Impact of vibration in curving work by electrical dental motor

Objectives: The aim of this study is to know the transmission of vibration of the dental motor in technical procedures and to protect dental technicians form vibration disease in hand and arm area. Methods: Tow small 2 axes accelerometers are put on a motor and a finger. Vibration was measured when the subjects were curving dental stones and plastics form two points: the motor and a finger. As a control vibration made by hand writing was measured. Results: In curving stones(0.089G) greater acceleration was observed than in plastics (0.087G) or in hand writing(0.068G). There were no statistical differences between them. About absorption of the vibration, the stone showed greater value. Conclusion: In low frequency area ( < 8 Hz ), vibration was well transmitted to the finger. Impact of the curving work was estimated around 20 times greater than the writing work, calculating by mass ratio. This study was supported by JSPS KAKENHI (21592444)