| 摘要 |
<p>An endodontic device is described including: a file adapted to remove by abrasion the dental material by a rotary working motion; an AC or DC motor, adapted to drive the file in the working motion according to two opposite verses of rotation; a pair of optical or magnetic encoders controlling a position mounted in quadrature of the driving shaft, to evaluate the angular position of the file and consequently control the motor.</p> |
