牙槽骨高度对上颌前磨牙桩核冠修复后应力分布的影响  

Influence of the alveolar bone height on stress distribution of post and core restored maxillary premolar

作　　者：刘诗铭[1] 刘玉华[1] 徐军[1] 

机构地区：[1]北京大学口腔医学院.口腔医院修复科,北京100081

出　　处：《北京大学学报（医学版）》2013年第1期44-49,共6页Journal of Peking University:Health Sciences

摘　　要：目的:分析牙槽骨高度降低对上颌前磨牙桩核冠修复后应力分布的影响,为临床桩核冠修复设计提供理论依据。方法:采用锥束CT扫描数据建立牙槽骨高度不同的上颌前磨牙桩核冠修复模型,根据牙槽骨高度将实验模型分为3组(牙槽骨高度正常、牙槽骨吸收25%、牙槽骨吸收50%),每个实验模型分别采用金合金铸造桩和玻璃纤维桩修复。用三维有限元方法对每个模型分别进行200 N的垂直加载和侧向加载,分析牙槽骨高度降低对桩核冠修复后应力分布的影响。结果:牙槽骨高度正常时牙本质内等效应力峰值最小,金属桩修复时垂直加载和侧向加载下应力峰值分别为22.570 MPa、66.354 MPa,纤维桩修复时垂直加载和侧向加载下应力峰值分别为16.480 MPa、58.103 MPa。牙槽骨吸收25%时,金属桩修复时垂直加载和侧向加载下应力峰值分别为27.690 MPa、95.192 MPa,纤维桩修复时垂直加载和侧向加载下应力峰值分别为18.260 MPa、68.452 MPa。牙槽骨吸收50%时牙本质内等效应力峰值最大,金属桩修复时垂直加载和侧向加载下应力峰值分别为37.363 MPa、135.010 MPa,纤维桩修复时垂直加载和侧向加载下应力峰值分别为24.291 MPa、110.170 MPa。结论:随着牙槽骨降低,牙本质内应力分布增加。修复材料的弹性模量会对应力分布有一定影响,但牙槽骨高度对应力分布的影响比桩核材料的影响更显著。Objective：To investigate the stress distribution of post and core restored maxillary premolm with reduced alveolar bone support. Methods： Cone-beam CT based 3-D finite element models of posl and core restored maxillary premolar were established, with 3 different alveolar bone support. Group I （control） simulated a clinical situation without horizontal bone loss. In group Ⅱ, a horizontal bone lose, of 25% and in group m of 50%were simulated. Both cast-metal post and prefabricated-fiber post were used. The influence of the alveolar bone height was investigated through three-dimensional elastic finite element static analyses by comparison of the resulting stress field, under vertical and oblique load. Locae stress measures were introduced to allow for the assessment of tooth fracture. Results： The von Miser, stress value （vertical/oblique） on dentin were measured as follows ： group I -gold = 22. 570/66. 354, group I -fiber = 16. 480/58. 103 ; group Ⅱ -gold = 27. 690/95. 192, groupⅡ -fiber = 18. 260/68. 452 ; group m-gold = 37.363/135. 010, group m-fiber = 24. 291/110. 170. Conclusion： For post and core restored teeth with horizontal bone loss, the alveolar bone support may affect the stress distribution undel vertical and oblique load. Reduction of the alveolar bone support may lead to severely increased stres, concentration in the root dentin.

关 键 词：牙应力分析 桩核技术 牙槽突 双尖牙 有限元分析 

分 类 号：R783.3[医药卫生—口腔医学]