Feasibility and accuracy of semi-active robot-assisted porcelain veneer tooth preparation: An in vitro study.

OBJECTIVES

To evaluate the feasibility and accuracy of semi-active robot-assisted porcelain veneer tooth preparation.

METHODS

In total, 20 right maxillary central incisors were randomly allocated into two groups based on the preparation technique: robot and freehand (n = 10 per group). In the robot group, intraoral scanning data of a typodont with a marker were imported into robotic planning software to design a uniform 0.5-mm veneer preparation. A robotic arm equipped with a high-speed handpiece executed the preparation based on the preoperative design. In the freehand group, an experienced prosthodontist used a 0.5-mm depth-cutting diamond bur to perform the preparation manually. Post-preparation, all teeth were scanned to obtain three-dimensional data. Preparation accuracy was evaluated by calculating the root mean square (RMS) discrepancies across overall, marginal, and internal regions, with the internal region further divided into cervical, middle, and incisal thirds. Data were analyzed using multivariate analysis of variance followed by Bonferroni post hoc testing (α = 0.05).

RESULTS

Porcelain veneer preparations were completed in vitro using the semi-active robotic system. The robot-assisted group exhibited significantly higher overall RMS discrepancy (0.30 ± 0.03 mm) compared to the freehand group (0.19 ± 0.02 mm; P < 0.05). Statistically significant differences were observed across all evaluated regions (P < 0.05), including the marginal region, cervical, middle, and incisal thirds. The marginal areas exhibited the greatest RMS values in both groups, indicating lower precision in these regions.

CONCLUSIONS

Robot-assisted tooth preparation demonstrated slightly lower accuracy than that achieved by experienced operators using freehand techniques. In both groups, the marginal region exhibited the greatest deviation, indicating precision was lowest in this area.

CLINICAL SIGNIFICATIONS: The semi-active robotic system is capable of performing porcelain veneer preparations with clinically acceptable accuracy, offering a promising and effective approach for digital esthetic dentistry.