不同材料不同形态桩核修复上颌中切牙牙本质应力有限元研究.doc

不同材料不同形态桩核修复上颌中切牙牙本质应力有限元研究[摘要] 目的 应用三维有限元法研究上颌中切牙不同形态不同材料桩核修复后牙本质内的应力分布。方法 通过螺旋CT扫描、Unigraphics（UG）软件建立锥形桩、柱形桩修复的上颌中切牙三维有限元模型，模拟聚乙烯纤维树脂、碳纤维及氧化锆3种不同弹性模量桩核材料，在上颌中切牙舌侧切1/3与中1/3交界处，与牙体长轴成45°切龈向加载，载荷量为100 N，加载方式为静态加载，分析牙本质内的Von Mises应力。结果 氧化锆作为桩核材料时，柱形桩牙本质界面应力值显著高于锥形桩（P＜0.05）；当桩核材料为碳纤维和聚乙烯时，锥形桩与柱形桩之间牙本质 界面应力值差异无统计学意义（P＞0.05）。随着桩核材料弹性模量的增大，牙本质应力也增大。结论 当选择高弹 性模量桩核材料时锥形桩优于柱形桩。尽可能选择低弹性模量桩核材料有利于应力分布，防止根折。临床在桩冠根管制备时尽可能地保留根颈1/ 3处根内牙本质，尤其是唇侧牙本质厚度。 [关键词] 桩核； 应力； 三维有限元分析 [中图分类号] R 318.01 [文献标志码] A [doi] 10.3969/j.issn.1000-1182.2012.02.005 Three dimensional finite element analysis on stress distribution in dentin of the maxillary central incisor restored with different shapes and materials of post Zhang Xuying1, Sun Jing2, Lu Jun3. （1. Dept. of Prostho-dontics, School of Stomatology, Tongji University, Shanghai 200072, China; 2. Dept. of Dental Implantology, School of Stomatology, Tongji University, Shanghai 200072, China; 3. Dept. of Stomatology, PLA No. 411 Hospital, Shanghai 200081, China） [Abstract] Objective To investigate the stress distribution in dentin of the maxillary central incisor restored with post-core which is related to different shapes and materials. Methods CT scan, digital-image processing and Uni-graphics（UG） software were applied to construct the three-dimensional finite element models of maxillary central incisor restored with cone or column post-core. Based on this model, stress distribution of Von Mises in dentin with three different materials（polyethylene fiber resin, carbon fiber and zirconia） were analyzed respectively. Static loading（100 N） was used on the lingual boundary line between upper-one-third and middle-one-third of maxillary central incisor, the direction of the loading was 45° to the tooth long axis. Results In posts made of zirconia and restored with column post, the stress distribution in dentin was higher than with cone post（P＜0.05）. In posts made of polyethylene fiber resin or carbon fiber, there was no significant differenc