Dental Haptic Simulator to Train Hand Skill of Student

Objectives: In dentistry the exquisite hand skill is required for daily treatments, and acquisition of the skill is essential for dental students. However, conventional dental practice using phantom mannequin has the limitation for the case setting and the frequency of practice. In the present study, by using haptic device which feels the virtual sense of touch, we developed a prototype educational system to train tooth preparation, and examined the operationality and the limit of the available teeth data memory size. Methods: Original software which enables haptic tooth preparation was composed with Voigt model with parallel linked spring and dash pot. Digital models of turbine hand piece with exchangeable bars and upper and lower dentitions were fed into computer. Memory size of dentition was prepared from 0.43MB to 29.8MB. Hardware used are a commercially available haptic device (PHANToM Omni, SensAble Technologies, USA) and a computer with Dual Core Intel Xeon 5160 CPU (wx6400, Hewlett-Packard Co., Ltd, Japan). Results: Turbine handpiece could be handled by operating the manipulator of haptic device, and touch to the teeth could be perceived. The appropriate force to feel the hardness of teeth could be obtained by the spring constant of Voigt model from 0.5 to 2.0, and with larger value excessive force was perceived. By pushing the button of haptic device, we could prepare the teeth with the sense of cutting. The dash pot constant from 0.08 to 0.03 was appropriate, and with larger value excessive repulsion was sensed. In the dentition model with larger memory size than 7.6MB, delay of operation of handpiece was observed, while the roughness of the tooth shape was observed less than 0.9MB.Conclusion: Original educational prototype system to train tooth preparation with virtual haptic force was developed. This will be useful for on demand training of hand skill of dental student.