Efficacy of root canal treatment for autotransplanted third molars: a 6-Year cohort study of 167 teeth in southern China.

BACKGROUND

Autogenous tooth transplantation offers significant advantages and promising success rates for replacing non-retainable teeth. This study aimed to investigate the prognostic factors, especially the impact of root canal treatment (RCT), of autotransplanted teeth in an up-to-6-year follow-up cohort of 167 teeth in Southern China.

METHODS

We enrolled adult patients from the Southern Medical University-Shenzhen Stomatology Hospital between 2017 and 2023. Patients underwent autogenous tooth transplantation to replace non-retainable molars with upper or lower third molars with Moorrees tooth development stage ≥5. All surgical procedures were performed by an experienced surgeon. The included patients were followed up for 6~72 (median 28.5) months. Success, failure, and survival rate and prognostic factors were evaluated using univariable Kaplan-Meier, multivariable generalized linear regression, and multivariable COX regression analyses.

RESULTS

The overall success rate is 97.6% with four unsuccessful cases. Herein, two of them were removed, leading to an overall survival rate of 98.8%. A total of 159 cases (95%) received RCT in 3 months. Univariable log-rank analysis showed that RCT (RR 0.109, 95%CI 0.010 to 1.202, = 0.028) and site relationship between donor and receipt sites (RR 3.359, 95% CI [1.210-9.329], = 0.020) were two significant prognostic factors of autotransplanted teeth. Multivariable generalized linear regression revealed that RCT is the only significant factor protecting the success rate of autotransplanted teeth (HR 0.003, 95% CI [0.000-0.249], = 0.010). However, in the Cox regression model, the effects of RCT (HR 0.009, 95% CI [0.000-2.514], = 0.101) did not reach statistical significance. Other factors did not demonstrate a significant impact in this cohort. These results supported that autogenous tooth transplantation is a viable alternative to conventional implant treatment with strict indications. Our findings underscore the importance of RCT in transplanted teeth with closed or semi-closed apices. Multi-center observational studies with larger sample size and extended follow-up duration may be needed to validate the conclusion.