Mini Robot Dentist Fits Inside Your Mouth To Precision Drill For Crowns

A research team at the University of Basel has developed a prototype robot that can automate dental crown preparations directly inside a patient's mouth. Known as the Miniature Intraoral Robot (MIR), this device could eventually cut down the need for multiple dental visits by streamlining how teeth are shaped for restorations.

Unlike a typical medical robot that relies on arms to work on a patient (that also needs to track and compensate for patient head tilting, swallowing, and shifting), the MIR is a much simpler machine the size of a wine cork—measuring just 43mm long, 26.4mm wide, and 27.6mm tall—and it mounts directly onto a custom, 3D-printed splint attached to the patient's teeth. 

To achieve this small footprint, engineers separated the robot's mechanical components from its cutting tool. While the heavy motors and control hardware sit outside the mouth near the dental chair, flexible shafts, cables, and tubes transfer power directly to the drill. During a procedure, the robot operates in two distinct phases: first utilizing a wider cutting bur to strip material from the top surface of the tooth, then switching to a longer, narrower tool to shape the sides into a conical profile required for a crown.

In initial laboratory trials on synthetic resins and hybrid ceramics that mimic human enamel, the prototype achieved remarkable accuracy. Even though the current iteration lacks onboard sensors to adjust its path in real time, i.e. relying instead on motor encoders located about 30 cm away, the average positioning error remained below 0.18mm. The largest observed error reached 0.47mm, while the consistency of its path deviated by 0.087mm.