Carvalho Marco Aurélio, Sotto-Maior Bruno Salles, Del Bel Cury Altair Antoninha, Pessanha Henriques Guilherme Elias
Doctoral student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil.
Professor, Department of Restorative Dentistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
J Prosthet Dent. 2014 Nov;112(5):1096-102. doi: 10.1016/j.prosdent.2014.03.015. Epub 2014 May 13.
Although various abutment connections and materials have recently been introduced, insufficient data exist regarding the effect of stress distribution on their mechanical performance.
The purpose of this study was to investigate the effect of different abutment materials and platform connections on stress distribution in single anterior implant-supported restorations with the finite element method.
Nine experimental groups were modeled from the combination of 3 platform connections (external hexagon, internal hexagon, and Morse tapered) and 3 abutment materials (titanium, zirconia, and hybrid) as follows: external hexagon-titanium, external hexagon-zirconia, external hexagon-hybrid, internal hexagon-titanium, internal hexagon-zirconia, internal hexagon-hybrid, Morse tapered-titanium, Morse tapered-zirconia, and Morse tapered-hybrid. Finite element models consisted of a 4×13-mm implant, anatomic abutment, and lithium disilicate central incisor crown cemented over the abutment. The 49 N occlusal loading was applied in 6 steps to simulate the incisal guidance. Equivalent von Mises stress (σvM) was used for both the qualitative and quantitative evaluation of the implant and abutment in all the groups and the maximum (σmax) and minimum (σmin) principal stresses for the numerical comparison of the zirconia parts.
The highest abutment σvM occurred in the Morse-tapered groups and the lowest in the external hexagon-hybrid, internal hexagon-titanium, and internal hexagon-hybrid groups. The σmax and σmin values were lower in the hybrid groups than in the zirconia groups. The stress distribution concentrated in the abutment-implant interface in all the groups, regardless of the platform connection or abutment material.
The platform connection influenced the stress on abutments more than the abutment material. The stress values for implants were similar among different platform connections, but greater stress concentrations were observed in internal connections.
尽管最近引入了各种基台连接方式和材料，但关于应力分布对其力学性能影响的数据仍然不足。
本研究的目的是采用有限元方法研究不同基台材料和平台连接方式对单颗前牙种植支持修复体应力分布的影响。
通过3种平台连接方式（外六角形、内六角形和莫氏锥度）和3种基台材料（钛、氧化锆和混合型）的组合构建9个实验组，如下：外六角形-钛、外六角形-氧化锆、外六角形-混合型、内六角形-钛、内六角形-氧化锆、内六角形-混合型、莫氏锥度-钛、莫氏锥度-氧化锆和莫氏锥度-混合型。有限元模型包括一个4×13毫米的种植体、解剖型基台以及粘结在基台上的二硅酸锂中切牙冠。分6步施加49 N的咬合负荷以模拟切导。采用等效应力（σvM）对所有组的种植体和基台进行定性和定量评估，并采用最大主应力（σmax）和最小主应力（σmin）对氧化锆部件进行数值比较。
基台的最高σvM出现在莫氏锥度组，最低出现在外六角形-混合型、内六角形-钛和内六角形-混合型组。混合型组的σmax和σmin值低于氧化锆组。无论平台连接方式或基台材料如何，所有组的应力分布均集中在基台-种植体界面。
平台连接方式对基台应力的影响大于基台材料。不同平台连接方式下种植体的应力值相似，但内部连接方式下观察到更大的应力集中。
