電気的根管長測定器を内蔵したハンドピースに関する研究

2. ファイルに加わる応力

抄録

Abstract : We have developed and already reported on a new cordless engine driven root canal preparation system which electronically monitors the location of the file tip during instrumentation procedures.

 The load, torque, rotation speed, and current flowing through the motor were measured when this system was used with nickel-titanium files for the preparation of human extracted tooth canals.

 The maximum load applied to the tooth was approximately 800 gram. The maximum torque observed in this system was approximately 450 g-cm. There was a linear relation between the magnitude of the torque and the current flowing through the motor. It was assumed that the Auto-torque-reverse mechanism should start at 40-80 g-cm when the ProFile or McXIM file was used. This torque range corresponded to the motor current of 100-200 mA. The rotation speed of the motor decreased as the load or torque increased, although this change was in a small range (240-280 rpm).

 This Auto-torque-reverse mechanism promises to prevent file breakage.