A mini robot to simplify dental treatment

Researchers at the University of Basel, working with contributors from the University of Zurich, have developed a prototype miniature intraoral robot intended to prepare teeth for crowns. Called MIR, for Miniature Intraoral Robot, the device measures 43 by 26 by 28 millimeters, roughly the size of a wine cork. Its motors and control system remain outside the mouth, linked to the robot by flexible drive shafts, cables, and tubes.

The proposed workflow could shorten crown treatment. After a tooth is scanned at an initial appointment, a dentist could digitally plan the material removal, use MIR to prepare the tooth, and order the permanent crown immediately. Current treatment commonly involves decay removal, filling and tooth preparation, an impression, a temporary crown, and a later visit to place the permanent crown.

In laboratory tests on synthetic-resin tooth models and ceramic material comparable in hardness to enamel, MIR used two drilling stages. A broad drill first reduced the tooth surface from above, followed by a longer, thinner drill that shaped the sides. Despite having no sensors for directly measuring or correcting its position, the prototype achieved positional errors below 0.2 millimeters. Drilling forces stayed below five newtons, approximately the gravitational force of a half-liter bottle of water. Researchers are also examining system noise to assess practical dental use.

The robot is not yet ready for clinical practices. The team plans to add sensors and a camera to monitor position and treatment progress, including enabling recovery after a power outage using sensor data, while keeping the robot no larger. The Innosuisse-funded project involved the University of Basel, the University of Zurich's Center for Dentistry, Camlog Biotechnologies GmbH, and the University of Bern.