摘要
目的:确定下颌前磨牙牙体长轴和釉牙骨质界,建立三维有限元分析模型,研究牙槽骨吸收程度对下颌前磨牙牙周膜承受应力的影响。方法:选择离体下颌前磨牙,通过micro-CT扫描重建牙齿三维图像、通过锥形拟合法确定牙体长轴、手工划定釉牙骨质界,将牙根十等分、划分单元格、设定模型力学性质、设定加载,建立下颌前磨牙的三维有限元模型。加载力值100N;加载方向为与牙体长轴平行、与牙体长轴成45°、与牙体长轴垂直;加载位置位于牙体长轴与(牙合)面相交的点。分析不同牙槽骨吸收程度、不同加载方向下牙周膜所受的最大VonMises应力值。结果:结合牙体长轴、釉牙骨质界的概念,建立了三维有限元分析模型。随着牙槽骨吸收程度的增加,下颌前磨牙牙周膜的Von Mises应力最大值显著增高。在与牙体长轴平行的加载力作用下,牙槽骨吸收达到50%时下颌前磨牙牙周膜承受的最大应力为牙槽骨无吸收时的2倍;在与牙体长轴垂直或与牙体长轴成45°的加载力作用下,下颌前磨牙牙槽骨吸收30%时牙周膜最大应力值达到牙槽骨无吸收时的2倍。结论:在建立三维有限元分析模型时结合牙体长轴、釉牙骨质界的概念,有利于规范和统一加载方向、模拟不同牙槽骨吸收量。对于下颌前磨牙牙周膜应力分析结果表明,当牙槽骨吸收至30%时将会对牙周组织造成损伤。
Objective：To establish three dimensional finite element analysis models based on tooth long axis, and to investigate the effects of alveolar bone loss on stress distribution of periodontal ligament of mandibular premolar.Methods：A sound extracted mandibular premolar was selected. Finite-analysis modeling procedures included micro-CT scanning, the digital tooth modeling, determining the long axis and the cemento-enamel junction, dividing the root into ten equal sections, and establishing the stress analysis model. The loading force was 100N, and the loading directions were either parallel, perpendicular, or 45 degrees to the tooth long axis. The values of maximum Von Mises stress were calculated.Results：Three dimensional finite element analysis models were established based on tooth long axis and the cemento-enamel junction. The values of maximum Von Mises stress increased along with the ratio of alveolar bone loss. When the forces were applied parallel to the long axis of the tooth,the maximum Von Mises stress of periodontal ligament in 50% alveolar bone loss is two times higher than normal teeth without bone loss. When the forces were applied perpendicular, or 45 degrees to the long axis of the tooth, the maximum Von Mises stress of periodontal ligament in 30% alveolar bone loss was two times higher than normal teeth without bone loss.Conclusion：For mandibular premolars, the alveolar bone loss up to 30% will cause damage to the periodontal tissues.
出处
《中华老年口腔医学杂志》
2015年第2期75-79,共5页
Chinese Journal of Geriatric Dentistry
基金
国家自然科学基金(项目编号:3081307)
北京市科技计划项目(项目编号:2010B078
Z141100002114031)
关键词
下颌前磨牙
牙体长轴
牙周膜
有限元应力分析
牙槽骨吸收
mandibular premolars
tooth long axis
periodontal ligament
three dimensional finite element analysis
alveolar bone loss
