Massa G R, Nicholls J I, Harrington G W
J Endod. 1992 May;18(5):222-7. doi: 10.1016/S0099-2399(06)81264-1.
The torsional properties of a new type of endodontic hand instrument, the Canal Master, were compared with conventional machined K-type endodontic files. Sizes 20 through 50 were tested in clockwise (CW) and counterclockwise (CCW) directions. Canal Master instruments exhibited significantly less torque at yield and at failure in both the CW and CCW directions. Rotation at failure was significantly greater for the Canal Master instruments in both CW and CCW directions. There was no significant difference in either torque or the amount of rotation for the Canal Master instruments when comparing CW versus CCW rotation. There was no clinically visible evidence of deformation of the Canal Master instruments prior to torsional failure.
将新型牙髓治疗手动器械Canal Master的扭转特性与传统机械加工的K型牙髓锉进行了比较。测试了20至50号规格的器械，测试方向为顺时针（CW）和逆时针（CCW）。在顺时针和逆时针方向上，Canal Master器械在屈服和失效时的扭矩均显著较小。在顺时针和逆时针方向上，Canal Master器械失效时的旋转角度均显著更大。比较顺时针和逆时针旋转时，Canal Master器械的扭矩或旋转量均无显著差异。在扭转失效前，Canal Master器械没有临床上可见的变形迹象。
