Alsadon Omar, Patrick David, Johnson Anthony, Pollington Sarah, Wood Duncan
Academic Unit of Restorative Dentistry, The School of Clinical Dentistry, The University of Sheffield.
Department of Dental Health, College of Applied Medical Sciences, King Saud University.
Dent Mater J. 2017 May 31;36(3):289-295. doi: 10.4012/dmj.2016-298. Epub 2017 Feb 11.
The objectives were to evaluate the fracture resistance and stress concentration in zirconia/composite veneered crowns in comparison to zirconia/porcelain crowns using occlusal fracture resistance and by stress analysis using finite element analysis method. Zirconia substructures were divided into two groups based on the veneering material. A static load was applied occlusally using a ball indenter and the load to fracture was recorded in Newtons (N). The same crown design was used to create 3D crown models and evaluated using FEA. The zirconia/composite crowns subjected to static occlusal load showed comparable results to the zirconia/porcelain crowns. Zirconia/composite crowns showed higher stress on the zirconia substructure at 63.6 and 50.9 MPa on the zirconia substructure veneered with porcelain. In conclusion, zirconia/composite crowns withstood high occlusal loads similar to zirconia/porcelain crowns with no significant difference. However, the zirconia/composite crowns showed higher stress values than the zirconia/porcelain crowns at the zirconia substructure.
目的是通过咬合抗折性以及使用有限元分析方法进行应力分析，来评估氧化锆/复合树脂贴面冠与氧化锆/瓷冠相比的抗折性和应力集中情况。根据贴面材料，将氧化锆基底分为两组。使用球形压头在咬合面施加静态载荷，并记录以牛顿（N）为单位的致折载荷。使用相同的冠设计创建三维冠模型，并通过有限元分析进行评估。承受静态咬合载荷的氧化锆/复合树脂冠与氧化锆/瓷冠显示出可比的结果。氧化锆/复合树脂冠在氧化锆基底上的应力较高，在瓷贴面的氧化锆基底上分别为63.6和50.9兆帕。总之，氧化锆/复合树脂冠能够承受与氧化锆/瓷冠相似的高咬合载荷，无显著差异。然而，氧化锆/复合树脂冠在氧化锆基底处的应力值高于氧化锆/瓷冠。
