OBJECTIVE: This work aimed to evaluate the effect of artificial aging on the translucency and color difference (ΔE) of ultra-translucent zirconia and provide a reference for clinical application.
METHODS: The discs of ultra-translucent zirconia from six brands (Wieland, 3M ESPE, Amann Girrbach, Kuraray Noritake, Upcera, and Besmile) were cut and sintered according to each manufacturer\'s product instructions; the experimental groups were named ZNT, LVP, AG, KAT, UPC, and BSM, respectively. IPS e.max Press was used as the control group (PLT). The specimens (n=6) were prepared with a diameter of 14 mm and a thickness of 1 mm. The specimens were subjected to artificial aging treatment according to the following conditions: in an autoclave at 134 ℃ at 0.2 MPa for 4, 8, and 12 h. According to the CIE1976Lab system, the CIE L*, a*, and b* values of the specimens before and after aging were measured by a co-lorimeter. The translucency parameter (TP) and ΔE were calculated.
RESULTS: The mean TP values of each group before aging inorder were PLT>KAT>AG>ZNT>BSM>UPC>LVP. We found no significant difference in translucency in all experimental groups after aging for 4 and 8 h compared with those before aging. After 12 h of aging, the TP values of the KAT and ZNT groups were not significantly different from those before aging, but the TP values of the AG, BSM, LVP, and UPC groups were significantly lower than those before aging (P<0.05). The TP value of the control group was significantly higher than that of the other experimental groups at different stages (P<0.05). ΔE=3.3 was considered the visible color difference, and ΔE was less than 3.3 in all groups after 4 h of aging. After aging for 8 h, ΔE of the UPC group was slightly higher than 3.3. ΔE of the BSM and UPC groups was greater than 3.3 after 12 h of aging.
CONCLUSIONS: The TP and ΔE of different brands of ultra-translucent zirconia may change after various aging times. The translucency of some zirconia showed a decreasing trend and the color difference showed an increasing trend with the aging time.
目的: 探究多种常用超透氧化锆陶瓷在人工老化前后半透性和颜色的改变,为临床应用提供参考。方法: 分别将6种不同品牌(Wieland、3M ESPE、Amann Girrbach、Kuraray Noritake、爱尔创和贝施美)的超透氧化锆按照厂商产品说明进行切割及烧结,分别以ZNT、LVP、AG、KAT、UPC和BSM命名实验组,以义获嘉铸瓷作为对照组(PLT),制备成直径14 mm、厚度1 mm的试件(n=6),置于立式压力蒸汽灭菌器中,在134 ℃、0.2 MPa的标准环境下分别对各组试件进行4、8、12 h三个时段人工老化处理。采用CIE1976Lab色度系统,用电脑比色仪测量各组试件人工老化前及人工老化4、8、12 h后的CIE L*、a*、b*值,并计算半透明度(TP)及色差(ΔE)。结果: 老化前各组的TP值从大到小分别为PLT>KAT>AG>ZNT>BSM>UPC>LVP。老化4 h及8 h后,所有实验组的TP值和老化前相比差异均无统计学意义;老化12 h后,KAT组和ZNT组的TP值与老化前相比差异无统计学意义,但AG组、BSM组、LVP组和UPC组的TP值与老化前相比出现了显著性降低(P<0.05)。对照组TP值在不同阶段均显著高于实验组(P<0.05),且不受老化影响。以ΔE=3.3为肉眼可见色差,老化4 h后所有组∆E均小于3.3,老化8 h后仅有UPC组ΔE略大于3.3,老化12 h后BSM组和UPC组ΔE大于3.3。结论: 各品牌超透氧化锆在不同老化时间后,半透性和色差可能会有改变,部分氧化锆材料随着老化时间的增加半透性呈下降趋势,色差呈上升趋势。.