中文摘要：

目的：体外试验的方法对比分析颈环和非颈环设计的叠层氧化锆全瓷冠的破碎失效模式和过程,并与临床实际叠层氧化锆全瓷修复体的破碎失效模式对比.方法：临床常规方法制作叠层氧化锆全瓷冠,粘接于树脂基牙上,万能实验机上进行破碎实验,对比常规和颈环基底冠设计的氧化锆全瓷冠的抗力,体式显微镜和扫描电子显微镜观察破碎失效模式和特征.结果：2 mm颈环基底冠设计的氧化锆全瓷冠破碎失效时的承载力值大于常规基底冠设计的氧化锆全瓷冠,所有破碎失效的氧化锆全瓷冠都只发生饰瓷破坏,而没有发生氧化锆基底冠的破坏.破碎失效方式分为3种：饰瓷裂纹、饰瓷崩瓷、饰瓷脱瓷,各种破碎失效方式的分布情况在两种设计的氧化锆全瓷冠中差异无统计学意义,发生脱瓷的氧化锆全瓷冠最多,发生饰瓷崩瓷的最少.结论：在单次载荷条件下,2 mm颈环基底冠设计提高了叠层氧化锆全瓷修复体的抗力;叠层氧化锆全瓷冠在单次载荷条件下的破坏方式与临床见到的疲劳载荷下的氧化锆全瓷修复体损伤失效模式基本相同,表现为崩瓷和氧化锆基底冠暴露.

英文摘要：

Objective： To study the fracture resistance and characteristics of the bi-layer zirconia all ce- ramic crowns according to the zirconia coping design using various experimental methods and to compare the results of the in vitro test with the clinical evaluation. Methods：The bi-layer zirconia all ceramic crowns were fabricated by the same method as used in clinical practice. Two different coping designs with/without zirconia marginal collar were used. All the samples were cemented onto corresponding resin dies. All the specimens were tested in the 2 groups with/without zirconia collar. The fracture load test was performed on 10 crowns from each group. Fracture strength was tested with a universal testing ma- chine. The fracture modes and features of the failed crowns were observed with an integrated microscope and a field emission scanning electron microscope. Results：The zirconia collar group showed higher frac- ture load than the group without zirconia collar. All the zirconia crowns failed with porcelain failure and without zirconia coping broken. The porcelain fracture modes were crack, chipping and delamination. The distribution of the different fracture modes in the groups was the same. Conclusion： The bi-layer zir- conia crown with 2 mm zirconia marginal collar showed more fracture strength under once load. The frac- ture modes of the test specimens were the same as the clinical fracture hi-layer zirconia crowns, showing porcelain chipping and delamination.