服役环境对牙科氧化锆陶瓷可靠性和疲劳性能的影响

The effects of service environment on the reliability and fatigue performance of dental zirconia ceramics

目的:探讨服役环境对牙科氧化锆陶瓷弯曲强度可靠性和疲劳性能的影响。方法:将60个烧结好的锆瓷试样随机分成4组(A、AF、B和BF,n=15),对试样表面打磨、抛光。A组的弯曲试验在空气环境下进行,B组在人工唾液中进行。使用独立样本T检验分析A、B组弯曲强度的统计学差异,使用Weibull函数分析A、B组弯曲强度的可靠性。AF组的疲劳试验在空气环境中进行,BF组在37℃的人工唾液中进行。结果:A组和B组的弯曲强度分别为(1198.88±118.22)MPa和(1139.56±143.67)MPa(P>0.05);A组、B组弯曲强度的Weibull模数分别为11.85和9.61;AF组和BF组试样发生亚临界裂纹扩展时的应力强度因子分别为2.77 MPa·m^(1/2)和2.65 MPa·m^(1/2)。结论:在人工唾液中,牙科氧化锆陶瓷弯曲强度的可靠性和疲劳性能降低。

Objective:To investigate the effects of service environment on the reliability and fatigue properties of dental zirconia ceramics.Methods:60 bar-shaped specimens of dental zirconia ceramics were fabricated and randomly assigned to 4 groups(A,AF,B and BF,n=15).The surface of the samples was polished.The three-point bending test was carried out in dry environment,and in artificial saliva for group A and B respectively.The bending strength of group AF and BF were compared with independent t-test and the strength reliability was analyzed by Weibull statistics.Then the three-point bending fatigue test was carried out in air environment and in artificial saliva at 37℃for group AF and BF respectively.Results:The bending strength of group A and B was(1198.88±118.22)MPa and(1139.56±143.67)MPa(P>0.05)respectively.The Weibull modulus of bending strength of A and B were 11.85 and 9.61 respectively.The stress intensity factors of AF and BF was 2.77 MPa·m^(1/2) and 2.65 MPa·m^(1/2) respectively.Conclusion:In artificial saliva,the reliability and fatigue performance of dental zirconia ceramics decreases.