背景：有观点认为根管治疗和桩核修复会增加牙齿折裂的危险，纤维桩核修复能否提高重度楔状缺损牙的抗折性能？三维有限元法可以将复杂的牙体组织简化成可被计算机分析的模型，通过对这些模型的分析进行生物力学方面的研究。目的：分析纤维桩复合树脂修复重度楔状缺损前后对牙体组织应力分布的影响。方法：建立上颌前磨牙重度楔状缺损及采用复合树脂纤维桩修复后的三维有限元模型，模拟267 N，45°斜向载荷时的受力情况，分析最大主应力的分布特征。结果与结论：重度楔状缺损模型在缺损尖端应力集中最明显。修复后模型的最大主应力分布趋势与正常牙类似，拉应力均匀分布于牙根颊面的中上部。说明纤维桩复合树脂修复有助于降低重度楔状缺损患牙颈部折裂的风险。%BACKGROUND:Someone regards that treatments such as root canal therapy and post-core restoration can increase the fracture probability of teeth. Can fiber reinforced composite post enhance the fracture resistance of the severe wedge-shaped defected premolar? Three-dimensional finite element can simplify complex dental systems into a model analyzed by computer, and conduct biomechanical research through the model analysis. OBJECTIVE:To analyze the stress distribution of sever wedge-shaped defected first premolar which restored by fiber reinforced composite post and composite resin. METHODS:We established the three-dimensional finite element models of severe wedge-shaped defected maxil ary first premolar before and after restoration with fiber reinforced composite post and composite resin. The maximum bite force was designed to 267 N that was applied at 45° angle. Then, we analyzed the distribution of maximum principal stress in finite element models. RESULTS AND CONCLUSION:The maximum principal stress was concentrated in the tip of defected region. After restoration, the distribution of maximum principal stress was similar to that of the normal premolar, and the tensile stress was distributed uniformly in the upper-central part of buccal root. It may be beneficial for improving fracture resistance ability of severe wedge-shaped-defect premolar by restoration with fiber reinforced composite post and composite resin.
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