Accuracy of different types of surgical guides for dental implant placement

Abstract

Abstract
 BACKGROUND: Nowadays, the development of three-dimensional (3D) imaging techniques and implant planning software has contributed to a large diffusion of prosthetically guided implant placement.
 AIM: The aim of this study is to compare virtual planning accuracy of dental implant placement using various surgical templates.
 MATERIALS AND METHODS: The study involved 24 partially and fully edentulous patients. Patients were randomized according to a parallel group design into four arms: Templates for pilot osteotomy made by 3D-printing (group I), full-guide templates made by 3D-printing (group II), surgical templates for pilot osteotomy made by milling (group III) and full-guide templates made by milling (group IV). The accuracy of dental implant position was assessed by comparing the planned and actual position of the implants according to pre- and postoperative computed tomography (CT). Three mean deviation parameters (angular, at the neck position, at the apex position) were defined to evaluate the discrepancy between the planned and placed implant positions.
 RESULTS: The best results were obtained in Group III, where dental implant placement was performed using milled surgical templates for pilot osteotomy, the mean angular deviation, deviation at the neck and deviation at the apex of the implant were 4.013.21⁰, 0.380.23 mm, 0.560.51 mm respectively (p0.001 for all). In the group where milled surgical templates were used for the full guided osteotomy, the mean angular deviation was 5.665.38⁰, deviations at the implant neck and apex were 0.730.71 mm, 0.680.67 mm, respectively (p 0.001 for all), which demonstrates high accuracy of implant placement within the "safety zone".
 In groups I and II, where templates made by 3D printing were used, lower accuracy scores were obtained. In the group for pilot osteotomy, the mean angular deviation was 7.715.94⁰, the mean deviation at the neck was 1.021.07 mm, the mean deviation at the apex of the implant was 1.401.69 mm (p0.001 for all). In the group, for full guided osteotomy, the mean angular deviation, deviations at the neck and at the apex of the implant were 6.46.21⁰, 0.580.45 mm, 0.830.80 mm respectively (p0.001 for all).
 CONCLUSIONS: Dental implant placement with the use of surgical templates makes it possible to achieve a high accuracy of the implant position. Milled surgical templates are more accurate than 3D-printed templates for dental implants, which allows us to introduce surgical templates made by milling into clinical practice in order to improve the quality of dental care.