Clinical study on root resorption of autotransplanted teeth with complete root formation

IntroductionThe main reasons for the unsuccessful autotransplantation of teeth are the failure of initial healing and root resorption. The aim of this study was to elucidate the relationship between donor teeth factors and the prognosis of the transplants in which root resorption occurred.Materials and methodsThe study evaluated 110 patients with 117 transplants. The successful group included the cases which healed well, with only minor problems. The unsuccessful group included the cases with transplant-loss and progressive problems. The unsuccessful group and minor-trouble cases were judged with the type of problems; i.e. failure of initial healing, root resorption, and others. Root resorption was classified into 3 types; inflammation resorption, replacement resorption and cervical root resorption. The prognostic factors were evaluated to analyze the difference between rapidly progressing root resorption and the stable resorption.ResultsThere were 20 unsuccessful transplants. In the unsuccessful group, rapidly progressing replacement root resorption was observed in 11 transplants. In the successful group, minor problems such as stable root resorption were found in 16 transplants. At least one of the atypical root shapes (divergent, curve, and hypertrophy), probing pocket depth of more than 4 mm, and/or extrusion were significantly more frequent in the replacement root resorption cases compared to cases with no significant findings. Probing pocket depth of more than 4 mm and/or extrusion, dental caries, history of restoration, root canal treatment were significantly more frequent in rapidly progressing replacement root resorption cases compared to stable root resorption cases.ConclusionsAbnormal root shape, deep periodontal pocket, dental caries, restoration and root canal treatment of donor teeth are factors associated with progressive replacement root resorption after the autotransplantation of teeth.