机械预备对根管弯曲度改变的体外研究

目的 比较手工不锈钢K锉、步退法和机用旋转ProTaper镍钛锉、改良冠向下法对弯曲根管弯曲度的改变和根管成形的效果.方法 60个离体后牙的弯曲根管分成A、B两组,分别使用手工不锈钢K锉、步退法和机用旋转ProTaper镍钛锉、改良冠向下法进行机械预备,对根管预备前后的样本拍摄X线片,测量机械预备前后根管的弯曲度,分析预备前后根管弯曲度的改变.结果 两种预备法机械预备前后根管弯曲角度的差值有显著性差异（P=0.012）.结论 机用旋转ProTaper镍钛锉预备具有良好的根管成形效果.

A invitro study of changes in root canal curvature of mechanical preparation

Objective To compare the changes in canal curvature and shaping ability after canal preparation with the stainless steel K-files by hand, step-back technique and ProTaper NiTi rotary files, crown-down technique treatment. Methods Sixty curved root canals in vitro were randomly divided into A, B groups, prepared with hand stainless steel K-files, step-back technique and specimens in group B were prepared with ProTaper NiTi rotary files, crown-down technique respectively. Shot sample X-ray pre-instrumentation and post-instrumentation. The difference between the pre-instrumentation and post-instrumentation angles was analyzed. Results The decrease tendency of the root canal curvature in hand stainless steel K-files group was more obvious than in ProTaper NiTi rotary files group （P=0.012）. Conclusion The ProTaper NiTi rotary files preserved the original canal to a greater degree than the stainless steel K-files.