Kurt Alois Ebeleseder

Autotransplantation of a mature tooth usually leads to pulpal necrosis. Root canal treatment is recommended to prevent related inflammatory complications a few weeks after surgery. Extraoral root-end resection may facilitate reperfusion and obviate root canal treatment, but cannot be pictured with conventional dental radiography at this point in time. In the case of a lower mature transplanted molar, contrast-enhanced magnetic resonance imaging proved to be a feasible method for visualizing pulp revascularization just 4 weeks after autotransplantation. Consequently, root canal treatment was obviated. Nevertheless, the tooth had to be extracted 18 months postoperatively due to external cervical root resorption, probably caused by the extraction trauma. This allowed the histological processing and examination of the newly generated intracanal tissue. Uninflamed fibrovascular connective tissue was found, while odontoblasts or cementoblast-like cells were absent. These findings indicated that it was most likely stem cells from the bone marrow and the periodontal ligament that drove the regeneration.

Tooth germ autotransplantation of open apices of the teeth exhibits high pulpal healing rates, whereas that of mature permanent teeth normally causes irreversible pulpal necrosis. Extraoral root-end resection (EORER) during transplantation may promote pulpal revascularization (PRV) in transplanted mature teeth and reduce endodontic treatment requirement. This study compared the primary outcomes of survival rates, PRV, and root resorption and determined relevant confounders in autotransplanted mature and immature teeth. The medical charts of consecutive patients who underwent tooth autotransplantation between January 2017 and March 2021 were evaluated. Teeth with a documented follow-up of at least 1 year were included. During the study period, 59 teeth were transplanted in 44 patients. Overall, 2 teeth were excluded owing to missing data; 57 teeth were analyzed, including 25 mature teeth additionally treated with EORER. After a mean follow-up of 21.2 ± 16.1 months, no significant differences in primary outcomes were detected. Fifty-five teeth remained in situ (96.5%), and radiological signs of root resorption were detected in 9/57 teeth (15.8%). PRV was positive in 54/57 teeth (94.7%). Surgical duration and PRV failure were significantly associated with high incidences of root resorption. Mature teeth autotransplantation with EORER yielded similar results to immature teeth autotransplantation and is a feasible treatment option. Long surgery and failed revascularization increased root resorption rates. More factors should be evaluated in larger trials with longer observation periods.

In the treatment of traumatized primary teeth, the first goal is not to conserve the primary teeth but to avoid damage to the permanent ones and to build up cooperation. This leads to the question if traumatized primary teeth should be treated surgically at all. If local infection is controlled by local and, if necessary, systemic antibacterial therapy, spontaneous healing without further therapy can be found frequently. This helps not only avoiding damage to the permanent teeth and to the psychological development of the child, but also to retain more traumatized primary teeth.