Semi-automated robot for tooth restorative treatment: a pilot feasibility study

Background Current workflows for crown restorations remain sequential: the tooth is prepared first, then scanned, designed, milled, and seated. If a robotic system can execute a tooth preparation to a preoperatively defined geometry with sufficient accuracy, the matching crown can instead be manufactured from the preoperative plan — before or in parallel with patient preparation — and seated immediately after. This study reports the initial clinical evaluation of a semi-automated robotic preparation (SARP) system enabling this workflow. Methods In this single-arm, early feasibility study, the clinical team performed single-unit posterior crown procedures in six participants. Following a preoperative digital scan and treatment plan, a monolithic zirconia crown was designed and fabricated in advance. At the treatment visit, the SARP system executed the programmed tooth preparation under continuous clinician supervision via a foot-activated safety switch, and the clinician seated and cemented the pre-manufactured crown. Results Here we show that the planned robotic preparation was completed in all participants, with no adverse events recorded. All participants report no pain or discomfort during the procedure, immediately afterward, or at one-week follow-up. Preparations show a mean root-mean-square (RMS) deviation of 39 µm from the planned shape, with a mean per-tooth standard deviation of 38 µm and 98% of the prepared surface within ±100 µm of plan. Five of six premanufactured crowns (83%) demonstrate a good or perfect fit and are permanently cemented; the remaining crown was used as a provisional restoration. Conclusions The findings suggest that semi-automated tooth preparation is a feasible and accurate approach to restorative dentistry. Preparation accuracy decouples crown fabrication from the preparation step, allowing the crown to be produced in advance or in parallel. Ongoing larger trials will evaluate the long-term clinical and economic impact.