两种牙科陶瓷材料层状结构循环疲劳行为的对比研究

目的比较EmpressⅡ热压铸造陶瓷和GI- Ⅱ型氧化铝渗透陶瓷材料层状复合结构经Hertzian循环加载疲劳后强度的变化以及损伤模式的差异。方法应用Hertzian接触实验方法对EmpressⅡ热压铸造陶瓷和GI- Ⅱ型氧化铝渗透陶瓷标准试件进行循环加载，然后测试加载后试件的临界载荷。结果EmpressⅡ热压铸造陶瓷复合结构试件经105次循环后的临界载荷与未经循环加载组的临界载荷差别有统计学意义（P<0.05）；GI- Ⅱ型氧化铝渗透陶瓷复合结构试件在循环加载疲劳实验中，各组临界载荷变化均无统计学差别。结论GI- Ⅱ型氧化铝渗透陶瓷在循环疲劳实验中表现出较好的耐疲劳特性，可能与其材料本身的显微结构有关。EmpressⅡ热压铸造陶瓷以脆性损伤模式为主。

Compared Study of Cyclic Fatigue Behaviors in Two Kinds of Dental Ceramic Layers Structures

OBJECTIVE: To compare the difference in strength degradation and morphology damage of two dental ceramic materials after Hertzian contact cyclic fatigue. METHODS: Hertzian contact technique was used to investigate the response of Empress II glass ceramic and GI- II glass-infiltrated alumina ceramic to cyclic fatigue. Critical loads of specimens after different fatigue cycles were recorded. RESULTS: For Empress II glass ceramic, critical load had significantly difference between specimens after 10(5) cycles loading. No significant difference of critical load was found in GI- II glass-infiltrated alumina ceramic after cycles loading. CONCLUSION: GI- II glass-infiltrated alumina ceramic has better capability in resistance to cyclic loading. It may attribute to microstructure of material. Empress II glass ceramic shows a brittle damage model.