本研究的目的是比较不锈钢K-Flex锉、镍钛合金手用锉和镍钛台金机用锉在根管预备时保持原根管行径的能力。 材料和方法 选用根尖发育完成的离体牙45颗,根管的弯曲度为20°～45°,每牙利用一个牙根,多根牙截去多余的牙根。用10~#锉预通根管。在离根尖孔0.5 The purpose of this study was to compare the ability of a stainless steel K-Flex file, a nitinol file and a nitinol file to preserve the original root canal preparation during root canal preparation. MATERIALS AND METHODS A total of 45 isolated teeth were developed. The curvature of the root canal was 20 ° ~ 45 °. One tooth root was used per tooth, and the other root was cut off by multiple teeth. With 10 ~ # file pre-canal. 0.5 at the apical foramen