Spazzin A O, Galafassi D, de Meira-Júnior A D, Braz R, Garbin C A
Department of Prosthotondics and Periodontics, School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil.
Oper Dent. 2009 Mar-Apr;34(2):223-9. doi: 10.2341/08-73.
The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm2 was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 microm). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes.
本研究采用有限元分析（FEA），评估了两种根管桩系统以及树脂水门汀的弹性模量和膜厚度对上颌中切牙（MCI）直接树脂复合材料修复后应力分布的影响。构建了一个带有冠折和支持结构的MCI三维模型。在复合树脂修复体的腭面两个区域施加2.16 N/mm²的静态咀嚼压力。考虑了氧化锆陶瓷（ZC）桩和玻璃纤维（GF）桩。当使用不同弹性模量（7.0和18.6 GPa）和不同层厚度（70和200微米）的树脂水门汀将ZC桩和GF桩固定到根管中时，分析了桩、牙本质和水门汀层中的应力分布。不同的桩材料对应力分布有显著影响，使用GF桩时应力集中较小。弹性模量较高的水门汀自身产生的应力水平较高。水门汀厚度没有显著变化。
