VirtuEleDent: A Compact XR Tooth-Cutting Training System Using a Physical EMR-based Dental Handpiece and Teeth Model

Dental cutting is a crucial skill for dental students. However, current VR dental cutting training systems rely on bulky and costly haptic devices, which reduce opportunities for individual practice. Moreover, the limitations imposed by the maximum reaction force of an active haptic device would impact the range of tooth hardness that can be reproduced. We propose a compact XR tooth-cutting training system, VirtuEleDent, that employs a passive haptic approach using a 3D-printed physical teeth model and a three-dimensionally tracked handpiece. Their spatial relationship is accurately rendered in the virtual environment of a mobile head-mounted display (HMD), providing users with realistic haptic sensations during virtual tooth-cutting exercises. Our tracking platform is operated using electromagnetic resonance (EMR) stylus technology and consists of a digitizer (i.e., tracking board) and a handpiece device. A customized EMR stylus unit (i.e., resonance coil) and an inertial measurement unit (IMU) sensor are installed inside the handpiece, allowing for precise measurement of its tip’s 3D position and orientation. This setup enables the learner to physically manipulate dexterous handpieces on the teeth model while experiencing virtual tooth-cutting in the HMD. First, we detail the design and implementation of our initial prototype system, including the tracking platform. We then describe an expert user study conducted with our prototype, where licensed dentists compare VirtuEleDent to a baseline with a conventional haptic device. Finally, the educator’s feedback demonstrates its potential and informs our further improvements and the directions of future development.