To explore the effectiveness and accuracy of hollow trephines and digital surgical guides used in the preparation of autologous tooth transplantation cavities.

This study recruited 16 patients with missing molars who received autologous tooth transplantation from the patients who visited the Department of Maxillofacial Surgery, Stomatological Hospital, Guangzhou Medical University, from May 2022 to August 2022. The participants were randomly divided into a freehand group and a guided group, with eight cases in each group. The guided group took both a CBCT and an intraoral scanning. The scan results were imported into Mimics 21.0 software to analyze the recipient site and select the donor tooth region. Simulation of donor tooth implantation was performed to determine the implantation position. A digital guide template based on the hollow trephine was designed and generated. The freehand group followed the conventional autologous tooth transplantation surgical procedure. During the operation, a 3D printed donor tooth model was used for trial implantation, and the cavity was prepared manually. After surgery, patients underwent a CBCT scanning, and Geomagic Control X software was used to match and compare the preoperative designed tooth positions with the actual postoperative tooth positions.

In the 1-year follow-up, successful healing of transplanted teeth was observed in both groups. The alveolar preparation time of the guided group was (323 ± 50) s, compared with the freehand group (522 ± 91) s, and the difference between the two was statistically significant (t = 5.394, P<0.001). There was significant difference between the number of 3D donor tooth trials in the guided group (2.9 ± 0.8) and the freehand group (4.1 ± 1.2) (t = 2.357, P = 0.034). Comparative analysis of the three-dimensional position of the teeth in the guided group before and after surgery showed that the angular deviation, the 3D deviation, and the apical deviation were (9.0 ± 5.5) °, (1.0 ± 0.6) mm and (2.1 ± 1.1) mm, respectively. The positional deviation between the transplanted tooth and the preoperative designed tooth was small.

With this novel approach, the socket preparation process for autogenous tooth transplantation became reliable, accurate, controllable in depth and simplified. The harvested bone during the socket preparation can be utilized for bone grafting with great bone healing, which appeared to be a cost-saving strategy.