Application of Real-time Augmented Reality-guided Osteotomy and Apex Location in Endodontic Microsurgery: A Surgical Simulation Study Based on 3D-printed Alveolar Bone Model.

[INTRODUCTION] Augmented reality (AR) is a novel visualization technique in which pregenerated virtual 3D content is superimposed on surgical sites. This study aimed to validate the viability of AR-guided endodontic microsurgery (ARG) and compare the changes in objective and subjective outcomes of surgical simulation using ARG and freehand (FH) endodontic microsurgery on customized 3D-printed models.

[METHODS] We created and printed a customized 3D alveolar bone model with artificial periapical lesions (APLs) based on cone-beam computed tomography. Eight models with 96 APLs were equally divided into ARG and FH groups. We planned surgical trajectories on rescanned printed models. Four inexperienced residents (IRs) performed ARG and FH on the models and completed pre and intraoperative confidence questionnaires for the subjective outcome. Postoperative cone-beam computed tomography scans of the models were reconstructed and analyzed, and all procedures were timed. We used pairwise Wilcoxon rank sum tests to compare objective outcomes. Kruskal-Wallis tests and post hoc pairwise Wilcoxon rank sum tests were used to compare subjective outcomes.

[RESULTS] Compared to the FH group, the ARG group significantly reduced deviation of the volume of bone removal, root-end resection, and deviation of bevel angle, with improved confidence of the IRs (P < .05); it also significantly increased surgical time and volume of unremoved APL (P < .05).

[CONCLUSIONS] We customized an APL model through 3D printing and developed and validated a low-cost AR application framework, based on free AR software, for endodontic microsurgery. ARG allowed IRs to perform more conservative and precise surgical procedures with enhanced confidence.