关键词: 金合金, 金钯合金, 氧化锆, 抗折强度

Abstract:

Abstract：Objective To compare the flexural strength of Y-TZP all-ceramic crowns and two other different precious metals porcelain crowns. Methods Fifteen master tooth analogs were prepared resembling a molar crown preparation using the precision lathe and were divided into 3 groups.Five wax patterns were made from the mold and cast in a Au-Pd alloy，from which five Au-Pd metal-ceramic crowns were fabricated. Another 5 high-noble alloy metal-ceramic crowns and 5 ZrO2 all-ceramic were made from the same metal die.Each crown group were made in accordance with the specific manufacture’s instructions.All specimens were cemented on the analogs.Their fracture resistance was tested in a universal machine.A stainless steel rod with a 5-mm diameter stainless-steel ball was vertically placed on the occlusal surface of the crowns and at a speed of 0.5mm/min.Fracture was de?ned as occurrence of chipping.The loads at fracture were registered，and differences between the groups were calculated using One-way ANOVA. Results Au-Pd（3.932 ± 0.27）kN；Au（2.280 ± 0.20）kN；ZrO2（2.08 ± 0.18）kN. Significant differences in flexural strength between Au-Pd and other two groups were observed（P < 0.05），while there was no significant difference between the ZrO2 and high-noble group（P > 0.05）.Conclusion Au-Pd group shows significantly greater flexural strength than high-noble and ZrO2 ceramic restorations（P < 0.05），while there's no significant difference between the ZrO2 and high-noble（P > 0.05）.

Key words: high-noble alloy, Au-Pd, zirconia, flexural strength