【摘要】 目的:应用有限元法研究牙本质肩领高度对纤维桩核冠修复的上颌中切牙应力大小和分布的影响。方法:通过螺旋CT扫描和有限元软件,建立不同牙本质肩领高度(3m m、2m m、1.5m m、1.0m m、0.5m m、0m m)的纤维桩+全瓷冠修复的上颌中切牙三维有限元模型。模拟咬合加载,记录牙本质、全瓷冠、纤维桩、树脂粘接剂,以及牙周膜和牙槽骨的Von Mises应力和最大拉应力。结果:当牙本质肩领从3m m降至1.5m m时,牙本质和全瓷冠的Von Mises应力和最大拉应力变化不明显,从1.5m m降至0m m时,应力值逐渐增大并出现应力集中的趋势,尤其是从0.5m m降至0m m时最明显;随着牙本质肩领高度降低,纤维桩、树脂粘接剂、牙周膜和牙槽骨的应力大小和分布均无明显变化。结论:牙本质肩领结构可以降低牙本质和全瓷冠的应力峰值;修复严重缺损上颌中切牙时,建议至少保留0.5m m的肩领结构。更多还原

【Abstract】 Objective: To evaluate the effect of dentin collar height on stress distribution of fiber post-all-ceramic crown restored maxillary central incisor, with application of finite element method. Methods: Three dimensional finite element models of fiber post- all-ceramic crown restored maxillary central incisor with different collar height(3mm, 2mm, 1.5mm,1.0mm, 0.5mm, 0mm) were established using spiral CT scanning and finite element software. The Von Mises stress and maximum tensile stress of dentin, all-ceramic crown, fiber post, resin bonding agent, periodontal ligament and alveolar bone were recorded by simulation of occlusal loading. Results: With dentin collar height from 3mm to 1.5mm, the Von Mises stress and maximum tensile stress of dentin and all-ceramic crown did not significantly change. With dentin collar height from 1.5mm to 0mm, the stress value gradually increases and appears stress concentration trend, especially from 0.5mm to0 mm. With reduction of dentin collar height, the stress value and distribution of fiber post, resin bonding agent, periodontal ligament and alveolar bone showed no significant alteration. Conclusion: The dentin collar structure decreases the stress peak of dentin and all-ceramic crown. At least 0.5mm for Collar structure is suggested for restoration of severely defected maxillary central incisor.更多还原