摘要
目的分析不同的粘固剂厚度对上颌中切牙桩核冠修复后剩余牙本质和粘固剂应力状况的影响。方法采用三维有限元分析方法,建立不同粘固剂厚度的上颌中切牙桩核冠修复的三维有限元模型,模拟前伸和正中加载,选取指标为Von Mises应力、最大主应力和剪切力,分析粘固剂层厚度变化对牙本质和粘固剂的应力分布以及应力峰值的影响。结果随着粘固剂层的增厚,各模型牙本质应力分布基本相似,前伸加载时3个模型牙本质内Von Mises应力和最大主应力集中区均在根尖,正中加载时两种应力的集中区同时出现在舌侧颈缘及根颈1/3;牙本质内Von Mises应力和最大主应力的峰值略有减小,而粘固剂层的Von Mises应力峰值、最大主应力峰值以及剪切应力峰值均明显减小,其中在前伸加载、粘固剂厚度为100μm时粘固剂层XY和YZ方向剪切应力峰值下降最为明显,分别达到了63.22%和51.46%。结论粘固剂的厚度变化对牙本质的应力影响较小,而对粘固剂本身影响较大,适当增加粘固剂的厚度可以降低粘固剂的应力峰值。
Objective To investigate the effect of different thickness of cement on residual dentine and stress statement in post and core restored maxillary central incisor. Methods The three dimensional finite element models of post and core restored maxillary central incisor with different thickness of cement were estab- lished by computer, with simulation of the protruding and oblique loads. The stress peak and distribution of dentine and cement of Von Mises, the maximum stress and shear stress were analyzed to investigate the effect of different thickness of cement in each model respectively. Results The stress distribution inside the dentine from different models was similar with the increase of thickness of cement. Under protruding load, Von Mises and the maximum stress on dentine in three models showed significant stress concentration at root apex, but for oblique load, the stresses showed significant stress concentration at the lingual cervical margin and at the cervi- cal one third of the tooth. The peaks of Von Mises, and the maximum stress inside the dentine were indistinc- tively reduced, but the peaks of them and shear stress in the cement were reduced obviously. When the thick- ness of cement was 100 μm under protruding load, peak value of shear stress in XY and YZ direction on the cement was reduced most significantly, by 63.22% and 51.46% respectively less than when the thickness was 30 μm. Conclusion The thickness of cement has few effects on stress of dentine, but significant on cement itself, which suggests it can reduce the stress peak in cement when proper increasing the thickness.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2013年第14期1485-1488,共4页
Journal of Third Military Medical University
基金
河南省医学科技攻关计划(201203086)~~
关键词
桩核
粘固剂
上颌中切牙
三维有限元
post and core
cement
maxillary central incisor
three dimension finite element
