Assunção Wirley Gonçalves, Gomes Erica Alves, Barão Valentim Adelino Ricardo, Delben Juliana Aparecida, Tabata Lucas Fernando, de Sousa Edson Antonio Capello
Department of Dental Materials and Prosthodontics, Araçatuba Dental School, University Estadual Paulista, São Paulo, Brazil.
J Craniofac Surg. 2010 May;21(3):689-95. doi: 10.1097/SCS.0b013e3181d7f2e5.
This finite element analysis study evaluated the optimal material combination for the superstructure of single implant-supported prosthesis with different fit patterns. Two models of a two-dimensional finite element analysis were constructed: group A (control), prosthesis presenting precise fit to implant; and group B, prostheses with unilateral angular misfit of 100 microm. Each group was divided into 5 subgroups according to different materials for framework (gold alloy, titanium, and zirconia) and veneering (porcelain and modified composite resin). Evaluation was performed on ANSYS software with 133-N load applied at the opposite side of misfit on the model. The load was applied with a 30-degree angulation and 2-mm off-axis. The presence of unilateral angular misfit (group B) increased the von Mises stresses in the implant (40%) and retention screw (7%) in comparison to group A. The combination of porcelain/titanium and porcelain/zirconia displayed more favorable stress distribution. When gold alloy was used as a framework material, there was no difference in stress values for both veneering materials in all groups. The use of stiffer and softer superstructures materials did not affect the stress distribution and stress values in the supporting tissue. According to the biomechanical point of view, materials with high elasticity modulus are more suitable for the superstructure of implant-supported prosthesis.
这项有限元分析研究评估了具有不同贴合模式的单颗种植体支持修复体上部结构的最佳材料组合。构建了二维有限元分析的两种模型：A组（对照组），修复体与种植体呈现精确贴合；B组，修复体存在100微米的单侧角度不贴合。每组根据框架（金合金、钛和氧化锆）和饰面（瓷和改性复合树脂）的不同材料分为5个亚组。在ANSYS软件上进行评估，在模型不贴合的对侧施加133 N的载荷。载荷以30度角和2毫米离轴施加。与A组相比，单侧角度不贴合（B组）的存在使种植体中的冯·米塞斯应力增加了40%，固位螺钉中的应力增加了7%。瓷/钛和瓷/氧化锆的组合显示出更有利的应力分布。当使用金合金作为框架材料时，所有组中两种饰面材料的应力值没有差异。使用更硬和更软的上部结构材料不会影响支持组织中的应力分布和应力值。从生物力学角度来看，具有高弹性模量的材料更适合种植体支持修复体的上部结构。
