【摘要】 目的:评价3种常用根管预备方法预备C形根管时对根管壁薄弱区的切削程度,为临床治疗提供参考。方法:收集临床拔除的具有C形根管的下颌第二恒磨牙60颗,应用改良Bramante技术,于距根尖2、5、8mm处将牙根横断。将样本随机分为3组,使用不同预备器械和方法进行预备。比较预备前后根管横截面形态的数码图像,对3种不同方法的切削程度进行评价。评价指标包括牙本质切削面积、根管壁最小厚度出现部位及最小值变化和根管壁侧穿发生情况。数据进行方差分析。结果:C形根管壁的薄弱区多出现在舌侧,3种预备方法对C形根管壁薄弱区的切削没有显著差异。手用不锈钢器械组中发生3例侧穿。结论:在C形根管预备时应特别注意避免在颊舌侧薄弱区的过度切削,以免发生穿孔。更多还原

【Abstract】 Objective: To investigate the cutting efficiency of three instrumentation techniques in the C-shaped canals.Methods: Sixty extracted mandibular second molars,which contained C-shaped canals,were selected and cross-sectioned at 2,5,8 mm from the apex by using a muffle system as described by Bramante.The teeth were randomly divided into three groups,instrumented by three different techniques respectively.The digital images of the canal cross-sections pre-and post-instrumentation were taken to evaluate the amount of dentin removed,the position and the change of minimal canal wall.Perforation were recorded.Data were analyzed by using ANOVA.Results: The cutting efficiency on the weak wall of C-shaped canals by using three instrumentation techniques,was equivalent.The frequency of minimal walls appeared in lingual sides was much more than the others.There were three perforations in manual stainless steel K-file groups.Conclusion:The lingual wall of C-shaped canals was thinner commonly than other aspects,which should be paid more attention during canal instrumentation.更多还原