de Castro Gabriela Cassaro, de Araújo Cleudmar Amaral, Mesquita Marcelo Ferraz, Consani Rafael Leonardo Xediek, Nóbilo Mauro Antônio de Arruda
Department of Prosthodontics and Periodontics, Piracicaba Dental School, UNICAMP - University of Campinas, Piracicaba, SP, Brazil.
Braz Dent J. 2013;24(2):147-51. doi: 10.1590/0103-6440201302112.
Lack of passivity has been associated with biomechanical problems in implant-supported prosthesis. The aim of this study was to evaluate the passivity of three techniques to fabricate an implant framework from a Co-Cr alloy by photoelasticity. The model was obtained from a steel die simulating an edentulous mandible with 4 external hexagon analog implants with a standard platform. On this model, five frameworks were fabricated for each group: a monoblock framework (control), laser and TIG welding frameworks. The photoelastic model was made from a flexible epoxy resin. On the photoelastic analysis, the frameworks were bolted onto the model for the verification of maximum shear stress at 34 selected points around the implants and 5 points in the middle of the model. The stresses were compared all over the photoelastic model, between the right, left, and center regions and between the cervical and apical regions. The values were subjected to two-way ANOVA, and Tukey's test (α=0.05). There was no significant difference among the groups and studied areas (p>0.05). It was concluded that the stresses generated around the implants were similar for all techniques.
在种植体支持的修复体中，缺乏被动性与生物力学问题相关。本研究的目的是通过光弹性评估三种用钴铬合金制作种植体框架的技术的被动性。模型取自一个模拟无牙下颌骨的钢模，带有4个标准平台的外部六边形模拟种植体。在这个模型上，每组制作5个框架：一个整体框架（对照）、激光焊接框架和TIG焊接框架。光弹性模型由柔性环氧树脂制成。在光弹性分析中，将框架用螺栓固定在模型上，以验证种植体周围34个选定位置和模型中间5个位置的最大剪应力。在整个光弹性模型上、左右和中间区域之间以及颈部和根尖区域之间比较应力。对这些值进行双向方差分析和Tukey检验（α=0.05）。各研究组和研究区域之间没有显著差异（p>0.05）。得出的结论是，所有技术在种植体周围产生的应力相似。
