Accuracy of dental implant placement using chairside computer-aided surgery/computer-aided manufacturing-milled guides compared to three-dimensional printed guides

Abstract

Background: In-office devices are increasingly used in dental practices to mill “chairside” restorations for increased turnover. New functions permit milling implant surgical guides, thus cutting the time and cost of treatment. This study compares the accuracy of chairside-milled surgical guides (CMG) with that of high-accuracy laboratory-based three-dimensional (3D)-printed guides (PGs). Methods: In this in vitro study, 10 bone-level cylindrical implants (4 mm × 13 mm) were placed using both guide types (five for each) in 10 similar prefabricated plastic models with the aid of a specially designed machine. The positions of the placed implant were compared to the planned positions by superimposing postsurgical cone-beam computed tomography scans over the preoperative scans and by measuring the horizontal, vertical, and angular deviations within each study group. Results: The horizontal deviation at the implant neck was 0.37 mm ± 0.16 for CMG and 0.84 mm ± 0.35 for PG (P < 0.05). The horizontal deviation at the apex was greater; 0.76 mm ± 0.49 for CMG and 1.70 mm ± 0.46 for PG (P < 0.05). The vertical deviations in both groups were smaller than the horizontal values and almost identical at the neck and apex within each group (0.26 mm ± 0.13) and (0.37 mm ± 0.25) for CMG and PG, respectively (P > 0.05). The angular deviation of the implant's long axis for PG (4.10° ± 1.96°) was twice as large as CMG (2.0° ± 1.37°), but the difference was not statistically significant (P = 0.08). Conclusion: Chairside milled guides demonstrated higher accuracy and predictability compared to laboratory-based 3D-PGs.