Verri Fellippo Ramos, Cruz Ronaldo Silva, Lemos Cleidiel Aparecido Araújo, de Souza Batista Victor Eduardo, Almeida Daniel Augusto Faria, Verri Ana Caroline Gonçales, Pellizzer Eduardo Piza
a Department of Dental Materials and Prosthodontics, Aracatuba Dental School , UNESP - Univ Estadual Paulista , Aracatuba , Brazil.
c Department of Operative Dentistry, School of Dentistry , Federal University of Alfenas - UNIFAL-MG , Alfenas , Brazil.
Comput Methods Biomech Biomed Engin. 2017 Feb;20(2):193-200. doi: 10.1080/10255842.2016.1209188. Epub 2016 Jul 13.
The aim of study was to evaluate the stress distribution in implant-supported prostheses and peri-implant bone using internal hexagon (IH) implants in the premaxillary area, varying surgical techniques (conventional, bicortical and bicortical in association with nasal floor elevation), and loading directions (0°, 30° and 60°) by three-dimensional (3D) finite element analysis. Three models were designed with Invesalius, Rhinoceros 3D and Solidworks software. Each model contained a bone block of the premaxillary area including an implant (IH, Ø4 × 10 mm) supporting a metal-ceramic crown. 178 N was applied in different inclinations (0°, 30°, 60°). The results were analyzed by von Mises, maximum principal stress, microstrain and displacement maps including ANOVA statistical test for some situations. Von Mises maps of implant, screws and abutment showed increase of stress concentration as increased loading inclination. Bicortical techniques showed reduction in implant apical area and in the head of fixation screws. Bicortical techniques showed slight increase stress in cortical bone in the maximum principal stress and microstrain maps under 60° loading. No differences in bone tissue regarding surgical techniques were observed. As conclusion, non-axial loads increased stress concentration in all maps. Bicortical techniques showed lower stress for implant and screw; however, there was slightly higher stress on cortical bone only under loads of higher inclinations (60°).
本研究的目的是通过三维（3D）有限元分析，评估在上颌前部区域使用内六角（IH）种植体、不同手术技术（传统技术、双皮质技术以及双皮质技术联合鼻底提升）和加载方向（0°、30°和60°）时，种植体支持的修复体及种植体周围骨组织中的应力分布情况。使用Invesalius、Rhinoceros 3D和Solidworks软件设计了三种模型。每个模型都包含上颌前部区域的一块骨块，其中包括一个支持金属烤瓷冠的种植体（IH，直径4×10 mm）。以不同倾斜度（0°、30°、60°）施加178 N的力。通过冯·米塞斯应力、最大主应力、微应变和位移图对结果进行分析，在某些情况下还包括方差分析统计检验。种植体、螺钉和基台的冯·米塞斯应力图显示，随着加载倾斜度的增加，应力集中增加。双皮质技术显示种植体根尖区域和固定螺钉头部的应力降低。双皮质技术在60°加载下的最大主应力和微应变图中显示皮质骨中的应力略有增加。未观察到不同手术技术在骨组织方面存在差异。结论是，非轴向载荷在所有应力图中均增加了应力集中。双皮质技术显示种植体和螺钉的应力较低；然而，仅在较高倾斜度（60°）载荷下，皮质骨上的应力略高。
