Güngör Merve B, Nemli Seçil K, Bal Bilge T, Tamam Evşen, Yılmaz Handan, Aydın Cemal
Department of Prosthodontics, Faculty of Dentistry, Gazi University.
J Oral Sci. 2019 Jun 18;61(2):246-254. doi: 10.2334/josnusd.18-0060. Epub 2019 Apr 22.
This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group). The aging process included both thermocycling and mechanical loading and was followed by fracture resistance testing. All specimens in the M-E, M-TZI, and V-L groups survived; however, all specimens in the V-P group were fractured during artificial aging. The highest fracture resistance values were observed in the M-TZI group. According to the fracture resistance test, connector fractures were the most frequent type of failure. M-TZI and M-E FDPs revealed no failures during aging and showed higher fracture resistance than the veneered groups. Among the veneered zirconia framework groups, V-L FDPs showed the highest success rate during aging, while the fracture resistance was similar among all the veneered zirconia groups.
本研究比较了在咀嚼模拟器中老化后，通过计算机辅助设计/计算机辅助制造（CAD/CAM）制作的整体式和贴面式全瓷四单位后牙固定义齿（FDPs）的抗折性。从六种不同的全瓷系统设计了四单位FDPs：1）整体式二硅酸锂（M-E），2）整体式氧化锆（M-TZI），3）通过传统分层法制作的贴面氧化锆（V-L），4）通过二硅酸锂压制法制作的贴面氧化锆（V-P），5）通过二硅酸锂熔合法制作的贴面氧化锆（CAD-F-E），6）通过长石质陶瓷粘结法制作的贴面氧化锆（CAD-C-CB）。将标本分为对照组和老化组（每组n = 10）。老化过程包括热循环和机械加载，随后进行抗折性测试。M-E、M-TZI和V-L组的所有标本均存活；然而，V-P组的所有标本在人工老化过程中均发生骨折。M-TZI组观察到最高的抗折性值。根据抗折性测试，连接体骨折是最常见的失败类型。M-TZI和M-E FDPs在老化过程中未出现失败，并且显示出比贴面组更高的抗折性。在贴面氧化锆框架组中，V-L FDPs在老化过程中显示出最高的成功率，而所有贴面氧化锆组的抗折性相似。
