摘要
目的探讨上颌第一磨牙根管治疗后树脂充填修复和纤维桩结合树脂充填修复对其牙体及充填体的应力分布的影响。方法采用计算机体层摄影术(CT)、有限元法建立根管治疗后树脂修复(A组)及纤维桩树脂修复(B组)的上颌第一磨牙模型,以600 N总载荷垂直加载模拟最大咬合力,以200 N总载荷45°斜向加载模拟咀嚼力,分析两组模型的牙体及充填体Von Mises应力特征。结果A组、B组的牙体Von Mises应力分布模式相似,B组颊侧颈部形成应力集中,应力峰值位于釉牙骨质界;最大咬合力条件下,B组Von Mises应力峰值在牙本质外表面低于A组,内表面高于A组;咀嚼力条件下,B组Von Mises应力峰值在剩余牙体的各部位均较A组低。B组树脂充填体表面的Von Mises应力峰值及高应力区范围均明显小于A组。结论纤维桩的存在可降低牙本质及树脂充填体的应力峰值,提高患牙抗折强度,而颈部应力集中可能导致牙折发生位置偏高。
Objective To investigate the influence of the fiber post on stress distribution of endodontically-treated molars restored by resin-based composite. Methods The CT images of maxillary 1st molar of the right side were elaborated by software, and two three-dimensional finite element models of the endodontically-treated molar, restored by resin-based composite with or without a fiber post, were developed. Static loads（600 N）, simulating the maximum bite force, were applied vertically to the occlusal surfaces of the samples, while 200 N, imitating masticatory force, were applied to functional inclinations at a 45° angle. Von Mises stresses on both the tooth and the composite restoration were calculated. Results With the same load static loads applied, group A and group B had similar Von Mises stress distribution. There was always a stress concentration area on the neck of the buccal side of the tooth in group B, around the cementoenamel junction. Under the maximum bite force, the peak of Von Mises stress of group B was lower than that of group A on the outer surface of residual tooth tissue, but higher on the inner surface. Under the masticatory force, Von Mises stress value of group B was below that of group A. In both cases, stress was reduced on the composite restorations of group B. Conclusions Insertion of the fiber post could reduce stresses on both the residual tooth and the composite restoration, thus it might have some positive effect on preventing root fracture and restoration failure. Stress concentration around tooth neck indicates a higher position of tooth fracture.
出处
《中华口腔医学研究杂志（电子版）》
CAS
2014年第1期14-17,共4页
Chinese Journal of Stomatological Research(Electronic Edition)
基金
国家科技支撑计划子课题"残根残冠纤维增强树脂桩核一体化修复技术研究"(2012BAI07B01)
关键词
纤维桩
复合树脂
三维有限元
应力分析
Fiber post
Resin-based composite
Finite element analysis
Stress analysis
