摘要
目的:通过对临床损伤失效的全瓷修复体的损伤形貌观察,分析全瓷修复体饰瓷疲劳损伤的机制和过程,以及缺陷与饰瓷损伤的关系。方法:收集断裂或破碎的全瓷修复体,体式显微镜和扫描电子显微镜(scanning electron microscope,SEM)观察其断裂面和咬合面微观形貌以及饰瓷的缺陷,X线衍射能谱分析(energy-dispersive X-ray spectroscopy,EDS)饰瓷内不均质部分的化学成分。运用陶瓷损伤形貌分析的方法,分析全瓷修复体的断裂方式和损伤特征。结果:全瓷修复体的最终损伤失效包括完全断裂、饰瓷崩瓷和饰瓷脱瓷3种方式。氧化铝全瓷冠发生了完全断裂,氧化锆全瓷冠发生饰瓷崩瓷或饰瓷脱瓷。饰瓷疲劳损伤包括表面磨损、锥状裂纹和饰瓷脱瓷3种模式。饰瓷表面发现气孔和污染颗粒缺陷。结论:全瓷修复体应设计多点咬合接触,分散咬合应力。饰瓷脱瓷发生于饰瓷层过薄的情况,适当的饰瓷厚度保证饰瓷的抗疲劳损伤能力。临床需严格控制饰瓷烧结过程的环境污染。
Objective：To investigate the fatigue damage mechanism of porcelain,and its relation with the microscopic defects in clinically failed all-ceramic crowns.Methods： Collecting the bilayered all-ceramic crowns failed in vivo.The fractured surfaces and occlusial surfaces of failed crowns were examined by an optical microscope followed by detailed fractography investigations using a field emission scanning electron microscope.When chemical impurities were of concern,energy-dispersive X-ray spectroscopy analysis was performed to examine chemical composition.A standard practice for fractography failure analysis of advanced ceramics is applied to disclose the fracture mode,and damage character.Results： Three types of fracture features are defined as breakdown of the entire crown,and porcelain chipping-off/delamination.Alumina crowns were usually characterized by breakdown of the entire crown,while zirconia crowns by porcelain chipping-off and delamination.The fatigue damage of porcelain was classified into surface wear,cone crack,and porcelain delamination.The observed microscopic defects in this study included air bubbles and impurity particles.Conclusion： The multi-point occlusial contacts were recommended in all-ceramic restorations clinically.The thickness of porcelain is important for the anti-fatigue ability of porcelain.Cautions have to be taken to avoid contaminations during the veneering processes.
出处
《北京大学学报（医学版）》
CAS
CSCD
北大核心
2010年第1期46-49,共4页
Journal of Peking University:Health Sciences
基金
国家自然科学基金资助项目(50872003)资助~~
关键词
牙瓷料
工艺学
牙科
牙修复磨损
牙修复体
Dental porcelain
Technology
dental
Dental restoration wear
Dental prosthesis
