下颌第二恒磨牙C型根根管壁厚度的显微CT分析  

A micro-CT analysis of the wall thickness of C-shaped canals in permanent mandibular second molars

作　　者：顾永春 朱琦 张燕萍 周培刚 丁月峰 陈花花 周涛[2] 

机构地区：[1]吴江区第一人民医院口腔科,苏州215200 [2]西安交通大学机械学院机械制造系统工程国家重点实验室

出　　处：《实用口腔医学杂志》2014年第2期245-250,共6页Journal of Practical Stomatology

摘　　要：目的:测量下颌第二恒磨牙C型根的根管壁厚度。方法:采集到中国汉族患者拔除的C形根下颌第二恒磨牙40颗。显微CT扫描后采用Mimics 10.01软件进行三维重建;沿着牙体长轴从釉牙骨质界(CEJ)到根尖顶每隔1 mm连续虚拟横切牙根模型,观测牙根横截面上C形根管的类型(范兵分型),测量唇、舌侧以及近、远中参考位点的根管壁厚度。双因素方差分析及LSD-t检验比较不同方位的根管壁厚度。结果:40个下颌第二恒磨牙C形根被虚拟切割为370个根管横截面,其中C1根管126个(34.1%),C2根管46个(12.4%),C3根管160个(43.2%)。除了CEJ下10 mm水平,舌侧根管壁最小厚度均值总是小于颊侧,而两者又均小于近、远中参考位点处的根管壁厚度。除了CEJ下12 mm水平,4个测量位点根管壁厚度均值间的差异均有统计学意义(P<0.05)。C2和C3根管的颊侧壁最小厚度在近中区最多见,C1根管颊、舌侧以及C2、C3根管的舌侧壁最小厚度多位于中央区。结论:下颌第二恒磨牙C型根管舌侧根管壁较薄,是根管及桩道预备的危险区。Objective：To analyze the wall thickness of C-shaped canals in permanent mandibular second molars.Methods：40 ex-tracted permanent mandibular second molars with C-shaped root were collected from native Chinese and were scanned by micro-CT scan-ner.The specimens were reconstructed three-dimensionally by software Mimics 10.01.The roots were sliced from cemento-enamel junc-tion （CEJ）to apex with 1 mm intervals.The cross-sectional root canal configurations were classified into 5 types according to the Fan＆#39;s Classification.The minimum buccal wall thickness （MBWT）,minimum lingual wall thickness（MLWT）and their locations,as well as the wall thickness at the mesial and distal reference sites were detected.Two-way ANOVA and post hoc LSD-t tests were used to com-pare the mean thickness at 4 sides.Results：Among 370 cross-sections of 40 C-shaped roots,C1,C2 and C3 canals were observed on 126（34.1%）,46 （12.4%）and 160 （43.2%）sections respectively.Except at the 10 mm level,the mean MLWT was always lower than MBWT;and the MLWT and MBWT were always lower than the wall thickness at the mesial and distal reference sites.The differ-ence was statistically significant （P 〈0.05）along the root length above the 12 mm level.The MBWT of the C2 and C3 canals was more likely located at the mesial region,and the MBWT of the C1 and the MLWT of C1,C2 and C3 was more frequently located at the center region.Conclusion：The lingual wall of C-shaped canal in mandibualr second molars was the thinnest zone among four sides,and care should be taken during root canal instrumentation and post space preparation to avoid perforation.

关 键 词：下颌第二恒磨牙 C形根管 根管壁厚度 显微CT 

分 类 号：R816.98[医药卫生—放射医学]