Accuracy evaluation of computer-guided implant surgery associated with prototyped surgical guides

Statement of problem: Correct implant placement by means of a pretreatment planning software program is still subject to deviations between the planned and achieved implant positions. Inaccuracy at this level may have drastic consequences, including neurovascular trauma. Further data are therefore needed to evaluate the accuracy of such computer-guided implant planning software programs. Purpose: The purpose of this clinical study was to evaluate the accuracy of computer-guided implant surgery associated with prototyped surgical guides. Material and methods: Cone beam computed tomography (CBCT) scans were made of the participants with a tomographic guide to merge anatomic and prosthetic data. This allowed virtual planning with a prosthetically guided approach respecting the anatomy of the participant. A prototyped surgical guide was then fabricated from the virtual plan, determining the intrasurgical position of the implants. Flapless guided implant surgery was carried out according to the manufacturer's instructions. A second CBCT was made 30 days after the surgery, to enable overlapping of the data from before and after the implant placement. The angular, coronal, central, and apical deviations of the placed implants were measured and compared with those virtually planned. The data were submitted to descriptive statistic and intraclass correlation coefficient (ICC), analysis of variance, and the Student t test (\u3b1=.05). Results: A total of 61 implants were analyzed. The mean angular deviation was 2.04 degrees. The mean coronal, central, and apical linear deviations were 0.68 mm, 0.72 mm, and 0.82 mm, respectively. No statistically significant difference was found between the virtual and the real position of the implants inserted. A tendency toward a greater absolute error was observed in the mandible than in the maxilla in terms of angular (P=.047), central (P=.043), and coronal error (P=.031). Conclusions: Flapless computer-guided implant surgery with virtual planning had some angular and linear deviations; nevertheless, this technique should be acceptably safe and accurate