Development and Evaluation of an Automated Robotic System for Full Crown Preparation

To develop a robotic system for full crown tooth preparation and to evaluate its preparation accuracy and operation time.

The robotic system comprised a robotic arm, an infrared optical tracking system, and proprietary planning/control software. The planning workflow encompassed path planning for axial and occlusal surfaces, functional cusp bevels, and acute line angles, culminating in the generation of an ideal preparation morphology. Twenty-two standardized partial dentition models of mandibular teeth 35-37 were additively manufactured and equally allocated into two experimental groups based on preparation methodology: an automated robotic system group and a step-by-step guide group. Operation time was recorded concurrently. Post-preparation scan data were imported into three-dimensional reverse engineering software to calculate the root-mean-square-error (RMSE) values for the overall surfaces, axial surfaces, occlusal surfaces, and chamfer regions to evaluate preparation accuracy.

In the posterior crown preparation model experiment, the robotic group showed significantly lower RMSE values than the guide group overall and by region: overall, 0.18±0.03 vs 0.33±0.05 mm; axial, 0.15±0.06 vs 0.27±0.08 mm; occlusal, 0.20±0.05 vs 0.38±0.07 mm; chamfer, 0.12±0.03 vs 0.30±0.07 mm. The occlusal surface yielded the lowest accuracy in both groups. The robotic system also significantly reduced preparation time (350.15±7.79 s vs. 583.93±90.48 s), confirming its efficiency advantage.

This study developed an automated robotic system for crown preparation that demonstrated superior accuracy and shorter operation time compared with the guide approach.

In this study, we developed a novel robotic system for full crown preparation that may enable precise and efficient procedures, representing a promising approach for achieving high-accuracy tooth preparation while minimizing tissue removal.