A2 ENDO TRIBUNE Dental Tribune Middle East & Africa Edition | 3/2021 Autogenous transplantation followed by conservative root canal therapy Three years follow-up By Dr Jenner Argueta, Guatemala functional Introduction Although the final goal of the en- is to provide dodontic therapy symptom-free teeth with healthy periapical tissue long term,1 the severely damaged struc- ture sometimes does not allow the clinician to succeed in the pur- suit of saving natural teeth. In these sce- narios, alternative treatments such as crown lengthening, autogenous trans- plantation or even implant placement should be considered with the objective of maintaining oclusal stability and functionality.2, 3 Autogenous transplantation refers to the repositioning of a tooth to another extraction site in the same patient; this can also apply to a tooth replanted into a surgically formed recipient site.4 In the past decades, the success rate reported for this procedure has increased in studies evaluation periodontal tissue heal- ing and radicular resorption. The success rate reported in cases with complete root formation is 84%, and the success rate in teeth with non- complete root formation reaches 94%.5,6 The most significant factor related to the success rate is the vi- ability of the periodontal ligament attached to the root surface of the transplanted tooth; the viability of the periodontal membrane on the radicular surface will decrease after 18 minutes of extra-oral time.7,8 This procedure tends to be technique- sensitive; operator skills and experi- ence will play a crucial role in a suc- cessful outcome. The transplanted tooth often pre- sents with the crown structure to- tally intact. A large percentage of this cases will need root canal therapy; however, the removal of tooth struc- ture needed for access cavity prepa- ration and root canal shaping may undermine the strength of the tooth under functional load.9 Recently, conservative endodontic approach- es have been recommended to mini- mise tooth structure removal and to preserve the very important pericer- vical dental tissue. Among the different developments in dentistry that have made possible conservative approaches in endo- dontic practice are flexible endo- dontic files with controlled memory alloy and enhanced cyclic fatigue re- sistance, visual magnification, bioac- Fig.1: Severely destroyed maxillary first molar with an old amalgam restoration, previous root canal therapy and recurrent caries. tive endodontic sealers, and sonic and ultrasonic irrigant activators.9–11 The development of these technolo- gies has been crucial for making the conservative endodontic approach possible, prioritising the preserva- tion of dentine, especially in the cer- vical region.12 do the root canal therapy during the first two weeks, because of the risk of causing additional injury to the peri- odontal ligament, and it is advisable to proceed with the root canal ther- apy just after two weeks postopera- tively in order to decrease the risk of inflammatory root resorption.6 Case report A 16-year-old female patient was referred to the office for evaluation of tooth #16 (Fig. 1). The referring dentist asked that we apply all the available resources to save the tooth. The diagnosis was previously treated and symptomatic periapical peri- odontitis. After detailed examina- tion, it was concluded that the tooth was not restorable. With the parents’ and patient’s agreement, we decided on an autogenous transplantation of tooth #18 to the site of tooth #16 after its extraction (Fig. 2). The ortho- dontist had determined that tooth #18 was to be extracted, and it was intended that the patient’s occlusion should be balanced by the end of the orthodontic treatment. Teeth #16 and 18 were extracted in the least traumatic way possible. After minor bone remodelling of the socket us- ing low-speed burs, the third molar was transplanted to the recipient site (Fig. 3). A nylon monofilament flex- ible splint was used to keep the tooth in place (Fig. 4). Fifteen days later, the splint was removed, healthy soft tis- sue was observed, the patient was asymptomatic, and the tooth was stable in the site (Figs. 5a & b). The original plan was to proceed with the root canal therapy three weeks after the replantation, but unfortunately, the patient did not attend the appointment. According to Tsukiboshi, it is not advisable to The patient showed up to the clinic eight months later with signs and symptoms of pulp necrosis and acute periapical abscess; a periapical radiolucency was present, and the retromolar area was healed (Fig. 6). In cases like this, where the coronal structure remains intact, it is advis- able to take a conservative approach to the root canal therapy, using new technology available in endodontics to achieve good results. The endo- dontic access opening was created using high-speed burs and ultrasonic tips. The cleaning and shaping pro- tocol was performed with flexible needles and controlled memory files (Aurum Blue, Meta Biomed), espe- cially important properties for entry to the root canals through the con- servative access (Figs. 7a & b). The use of endodontic files in the stabilised martensitic stage (controlled memo- ry) will offer more resistance against cyclic fatigue.11, 13, 14 A calcium silicate- based endodontic sealer was sonically activated (CeraSeal and EQ-S, Meta Biomed) and gutta-percha was used to obturate the root canals (Figs. 8a–c). This stage of the treatment might be challenging when such a small en- dodontic access is created. The use of a calcium silicate-based endodontic sealer facilitates the obturation pro- cess, and the sonic activation helps to distribute the material all along the cleaned and shaped root canal sys- tem (Fig. 9). An adhesive coronal res- toration was placed in the same ap- Fig. 2: Periapical radiograph of the maxillary right molar. Tooth #18 was to be transplanted to the site occupied by tooth #16. Fig. 3: Tooth #18 transplanted to the site previously occupied by tooth #16. Fig.4: A nylon monofilament flexible splint was used to stabilise the transplanted tooth in the recipient site. pointment, a dual-polymerised core material (NexCore, Meta Biomed) for the pulp chamber and a compactable composite for the occlusal surface (Ezfil, Meta Biomed; Figs. 10a & b). The patient thereafter began ortho- dontic treatment, and the tooth was functional and the patient asympto- matic. The three-year follow-up ra- diograph showed healthy periapical tissue (Fig. 11). Discussion Complications reported in autog- enous transplantation cases include Figs.5a & b: Fifteen days post-op. Healthy periodontal tissue was evident around the transplanted tooth, before (a) and after (b) splint removal. Fig.6: Eight-month post-op radiograph. The retromolar area had healed, but the transplanted tooth showed signs of pulp necrosis and periapical disease. ÿPage A3