Application of digital design combined with 3D-printing technologies in dental autotransplantation

To evaluate the therapeutic effect of dental autotransplantation with the application of digital design combined with 3D printing of donor tooth models and recipient alveolar fossa model preoperatively.

Twelve cases that could not be retained due to tooth fracture or extensive absorption of alveolar bone were recruited in the study. Cone-beam computed tomography (CBCT) data were imported into Mimics software for digital design, and the best-matched third molar was selected as the donor tooth. Replicas of the donor teeth and the recipient socket were printed out with three-dimensional (3D) printing technologies as a simulation model for recipient tooth socket preparation. During tooth autotransplantation, preparation of the recipient tooth socket and the donor tooth were guided by the 3D-printed replicas sequentially. Then, the donor tooth was implanted into the recipient tooth pocket. Patients were followed up at 3, 6 and 12 months after the operation, with CBCT examination to evaluate the status of bone reconstruction and periodontal ligaments at each time point.

Twelve patients were transplanted with an autogenous third molar with the apical foramen completely closed. Among them, 7 patients had alveolar fossa infection before the operation, of which 1 had extensive resorption of the alveolar bone due to the infection. All 12 patients recovered well after the operation and were followed up for at least 12 months. In total, 11 caseswere successful in tooth autotransplantation with normal mastication, and 1 case had root resorption 14 months postoperation.

Digital design combined with 3D printing technology can assistin the selection of thebest-matched donor tooth and preparation of the recipient socket before tooth transplantation proceduresand reduce the extra-alveolar exposure time of the donor tooth and number of trial placementsintothe alveolar fossa. Thus, this combined strategy can effectively improve the outcome of dental autotransplantation.