Accuracy of Computer-Guided Implant Surgery by a CAD/CAM and Laser Scanning Technique

Objectives: To explore the method of manufacturing an implant surgery template with a computer-aided design/computer-aided manufacturing (CAD/CAM) technique and evaluate its precision in clinical cases. Methods: Patients referred to the 2nd Dental Center of Peking University who were partially edentulous, were enrolled and scanned with cone beam computed tomography (CBCT). Diagnostic casts were laser scanned to record the configuration of the patients' dentition and mucosae. CBCT and laser scanning data were subsequently loaded into Simplant software. Implant positions were planned in the software with a computer-aided design technique, and surgical templates were fabricated with a rapid prototyping technique. These templates were used to guide implant placement surgery. Results: The mean value of linear deviation was 1.00 mm (range 0 to 2.16 mm) for implant shoulder and 1.26 mm (range 0.51 to 2.86 mm) for the implant apex. The mean angular deviation was 4.74 degress (0.37 to 10.28 degrees). Deviations were higher in the posterior region than anterior. The tooth-supported template provided higher precision than did the tooth/ mucosa-supported template, but no statistically significant difference was found. Conclusion: Computer-guided implant surgery with the CAD/CAM technique provides dentists with a good platform for preoperative planning, precise implant insertion, and ideal rehabilitation. The protocol of this three-dimensional laser scanning technique can provide precision comparable to that of double-scanning. Keywords: tooth implant, computer-aided design, rapid prototyping, implant surgical template, laser scanning