Lencioni Karina Albino, Macedo Ana Paula, Silveira Rodrigues Renata Cristina, Ribeiro Ricardo F, Almeida Rossana P
Postgraduate student, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Engineer, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
J Prosthet Dent. 2015 Nov;114(5):652-9. doi: 10.1016/j.prosdent.2015.06.005. Epub 2015 Sep 4.
A misfit between the implant and metal framework can produce biomechanical problems.
The purpose of this in vitro study was to evaluate the vertical misfit, passivity, and biomechanical behavior of a prosthetic protocol-shaped I-beam framework, varying the number and inclination of implants before and after laser welding.
Two metal models with 4 or 5 implants were used. The I-beam framework for 4 or 5 implants was fabricated with cobalt-chromium alloy. The vertical misfit and passivity were evaluated with a stereomicroscope at ×80 magnification, with frameworks screwed into the respective model. The biomechanical behavior was analyzed with photoelastic studies. These analyses were performed before and after welding to observe the influence of the laser welding.
The misfit was not significantly different among the groups studied; laser welding did not influence the vertical misfit. However, when the groups were compared for passivity, the 5 implants before welding group were statistically different (P=.025).
Laser welding generated more passivity, less vertical misfit, and favorable stress distribution to the I-beam framework supported by 4 implants. To the I-beam framework supported by 5 implants laser welding did not influence the misfit or stress distribution, but there was an improvement in passivity.
种植体与金属支架之间的不匹配可能会产生生物力学问题。
本体外研究的目的是评估假体方案形状的工字梁支架的垂直不匹配、被动性和生物力学行为，在激光焊接前后改变种植体的数量和倾斜度。
使用两个带有4个或5个种植体的金属模型。用于4个或5个种植体的工字梁支架由钴铬合金制成。将支架拧入各自的模型中，用放大80倍的体视显微镜评估垂直不匹配和被动性。通过光弹性研究分析生物力学行为。在焊接前后进行这些分析，以观察激光焊接的影响。
在所研究的组中，不匹配没有显著差异；激光焊接不影响垂直不匹配。然而，在比较各组的被动性时，焊接前5个种植体的组在统计学上有差异（P = 0.025）。
激光焊接为4个种植体支持的工字梁支架产生了更高的被动性、更小的垂直不匹配和良好的应力分布。对于5个种植体支持的工字梁支架，激光焊接不影响不匹配或应力分布，但被动性有所改善。
