硬腭骨膜下种植体修复单侧无牙上颌骨缺损中基台设计的有限元分析

Analysis of three-dimensional finite element in the abutment design of the palatal subperiosteal implant in the rehabilitation of the unilateral edentulous maxillary defect

目的:对支持单侧上颌赝复体的硬腭骨膜下种植体基台数量及分布进行优化设计。方法:建立目标三维有限元模型,分别对6、5、4、3、2个基台共15种设计方案进行双侧加载测试,对比观测其健侧颌骨6个不同部位骨皮质内最大von Mises应力。用简化模型计算各类设计中健侧基台上的最大脱位力。结果:5基台与6基台设计骨应力反应无明显差异;4基台设计中Ⅳb、3基台设计中IIIa、2基台设计中IIa方案在同组方案中骨应力反应最佳,前二者甚至接近6基台设计。各类设计中健侧分布靠前的基台上产生的脱位力较大,反之较小。结论:Ⅳb和IIIa是此类骨膜下种植体较理想的基台设计方案。

Objective To optimize the abutment design of the palatal subperiosteal implant in the rehabilitation of the unilateral edentulous maxillary defect. Methods A three-dimensional finite element model of the rehabilitated right defective maxillae using palatal subperiosteal implant was constructed. Fifteen implants with from 2 to 6 abutments were designed. Bilateral loads on the denture of the obturator were simulated and the maximal von Mises stress values in the cortical bone of six sites of the left maxillae were investigated. The maximal dislocating forces applied on the left abutments of every implant were evaluated using a simplified model. Results There was no evident difference in the stress level between 6-abutment and 5-abutment implants. Relatively lower stress values of implant Ⅳ b,Ⅲa and Ⅱa were observed in the 4-abutment, 3-abutment and 2-abutment implants respectively. Furthermore, the stress values of implant Ⅳ b and Ⅲa were comparable with those of 6-abutment implant. The maximal dislocating forces on anterior abutments were greater than those on posterior abutments. Conclusion With 4 and 3 abutments respectively, implant Ⅳb and Ilia are more suitable in the rehabilitation of the unilateral defective edentulous maxillae.