Nokar Saied, Bahrami Mehran, Mostafavi Azam Sadat
Associate Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
J Dent (Tehran). 2018 Mar;15(2):69-78.
The aim of this study was to investigate the stress distribution of different post and core materials in radicular dentin by three-dimensional finite element analysis (3D FEA).
Twelve 3D models of a maxillary central incisor were simulated in the ANSYS 5.4 software program. The models were divided into three groups; the first group included: 1-Gold post and core and 2-Nickel-chromium (Ni-Cr) post and core restored with metal-ceramic restorations (MCRs). The second group included: 1-Stainless steel post, 2-Titanium post, 3-Carbon fiber post, 4-Glass fiber post, and 5-Quartz fiber post with composite cores and MCRs. The third group included: 1-Zirconia post and core, 2-Zirconia post, 3-Carbon fiber post, 4-Glass fiber post, and 5-Quartz fiber post; the last four models had composite cores restored with all-ceramic restorations (ACRs). Each specimen was subjected to a compressive load at a 45-degree angle relative to its longitudinal axis at a constant intensity of 100 N. The models were analyzed with regard to the stress distribution in dentin.
Two stress concentration sites were detected in the models. The first group showed the lowest stress levels in the cervical region, while the stress levels detected in the second group were higher than those in the first group and lower than those found in the third group. Fiber-reinforced posts induced a higher stress concentration between the middle and cervical thirds of the root compared to other posts.
According to the results, since cast posts induce lower stresses in dentin, they are recommended for clinical use. Fiber-reinforced posts and ACRs caused the maximum stresses in dentin.
本研究旨在通过三维有限元分析(3D FEA)研究不同桩核材料在根管牙本质中的应力分布。
在ANSYS 5.4软件程序中模拟了12个上颌中切牙的三维模型。这些模型分为三组;第一组包括:1-金桩核和2-镍铬(Ni-Cr)桩核并用金属烤瓷修复体(MCR)修复。第二组包括:1-不锈钢桩、2-钛桩、3-碳纤维桩、4-玻璃纤维桩和5-石英纤维桩,带有复合核和MCR。第三组包括:1-氧化锆桩核、2-氧化锆桩、3-碳纤维桩、4-玻璃纤维桩和5-石英纤维桩;最后四个模型有复合核并用全瓷修复体(ACR)修复。每个标本相对于其纵轴以45度角承受100 N恒定强度的压缩载荷。分析模型在牙本质中的应力分布。
在模型中检测到两个应力集中部位。第一组在颈部区域显示出最低的应力水平,而第二组检测到的应力水平高于第一组且低于第三组。与其他桩相比,纤维增强桩在牙根中部和颈部三分之一之间引起更高的应力集中。
根据结果,由于铸造桩在牙本质中产生的应力较低,建议临床使用。纤维增强桩和ACR在牙本质中引起最大应力。