烧结次数对齿科氧化锆陶瓷机械性能的影响

目的：研究不同烧结次数对氧化钇稳定四方相氧化锆（Y-TZP）陶瓷机械性能的影响。方法：制作Y-TZP瓷片，分为3组，分别烧结1、3、5次，每组再分为3个亚组，分别为在压力灭菌锅内进行水热老化处理10、20 h模拟Y-TZP的低温老化组，烧结后未进行老化的作为对照组。如此，实验共分为9组（1-10、1-20、1-C、3-10、3-20、3-C、5-10、5-20、5-C），测量每组试件的3点弯曲强度，压痕法测算其断裂韧性，并利用WEIBULL分布分析弯曲强度测量结果的可靠性。结果：9组试件的弯曲强度及断裂韧性无统计学差异（P>0.05），WEIBULL分析同样证实这一结果。结论：烧结次数的增加不会加速Y-TZP的低温老化效应，Y-TZP修复体制作过程中可能需要的多次烧结对Y-TZP材料本身的机械性能无明显影响。

Effects of multiply firings on the mechanical properties of dental Y-TZP

Objective: To evaluate the effects of multiply firings on the mechanical properties of dental yttria-stabilized tetragonal zirconia. Methods: Zirconia blocks were manufactured and divided into three groups, and each group received 1, 3, or 5 veneering porcelain firing cycles. Specimens from each firing cycle were then divided into three subgroups. Two received hydrothermal aging in an autoclave sterilizer for 10 or 20 hours, and the other group without aging as the control. The flexural strength and fracture toughness of all specimens in 9 subgroups were investigated, and the Weibull distribution was used to assess the reliability of flexural strength testing. Results: No statistical significance was found among the 9 subgroups in terms of flexural strength or fracture toughness(P>0.05) ,and the Weibull distribution demonstrated this result as well. Conclusion: Inscreased veneering porcelain firing cycles had no adverse effects on the mechanical properties of Y-TZP.