Objectives

To investigate the influence of different materials for monolithic full posterior crowns using 3D-Finite Element Analysis (FEA).

Methods

Twelve (12) 3D models of adhesively-restored teeth with different crowns according to the material and its elastic modulus were analysed: Acrylic resin, Polyetheretherketone, Composite resin, Hybrid ceramic, pressable and machinable Zirconia reinforced lithium silicate, Feldspathic, Lithium disilicate, Gold alloy, Cobalt–Chromium alloy (Co–Cr), Zirconia tetragonal partially stabilized with yttria, and Alumina. All materials were assumed to behave elastically throughout the entire deformation. Results in restoration and cementing line were obtained using maximum principal stress. In addition, maximum shear stress criteria was used for the cementing line.

Results

Restorative materials with higher elastic modulus present higher stress concentration inside the crown, mainly tensile stress on an intaglio surface. On the other hand, materials with lower elastic modulus allow stress passage for cement, increasing shear stress on this layer. Stiffer materials promote higher stress peak values.

Significance

Materials with higher elastic modulus such as Co–Cr, zirconia and alumina enable higher tensile stress concentration on the crown intaglio surface and higher shear stress on the cement layer, facilitating crown debonding.

中文翻译：

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不同全冠整体修复体的CAD-FEA建模和分析

目标

使用3D有限元分析（FEA）来研究不同材料对整块后冠的影响。

方法

根据材料及其弹性模量，对十二种不同牙冠的十二粘合式3D模型进行了分析：丙烯酸树脂，聚醚醚酮，复合树脂，杂化陶瓷，可压和可机加工的氧化锆增强硅酸锂，长石，二硅酸锂，金合金，钴铬合金（Co-Cr），由氧化钇部分稳定的四方氧化锆和氧化铝。假定所有材料在整个变形过程中都具有弹性。使用最大主应力获得修复和固井线的结果。另外，将最大剪切应力标准用于固井生产线。

结果

具有较高弹性模量的修复材料在胎冠内部呈现较高的应力集中，主要是凹版表面上的拉应力。另一方面，具有较低弹性模量的材料允许水泥通过应力，从而增加了该层上的剪切应力。较硬的材料可提高应力峰值。

意义

具有较高弹性模量的材料（例如Co-Cr，氧化锆和氧化铝）可以在胎冠凹版表面上产生更高的拉伸应力集中，并在水泥层上产生更高的剪切应力，从而促进胎冠脱胶。