Development of a multi-layered virtual tooth model for the haptic dental training system.

A virtual reality (VR) haptic dental training system could be a promising tool for future dental education. One major challenge is to develop a virtual tooth model which similarly reflected a real tooth having multiple layers with different mechanical hardness in each layer. The multi-layered virtual tooth model was successfully constructed in our virtual system. The constructed model allows us to feel tooth cutting which is similar to that with a real tooth. Through a cutting experiment by using the real tooth, a spring coefficient and a damping coefficient of a dental hard tissue were determined 0.8 N/mm and 1.79 Nsec/mm respectively. The feedback force smoothly altered when crossing the border of regions having different mechanical hardnesses. The constructed model introduced in this study could be a promising tool for acquiring dental hand skills in a virtual learning system.