accident. It was verified through a thorough interview with the patient and the patient’s parents that tooth 8 was completely avulsed, and tooth 9 was subluxated. Tooth 8 was rinsed with saline and replanted. The anterior teeth were splinted. The time between avulsion and reimplantation was confirmed to be more than 2 hours. Clinical pictures were provided by the parents depicting the extent of the injuries (Fig. 1). The patient was referred to the endodontic department for further evaluation and treatment 2 weeks after the trauma. At that time, complete endodontic testing was done. Tooth 8 had no response to cold or electric pulp tester (EPT). The patient had slight tenderness to percussion and palpation with mobility grade +1. Radiographic evaluation showed incomplete root formation with a wide apical foramen (Fig. 2A). Tooth 9 responded normally to cold and EPT testing. The findings, risks, benefits, and alternative treatment options (including no treatment) were discussed with the patient and her parents. The patient’s parents fully understood that tooth 8 had a long-term poor prognosis since it was kept in a dry environment for more than 2 hours before reimplantation. The decision was made to attempt revascularization as a first line of treatment, despite the poor overall prognosis. The patient’s parents consented to the proposed treatment.

The standard strict protocol for revascularization by Law et al. was used.^11,12 All endodontic procedures were performed using rubber dam isolation to assure proper asepsis, using an operating microscope (Carl Zeiss, Oberkochen, Germany), and checked for proper postoperative occlusion at each step. At the first visit, the patient was anesthetized with 2% lidocaine with 1:100,000 epinephrine. Endodontic access was performed, and the pulp verified as being necrotic. The canal was cleaned, residual pulp tissue removed as much as possible, and the canal irrigated using diluted NaOCl. The canal was filled with Ca(OH)₂ as an intracanal medicament and provisionalized with a cotton pellet and Fuji IX glass ionomer. A radiograph was taken to verify the placement of the calcium hydroxide (Fig. 2B). The parents were informed to contact the clinic if complications occurred before the next scheduled appointment and the patient discharged in a stable condition. At the second visit, the patient was doing well with no pain to percussion and palpation. The tooth mobility was within normal limits and the splint was removed. The patient was anesthetized with 3% carbocaine without epinephrine. Endodontic access was performed, and the cotton pellet was removed. The Ca(OH)₂ was irrigated from the canal using 17% EDTA. Bleeding was stimulated in the canal using a hand file, and was controlled at the cementoenamel junction (CEJ); BC putty (Bressler, root repair material) was placed over the blood, followed by a layer of glass ionomer to protect the BC putty. The tooth was then etched and bonded and a composite restoration was placed. A postoperative radiograph was taken (Fig. 2C) and instructions were given. The patient was scheduled for a 3-month follow-up. The parents were again informed to contact the clinic if any complication occurred. At the 3-month recall, a radiograph was taken showing formation of a dentinal bridge at the coronal portion of the canal and continuation of root formation at the apical portion of the root (Figs 2D and E). At the 6-month recall, the patient was asymptomatic (no pain on biting, percussion, or palpation). However, upon clinical examination, a sinus tract was noted and was traced with a gutta percha point to tooth 8 (Fig. 2F). In addition, there was no metallic sound upon percussion on tooth 8 indicating that there was no sign of ankylosed. Upon radiographic examination, there was a degree of root development suggesting that the intended procedure (revascularization) had worked until the canal was infected and that the process of root development ceased at that point. There were also some signs of root resorption. The patient was scheduled for a cone-beam computed tomography (CBCT) scan, which confirmed that the tooth was undergoing resorption (most likely inflammatory); it also elucidated the portion of the tooth that had developed following the regeneration procedure (Fig. 3A). A decision was then made to reopen the tooth, thoroughly clean the canal space, and place Ca(OH)₂ once again for 2 weeks and then reevaluate (Fig. 2G). After 2 weeks with Ca(OH)₂ in the canal, the patient was asymptomatic. There was no pain to percussion, palpation, or bite. Upon clinical examination, the sinus tract had resolved. A decision was then made to perform mineral trioxide aggregate (MTA) apexification. The patient was anesthetized with 2% Lidocaine with 1:100,000 epinephrine. Endodontic access was performed and the Ca(OH)₂ was removed using 17% EDTA and 4% NaOCl irrigation. The canal was dried, and a 4 mm white MTA plug (Dentsply, ProRoot MTA) was placed at the root apex (using a Collacote membrane as an apical barrier to contain the MTA). The MTA was covered with a moist cotton pellet, and the access was sealed with Fuji IX. A radiograph was taken to verify the placement and quality of the MTA plug (Fig. 2H). Postoperative instructions were given, and the patient was discharged in a stable condition. The patient was rescheduled in 2 weeks to continue her treatment. When the patient returned, no anesthesia was given. Access made and the cotton pellet removed. The MTA was verified as being completely set. Irrigation was performed using 17% EDTA and 4% NaOCl. The canal was then dried and obturated with the gutta percha and AH26 sealer using the warm vertical condensation technique. The access was etched and bonded and the tooth restored with a composite restoration. A postoperative radiograph was taken (Fig. 2I), postoperative instructions were given, and the patient was discharged in a stable condition and scheduled for a 6-month recall, with subsequent yearly follow-ups. Treatments were done by two different endodontists; one did the revascularization and the other did the apexification after failure of the first treatment. Figure 2J shows the subsequent 4-year recall with the tooth still in the mouth with a progression of healing. Upon clinical examination at the 4-year recall, the patient was asymptomatic with no pain on biting, percussion, or palpation; no evidence of ankylosis; and no significant mobility. A CBCT scan was taken (Fig. 3B) and showed signs of healing. Clinical pictures were also taken showing slight gray discoloration at the cervical area of tooth 8, which was retained, functional, and otherwise healthy (Fig. 4). A flow diagram of the treatment is provided in Flowchart 1.

DISCUSSION

The prognosis of avulsed teeth depends largely on the duration of time the tooth remains extraorally and how it is stored during that period.^13,14 According to Andreasen, extra-alveolar time and the storage medium are the most important factors related to root resorption. After 60 minutes of dry storage, replacement resorption is very likely. After 30 minutes of dry time, inflammatory resorption is commonly encountered.^13,14 The treatment options vary in the case of an avulsed tooth and can be dependent upon the stage of root formation. Apexification or revascularization procedures are considered as options in the case of an avulsed tooth with an open apex, while conventional root canal treatment is the option of choice in the case of an avulsed tooth with a completely formed apex. Apexification is performed to induce a calcific barrier in a root with an open apex or continued root development of an incompletely formed root in teeth with necrotic pulps.¹⁵ Revascularization is the restoration of the vascular supply to the pulp-dentin complex by triggering bleeding into an empty root canal space similar to a blood clot in surgical wound healing (no use of stem cells or growth factors).¹⁶ Giving the fact that the tooth in this case report was kept outside of the mouth in a dry environment for more than 2 hours, the expected prognosis would traditionally be very poor.^13,14 The decision in this case to attempt revascularization was admittedly untraditional given the adverse set of circumstances. However, it was attempted as a last resort to create root growth and closure and to allow the patient every possibility to retain her tooth. Indeed, in the worst-case scenario, the tooth could be prepared for a decoronation procedure following any failed attempts at revascularization.¹⁷ To this end, the revascularization procedure was done following the strict guidelines described by Law et al. with the exception of the use of BC putty (a bioceramic) instead of MTA.^11,12 Unfortunately, after 6 months of the treatment the procedure had not produced its desired goals and the patient came back with a sinus tract. There are several possible explanations for this failure, which include leakage, but are not limited to microleakage or the restoration. In addition, there is no concrete and accepted protocol for performing regenerative procedures on traumatized teeth. The resorptive processes that often accompany tooth avulsion may indeed be a hindrance to the success of regenerative endodontic procedures. In this case, when the treatment failed, a decision was made to reopen and reclean the root canal system. Fortunately, at that point, since there had been adequate root development to perform apexification predictably (as a result of the revascularization attempt), a decision was made to do apexification using white MTA instead of reattempting revascularization. The MTA is a biocompatible material that has shown to have superior results.^18,19 Its major advantage is that MTA apexification does not require protracted treatment regimens, has superior sealing ability, and better antibacterial properties with a setting time of 3–4 hours with a pH of 12.5. The MTA acts by producing interleukins and cytokines that are released and can lead to the formation of the hard tissue. Currently, MTA apexification appears to be a more predictable procedure than revascularization.^18,19

CONCLUSION

Treatment of an avulsed tooth that has been subjected to less than favorable circumstances (extended extraoral time and severe desiccation) is questionable. In many cases, such teeth are not reimplanted. This case report outlines a method of treatment for such teeth, which may be viable. Revascularization in combination with apexification may potentially be successful in these types of cases. It must be stressed that when doing revascularization, it is important to make sure that there is a tight coronal seal to prevent microleakage that might interfere with the treatment success and that the strict established protocol is followed. Apexification using MTA is a good alternative if revascularization fails or if there is enough root closure to contain the MTA. Additional studies are needed regarding the treatment of avulsed teeth. This case study may provide a viable treatment alternative in a number of clinical situations.

REFERENCE

1. Moore A, Howley M, O’Connell A. Treatment of open apex teeth using two types of white mineral trioxide aggregate after initial dressing with calcium hydroxide in children. Dental Traumatol 2011;27(3):166–173. DOI: 10.1111/j.1600-9657.2011.00984.x.

2. Silveira C, Sebrão C, Vilanova L, et al. Apexification of an immature permanent incisor with the use of calcium hydroxide: 16-year follow-up of a case. Case Rep Dent 2015;2015: 984590.

3. Andreasen J, Ravn J. Epidemiology of traumatic dental injuries to primary and permanent teeth in a danish population sample. Int J Oral Surg 1972;1(5):235–239. DOI: 10.1016/S0300-9785(72)80042-5.

4. Feiglin B. Textbook and colour atlas of traumatic injuries to the teeth: Jens O. and Frances M. Andreasen. Aust Endod J 2010;20(2):20–20.

5. Aldrigui J, Abanto J, Carvalho T, et al. Impact of traumatic dental injuries and malocclusions on quality of life of young children. Health Qual Life Outcomes 2011;9(1):78. DOI: 10.1186/1477-7525-9-78.

6. Janakievski J. Avulsed maxillary central incisors: the case for autotransplantation. Am J Orthod Dentofacial Orthop 2012;142(1):9–17. DOI: 10.1016/j.ajodo.2012.04.010.

7. Anil Kumar G, Anusha T. Single visit apexification with mineral trioxide aggregate. Annals and Essences OF Dentistry 2010;2(3):106–109. DOI: 10.5368/aedj.2010.2.3.106-109.pdf.

8. Vijayran M, Chaudhary S, Manuja N, et al. Mineral trioxide aggregate (MTA) apexification: a novel approach for traumatised young immature permanent teeth. BMJ Case Rep 2013;2013: bcr2012008094. DOI: 10.1136/bcr-2012-008094.

9. Bakland L, Andreasen J. Will mineral trioxide aggregate replace calcium hydroxide in treating pulpal and periodontal healing complications subsequent to dental trauma? A review. Dent Traumatol 2011;28(1):25–32. DOI: 10.1111/j.1600-9657.2011.01049.x.

10. Prabhakar A, Gulati A, Lnu S, et al. Esthetic management of an anterior avulsed tooth: A case report. Int J Clin Pediatr Dent 2009;2(3):35–38. DOI: 10.5005/jp-journals-10005-1016.

11. Law A. Considerations for regeneration procedures. J Endod 2013;39(3):S44–S56. DOI: 10.1016/j.joen.2012.11.019.

12. Hargreaves KM, Law AS. Regenerative endodontics. In: Hargreaves KM, Cohen S. Pathways of the Pulp. ch. 16,St Louis, MO: Mosby Elsevier; 2011. pp. 602–619.

13. Andreasen J, Borum M, Jacobsen H, et al. Replantation of 400 avulsed permanent incisors. 4. factors related to periodontal ligament healing. Dent Traumatol 1995;11(2):76–89. DOI: 10.1111/j.1600-9657.1995.tb00464.x.

14. Andreasen J. Effect of extra-alveolar period and storage media upon periodontal and pulpal healing after replantation of mature permanent incisors in monkeys. Int J Oral Surg 1981;10(1):43–53. DOI: 10.1016/S0300-9785(81)80007-5.

15. Goldstein S, Sedaghat-Zandi A, Greenberg M, et al. Apexification and apexogenesis. N Y State Dent J 1999;65(5):23–25.

16. American Association of Endodontists.Regenerative Endodontics American Association of Endodontists.

17. Malmgren B, Cvek M, Lundberg M, et al. Surgical treatment of ankylosed and infrapositioned reimplanted incisors in adolescents. Eur J Oral Sci 1984;92(5):391–399. DOI: 10.1111/j.1600-0722.1984.tb00907.x.

18. Ham K, Witherspoon D, Gutmann J, et al. Preliminary evaluation of BMP-2 expression and histological characteristics during apexification with calcium hydroxide and mineral trioxide aggregate. J Endod 2005;31(4):275–279. DOI: 10.1097/01.don.0000140584.65320.cc.

19. El Meligy OA, Avery DR. Comparison of apexification with mineral trioxide aggregate and calcium hydroxide. Pediatr Dent 2006;28(3):248–253.