Successful healing following endodontic treatment of an autotransplanted third molar: a clinical case report

Aim.
This case report aims to demonstrate the clinical success of endodontic therapy following third molar autotransplantation.
Introduction.
Autotransplantation presents a biological and cost-effective alternative to implants and prosthetics, especially for younger patients, when replacing a lost mandibular first molar. While immature teeth can heal while maintaining pulpal vitality, endodontic treatment is essential for autotransplanted permanent teeth with a closed apex because of the lower
likelihood of revascularization. This case report describes the successful healing of an autotransplanted mature third molar five months after endodontic treatment. A 21-year-old male patient in generally good health was referred for evaluation of d36, which was deemed unrestorable due to extensive loss of coronal tooth structure and thus required extraction. The diagnoses were previously treated tooth, chronic apical periodontitis and suspected furcal perforation. The third molar, located distal to the compromised tooth, has suitable characteristics as a donor tooth and was selected for autotransplantation following the extraction of D36. To ensure minimal extraoral time the d36 was extracted before d38 explantation. The full mucoperiosteal flap was raised, the bone was removed via rotary burs and saline irrigation, and the tooth was atraumatically extracted using dental forceps with
limited pressure. Immediately after extraction, the tooth was replanted in the socket of tooth 36 and an extraoral time of a few seconds was achieved. The recipient site was anatomically wider and no preparation was needed, except for gentle curettage. The transplanted tooth was placed in the infra-occlusion position, fixed with a suture for 7 days to achieve sufficient initial stability, and a periapical radiograph was taken to evaluate its position. Four weeks later, root canal treatment was performed for d38 in one visit under rubber dam isolation and microscope (Zeiss Extaro 300) control. Three root canals were located and instrumented with Protaper Ultimate F2 (Dentply Sirona), and the working length was determined with TriAutoZx2+ (J Morita). Irrigated with 3% sodium hypochlorite solution during instrumentation.
Case presenation.
Before obturation irrigation was performed with 3% sodium hypochlorite and 17% EDTA with distilled water irrigation between solutions. Ultrasonic activation was done with Irrisafe (Acteon), final irrigant was 3% sodium hyplochorlite. Root canal obturation was performed with AH+ root canal sealer (Dentsply Sirona), and warm vertical compaction technique.
A glass ionomer liner and cavity restoration with a bonded composite restoration was placed using G-Premio Bond, GC G-aenial posterior. Follow ups were made 1 weak, 1 month, 5 months post-surgery. Radiographically, a complete periapical healing at the recipient site was observed.
Discussion.
Autotransplantation offers a biological and cost-effective alternative to implants and prosthetics, particularly in adolescent patients, without interfering with the active bone growth. Several factors were important for the success of this case - the surgical technique, ensuring minimal extraoral time, proper handling of the donor tooth, atraumatic extraction.
2,4,5 Studies have shown that reducing extraoral time significantly improves periodontal ligament viability1,2,4,5. In this case, the recipient site required no additional preparation beyond gentle curettage, which contributed to the preservation of the periodontal ligament and facilitated optimal healing. In cases where recipient site needs adjustments technology enables prior planning of a computer-aided prototyping 3-dimentional model for the
osteotomy guide. Endodontic treatment plays a critical role in the long-term prognosis of
autotransplanted teeth with a closed apex and should be carried out 2-4 weeks post- surgery, allowing to avoid external root resorption or infection3,4,5. A single-visit endodontic treatment with immediate restoration was chosen to minimize the risk of interappointment reinfection while ensuring optimal disinfection and sealing of the root canal system. Although long-term follow-up is preferred, the current status of the tooth is asymptomatic, in functional occlusion, with the healing of the surrounding bone suggest a positive outcome.
Clinical relevance.
This case underscores the importance of proper case selection, precise surgical technique, and well-timed endodontic intervention in achieving successful outcomes in autotransplantation of teeth with mature apices. While long-term monitoring remains essential, this approach provides a promising alternative for managing non-restorable molars, particularly in young patients where maintaining alveolar bone is crucial for future prosthetic or orthodontic considerations.