Abstract: Objective　 The purpose of this study was to present and assess the accuracy of guided endodontic microsurgery with 3D-printed template. a novel approach of periapical microsurgery, based on the application of templates produced using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Methods　20 patients suffered from the failure of root canal therapy in our hospital were chosen. Periapical microsurgery were performed on all 20 patients, randomly assigned into two groups, . Guiding template fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) technology was used in the study group after virtual surgical planning and simulation. While traditional method was applied in the control group.the study group with virtual surgical planning and simulation, transfer of the virtual surgical planning to operation room assisted with guiding template fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) technology, the control group with traditional traditional method. The postoperative 3-dimensional reconstructed computed tomography image and the presurgical plan were compared to evaluate the accuracy. Results　The accuracy of periapical microsurgery based on 3d-printed based on templates in the study group were better than those in the control group. There was significant difference between the two groups (P<0.05). Conclusions　The 3D-printed template could effectively guid periapical microsurgery, providing positional control with considerable surgical accuracy, which is worthy of clinical application.

Key words: 3D printing, Surgical template, Chronic apical periodontitis, Endodontic microsurgery