Department of Dental Materials and Biomaterials Research, University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.
J Biomed Mater Res B Appl Biomater. 2010 Oct;95(1):202-6. doi: 10.1002/jbm.b.31703.
Zirconia (Y-TZP) is used as material for components of implants and prostheses because of its high short-term strength. The mechanical long-term reliability, however, is limited for Y-TZP because of hydrothermal aging effects and a pronounced tendency for subcritical crack growth. The hypothesis of this study was that a substantial amount of alumina in a zirconia matrix can help to significantly suppress subcritical crack growth and thereby improve the mechanical long-term reliability. The Weibull parameters as well as the parameters of the subcritical crack growth were determined for Alumina, Y-TZP, and two dispersion ceramics, that is Alumina Toughened Zirconia (ATZ, 20% alumina/80% Y-TZP), and Zirconia Toughened Alumina (ZTA, 75% alumina/25% Y-TZP). The long-term failure probability as a function of service time was predicted for the four ceramics. The parameter n of the subcritical crack growth was approx. 80% higher for ATZ compared to Y-TZP. In consequence, the estimated lifetime revealed a significant better mechanical long-term reliability for ATZ. It can be concluded that tailored dispersion oxide ceramics can address the aging problem of monolithic zirconia. This makes ATZ very interesting for components of joint replacement as well as for dental prostheses and implants.
氧化锆（Y-TZP）因其短期强度高而被用作植入物和假体部件的材料。然而，由于湿热老化效应和亚临界裂纹扩展的明显趋势，Y-TZP 的机械长期可靠性有限。本研究的假设是，氧化锆基体中大量的氧化铝可以帮助显著抑制亚临界裂纹扩展，从而提高机械长期可靠性。确定了氧化铝、Y-TZP 以及两种分散陶瓷（氧化铝增韧氧化锆（ATZ，20%氧化铝/80%Y-TZP）和氧化锆增韧氧化铝（ZTA，75%氧化铝/25%Y-TZP）的威布尔参数以及亚临界裂纹扩展参数。预测了四种陶瓷的长期失效概率作为服务时间的函数。与 Y-TZP 相比，ATZ 的亚临界裂纹扩展参数 n 约高 80%。因此，估计的使用寿命表明 ATZ 的机械长期可靠性有显著提高。可以得出结论，定制的分散氧化物陶瓷可以解决整体氧化锆的老化问题。这使得 ATZ 非常适合关节置换部件以及牙科修复体和植入物。
