Sertgöz A
Department of Prosthodontics, Faculty of Dentistry, University of Marmara, Istanbul, Turkey.
Int J Prosthodont. 1997 Jan-Feb;10(1):19-27.
This study used three-dimensional finite element analysis to investigate the effect of three different occlusal surface materials (resin, resin composite, and porcelain) and four different framework materials (gold, silver-palladium, cobalt-chromium, titanium alloys) on the stress distribution in a six-implant-supported mandibular fixed prosthesis and surrounding bone. A total of 172 N vertical load was distributed over the entire occlusal surface of the finite element model. Generated stress values were calculated in the occlusal surface material, framework, prosthesis retaining screws, implants, and surrounding cortical and spongy bones. The results obtained demonstrated that using a prosthesis superstructure material with a lower elastic modulus (1) did not lead to substantial differences in stress patterns nor in values at the cortical and spongy bones surrounding the implants; and (2) concentrated stresses in the retaining screws for the prosthesis and thus increased the potential risk of prosthesis failure. For the single loading condition investigated, the optimal combination of materials was found to be cobalt-chromium for the framework and porcelain for the occlusal surface.
本研究采用三维有限元分析方法，研究三种不同的咬合面材料（树脂、树脂复合材料和陶瓷）以及四种不同的支架材料（金、银钯合金、钴铬合金、钛合金）对下颌骨六种植体支持式固定义齿及其周围骨组织应力分布的影响。在有限元模型的整个咬合面上施加了总计172 N的垂直载荷。计算了咬合面材料、支架、义齿固位螺钉、种植体以及周围皮质骨和松质骨中的应力值。所得结果表明，使用弹性模量较低的义齿上部结构材料：（1）不会导致种植体周围皮质骨和松质骨的应力模式及应力值出现显著差异；（2）会使义齿固位螺钉处的应力集中，从而增加义齿失败的潜在风险。对于所研究的单一加载条件，发现材料的最佳组合是钴铬合金支架和陶瓷咬合面。
