三种器械预备弯曲根管成形效果的比较

目的：评价K锉、Safesiders锉和HERO Shaper锉预备离体牙弯曲根管的成形效果。方法60颗根管弯曲的离体下颌前磨牙随机分为3组，分别用K锉、Safesiders锉和HERO Shaper锉进行根管预备，根管预备前后分别往根管内注入复方泛影葡胺并拍摄X线片，分析根管预备后根管弯曲内外侧壁牙本质去除量、中心定位能力及根管直化角度。结果在根管弯曲内外侧壁所有观测点，Safesiders锉组和HERO Shaper锉组牙本质去除量均少于K锉组（P均＞0.05）。 Safesiders锉组牙本质去除量多于HERO Shaper锉组，但仅在根管弯曲内侧壁3和4 mm观测点处差异有统计学意义（3 mm：t＝3.72，P＜0.05；4 mm：t＝7.62，P＜0.05）。在距根尖孔5 mm以下观测点，Safesiders锉组和HERO Shaper锉组中心定位能力优于K锉组（1 mm：F＝7.45，P＜0.05；2 mm：F＝10.20，P＜0.05；3 mm：F＝7.75，P＜0.05；4 mm：F＝23.45，P＜0.05；5 mm：F＝10.91，P＜0.05）；而在所有观测点上，Safesiders锉组与HERO Shaper锉组差异均无统计学意义（P均＞0.05）。 Safesiders锉组和HERO Shaper锉组根管直化角度均小于K锉组（F＝58.95，P＜0.05），但Safesiders锉组与HERO Shaper锉组间差异无统计学意义（P＞0.05）。结论 K锉、Safesiders锉和HERO Shaper锉预备离体牙弯曲根管均有不同程度的根管偏移，其中Safesiders锉和HERO Shaper锉根管偏移较少，具有较好的根管成形效果。

Shaping efficacy of three instruments in curved root canal preparation

Objective To evaluate the shaping efficacy of K files , Safesiders files and HERO Shaper files in curved root canal preparation of human teeth in vitro. Methods Sixty mandibular premolars with curved root canal were divided into three groups randomly, and prepared by K files, Safesiders files and HERO Shaper files respectively. Compound meglumine diatrizoate was injected into root canals and X-ray graphs of teeth were taken before and after instrumentation . The amount of dentin removed from inner and outer walls , centering ability and degree of straightening of root canal after preparation were analyzed. Results Safesiders files and HERO Shaper files removed less dentin from inner and outer walls than K files at all measuring points （P〈0.05）. Safesiders files group displayed more dentin removed than HERO Shaper files group, however, the differences were not statistically significant except for the 3 mm and 4 mm measuring points in inner walls （P〈0.05）. Safesiders files group and HERO Shaper files group showed better centering ability than K files group at measuring points below 5 mm （P 〈 0.05）, and differences between Safesiders files group and HERO Shaper files group was not statistically significant （P 〉 0.05）. The use of K files resulted in more straightening of root canal after instrumentation compared to other instruments （P 〈 0.05）, and the differences between Safesiders files group and HERO Shaper files group was not significant （P 〉 0.05）. Conclusions K files, Safesiders files and HERO Shaper files caused transportation when preparing curved root canals . Safesiders files and HERO Shaper files showed less transportation and better shaping efficacy .