Tripodakis A P, Strub J R, Kappert H F, Witkowski S
Department of Prosthodontics, University of Athens, Greece.
Int J Prosthodont. 1995 May-Jun;8(3):265-72.
The strength and mode of failure of three different designs of custom-made all-ceramic implant abutments fabricated by milling of In-Ceram sintered ceramic blocks were compared with the conventional CeraOne system under static load. Four test groups were formed with different locations of abutment screws. In three test groups, In-Ceram crowns were fabricated for placement on the all-ceramic abutments, and in one test group, a veneer porcelain was fired directly on the abutment; crowns in the control group were fabricated using the CeraOne system. Ten-mm-long Brånemark implants were placed into a brass block that allowed loading at a 30-degree angle to the long axis. The test group in which the veneer porcelain was fired directly on the all-ceramic abutments was the weakest, and it showed fractures at a mean value of 236 N. The fracture strength of the three other test groups was dependent on the extension of the crown margin relative to the location of the screw head. The test group that had the screw on the top compressing the entire ceramic abutment showed a mean value of 422 N that was similar to the results that were achieved with the CeraOne system (427 N). The weakest link in the all-ceramic single implant restorations was the abutment screw in which the bending began at approximately 190 N.
在静态载荷下，将通过铣削In-Ceram烧结陶瓷块制造的三种不同设计的定制全陶瓷种植体基台的强度和失效模式与传统的CeraOne系统进行了比较。根据基台螺钉的不同位置形成了四个测试组。在三个测试组中，制作In-Ceram冠用于放置在全陶瓷基台上，在一个测试组中，直接在基台上烧制饰面瓷；对照组的冠使用CeraOne系统制作。将10毫米长的Brånemark种植体植入一个黄铜块中，该黄铜块允许以与长轴成30度角的方向加载。直接在全陶瓷基台上烧制饰面瓷的测试组是最薄弱的，其在平均值236 N时出现骨折。其他三个测试组的断裂强度取决于冠边缘相对于螺钉头部位置的延伸。螺钉位于顶部压缩整个陶瓷基台的测试组的平均值为422 N，与CeraOne系统获得的结果（427 N）相似。全陶瓷单种植体修复体中最薄弱的环节是基台螺钉，其在大约190 N时开始弯曲。
