BACKGROUND: Computer-assisted implant surgery usually requires a radiographic scan template as the basis for prosthetic-driven implant planning and surgical guide fabrication. PURPOSE: The study aims to evaluate the accuracy of image-fusion stereolithographic guides in which a computed tomography (CT) scan is mapped with three-dimensional optical scans of cast and diagnostic wax-up. MATERIALS AND METHODS: Three-dimensional error at the base and tip of the implants, angular deviation of the implant-axis, and the inserting-depth error of 120 implants with a length of 10 mm and a caliber of 4.1 mm in 15 polymer-models were examined. A control CT was performed and fused with the planning data for accuracy evaluation. RESULTS: The mean three-dimensional error was 0.21 ± 0.10 mm (0.00-0.48 mm) at the implant base, 0.32 ± 0.17 mm (0.03-0.75 mm) at the implant tip, and the mean angular error was 0.85 ± 0.59° (0.00-2.50°). The mean depth error was 0.07 ± 0.07 mm (0.00-0.32 mm). CONCLUSIONS: Within the limitations of an in vitro study, the novel technique showed excellent accuracy. Errors from fabrication and scanning of a radiographic scan template can be avoided, and the workflow and costs of computer-assisted implant surgery may be reduced.
BACKGROUND: Computer-assisted implant surgery usually requires a radiographic scan template as the basis for prosthetic-driven implant planning and surgical guide fabrication. PURPOSE: The study aims to evaluate the accuracy of image-fusion stereolithographic guides in which a computed tomography (CT) scan is mapped with three-dimensional optical scans of cast and diagnostic wax-up. MATERIALS AND METHODS: Three-dimensional error at the base and tip of the implants, angular deviation of the implant-axis, and the inserting-depth error of 120 implants with a length of 10 mm and a caliber of 4.1 mm in 15 polymer-models were examined. A control CT was performed and fused with the planning data for accuracy evaluation. RESULTS: The mean three-dimensional error was 0.21 ± 0.10 mm (0.00-0.48 mm) at the implant base, 0.32 ± 0.17 mm (0.03-0.75 mm) at the implant tip, and the mean angular error was 0.85 ± 0.59° (0.00-2.50°). The mean depth error was 0.07 ± 0.07 mm (0.00-0.32 mm). CONCLUSIONS: Within the limitations of an in vitro study, the novel technique showed excellent accuracy. Errors from fabrication and scanning of a radiographic scan template can be avoided, and the workflow and costs of computer-assisted implant surgery may be reduced.