Gomes Érica Alves, Gueleri Danilo Bagini, da Silva Silvio Rocha Corrêa, Ribeiro Ricardo Faria, Silva-Sousa Yara T C
Assistant Professor, School of Dentistry, University of Ribeirão Preto, São Paulo, Brazil.
Postgraduate student, School of Dentistry, University of Ribeirão Preto, São Paulo, Brazil.
J Prosthet Dent. 2015 Sep;114(3):383-9. doi: 10.1016/j.prosdent.2015.03.004. Epub 2015 May 20.
The restoration of weakened roots with glass fiber posts (GFPs) remains a challenge.
The purpose of this study was to evaluate the stress distribution of endodontically treated teeth with weakened radicular walls restored with different protocols by 3-dimensional finite element analysis (3D-FEA).
The following 4 models of endodontically treated maxillary canines restored with metal ceramic crowns were simulated on the basis of computed microtomographic images to characterize the groups: GNW (control), a nonweakened root restored with a GFP; GW, a weakened root restored with a GFP; GDA, a weakened root restored with a direct anatomic GFP; and GIA, a weakened root restored with an indirect anatomic GFP. Loads of 180 N were applied to the lingual surface on the incisal third of the teeth at 45 degrees. The models were supported by a periodontal ligament and fixed in 3 axes (x=y=z=0). The von Mises stress (VMS) was calculated.
All models exhibited VMS concentrations at the loading area and were distributed along the proximal surfaces of the root. The GFP exhibited a homogeneous stress distribution, and similar VMS distributions were observed in all of the reconstructive techniques.
Similar stress distributions were observed in the endodontically treated teeth, regardless of root weakness and the reconstructive technique for the radicular walls.
使用玻璃纤维桩(GFP)修复薄弱牙根仍然是一项挑战。
本研究的目的是通过三维有限元分析(3D-FEA)评估采用不同方案修复根管壁薄弱的根管治疗牙的应力分布。
基于计算机断层扫描图像模拟以下4种用金属烤瓷冠修复的根管治疗上颌尖牙模型以区分不同组:GNW(对照组),用GFP修复的非薄弱牙根;GW,用GFP修复的薄弱牙根;GDA,用直接解剖型GFP修复的薄弱牙根;以及GIA,用间接解剖型GFP修复的薄弱牙根。在牙齿切缘三分之一处的舌面以45度施加180 N的载荷。模型由牙周韧带支撑并在三个轴(x = y = z = 0)上固定。计算冯·米塞斯应力(VMS)。
所有模型在加载区域均表现出VMS集中,并沿牙根近中面分布。GFP表现出均匀的应力分布,并且在所有重建技术中观察到相似的VMS分布。
无论牙根薄弱情况以及根管壁的重建技术如何,在根管治疗牙中均观察到相似的应力分布。