Accuracy of virtually planned and CAD/CAM-guided implant surgery on plastic models.

STATEMENT OF PROBLEM: Studies of guided implant surgery have identified various methods that could influence accuracy. The present investigation was designed to limit the factors contributing to accuracy and to compare the results for 5 different surgeons. PURPOSE: The purpose of this study was to evaluate any deviation between virtually planned and actually placed implants by 5 surgeons performing computer-aided design/computer-aided manufacturing (CAD/CAM)-guided implant surgery on duplicate plastic models. MATERIAL AND METHODS: Five surgeons participated in the study, and each received 5 plastic maxillary jaw models. Thus, 25 models were used for implant placement with CAD/CAM-fabricated surgical templates. Each model contained 6 implants; therefore, a total of 150 implants were placed. The virtually planned and actually placed implant positions were compared for the apex, hexagon, depth, and angle with 2 computed tomography scans that were matched with voxel-based registration software. In addition, any differences in the 4 parameters among the surgeons were statistically tested. The data were analyzed with the t test, ANOVA, and Scheffe test (alpha=.05). RESULTS: A statistically significant difference between the virtually planned and actually placed implant positions was observed for 3 of the 4 outcome variables (the apex, hexagon, and depth; P<.05). A statistically significant difference was also noted among all surgeons regarding the positions of the apex, depth, and angle. CONCLUSIONS: The results of this study provide a better understanding of the differences in accuracy between surgeons when using a CAD/CAM surgical technique. There was a significant difference between the virtually planned and actually placed implant positions and between the surgeons for some of the variable parameters analyzed. The null hypothesis was thus rejected.