三种方法预备下颌第二磨牙C形根管成形效果的比较  

Comparative study of shaping efficiency in C-shaped canals of mandibular second molars

作　　者：周欣[1] 马琦[1] 尹兴喆[1] 张成飞[1] 

机构地区：[1]北京大学口腔医学院·口腔医院特诊科,100081

出　　处：《中华口腔医学杂志》2008年第3期151-153,共3页Chinese Journal of Stomatology

摘　　要：目的评价3种常用根管预备方法对C形根管的成形效果，为临床治疗提供参考。方法对临床拔除的具有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2mm、5mm和8rain处将牙根横断。选择手用不锈钢K锉逐步后退技术（Step-Back组）、逐步深入技术（Step—Down组）和机用旋转镍钛锉ProTaper^TM系列冠向下预备技术（Crown-Down组）预备不同类型的C形根管，比较预备前后根管横截面形态的数码图像，对3种不同方法的成形效果进行评价。结果3种方法预备离体下颌第二磨牙C形根管后均有遗漏。不锈钢K锉逐步后退技术和不锈钢K锉逐步深入技术分别在根冠部[遗漏面积百分比分别为（0．177±0．071）％、（0．068±0．074）％]和根尖部[遗漏面积百分比分别为（0．236±0．167）％、（0．295±0．171）％]遗漏较少（P〈0．05）。CⅠ、CⅡ型遗漏出现在近远中多于颊舌侧，将其分为独立的2～3个根管预备可减少遗漏。不同方法预备根尖区的遗漏均显著高于根管中上部（P〈0．05）。结论早期开敞根管上段，将C形根管分为2～3个独立的根管进行预备，可以增进根管预备的成形效果。Objective To investigate the shaping efficiency of three instrumentation techniques in the C-shaped canals. Methods Sixty extracted mandibular second molars with 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 containing C-shaped canals were randomly divided into three groups, respectively instrumented using stainless steel K-files in step-back and step-down techniques, and ProTaper^TM series in crown-down technique. The digital images of canal cross-sections pre- and post-instrumentation were photographed to evaluate the proportion and position of uninstrumented area. Working length loss and perforation were recorded. Data were analyzed using ANOVA. Results Step-down technique gained smaller uninstrumented area in the coronal third of the canals, while step-beck technique gained the same results in the apical third （ P 〈 0. 05）. Uninstrumented proportion in apical part was significantly higher than in the middle and the coronal （P 〈 0. 05 ）. Instrumenting type Ⅰ canal as 2 or 3 separated canals was likely to reduce the miss. There were three perforations in manual stainless steel K-file groups. Conclusions Early opening the coronal part of C-shaped canal, shaping C-shaped canal as two or three separated canals and instrumenting the apical part with step-back technique, seemed to be the effective methods to avoid miss.

关 键 词：牙髓腔 根管制备 牙科高速技术 

分 类 号：R686[医药卫生—骨科学]