Department of Prosthodontics, Faculty of Dentistry, Kocaeli University, Başiskele, Kocaeli, Turkey.
J Prosthodont. 2020 Feb;29(2):166-172. doi: 10.1111/jopr.13019. Epub 2019 Jan 24.
To investigate the color stability of zirconia-reinforced lithium silicate glass-ceramic and lithium disilicate reinforced glass-ceramic, which were prepared with various surface finishing procedures, following 1-week, 2-week, 1-month, and 2-month storage in various beverages, and after the application of polishing paste.
Lithium disilicate glass-ceramic (IPS e.max CAD HT) and zirconia-reinforced lithium silicate ceramic (Vita Suprinity HT) CAD/CAM blocks were sectioned with a diamond saw (Metkon) under water cooling into 1.5 × 7 × 12 mm dimensions (N = 120). All specimens were polished with silicon carbide paper (600-, 800-, and 1200-grit) under water for 120 seconds. The specimens were prepared using 3 surface finishing procedures: glaze, mechanical polishing, and external staining and glaze in accordance with manufacturers' instructions. Then, each group was divided into 2 storage subgroups, black tea and coffee (n = 10/group). Color values were measured in CIELAB color space with dental spectrophotometer (VITA Easyshade) at the initial stage, and following 1-week, 2-week, 1-month, 2-month storage, and after fine-grit polishing paste application (Proxyt). Color changes (ΔE) were calculated and statistically analyzed using ANOVA followed by Bonferroni corrected post-hoc tests using Number Cruncher Statistical System 2007 (α < 0.05).
For lithium disilicate glass-ceramic, glaze procedure showed statistically lower color change values than mechanical polishing and external staining and glaze surface finishing groups (p < 0.05) following storage in both beverages, whereas for zirconia-reinforced lithium silicate ceramic, glaze procedure showed statistically lower color change values than mechanical polishing, but statistically insignificant values with respect to external staining and glaze group, following storage in both beverages. Lithium disilicate glass-ceramic groups showed statistically lower or statistically insignificant color change values with respect to zirconia-reinforced lithium silicate ceramic groups, except for the external staining and glaze surface finishing group in coffee. Significantly lower discoloration values were obtained following polishing paste application, with respect to 2-month storage in beverages (p < 0.05).
Glazing alone led to more color stability with respect to mechanical polishing and external staining and glaze for zirconia-reinforced lithium silicate and lithium disilicate glass-ceramic. Lithium disilicate glass-ceramic showed higher color stability compared to zirconia-reinforced lithium silicate ceramic. Polishing paste resulted in a decrease in discoloration to clinically acceptable values.
研究经过不同表面处理程序制备的氧化锆增强锂硅玻璃陶瓷和二硅酸锂增强玻璃陶瓷在经过 1 周、2 周、1 个月和 2 个月的储存后，以及在应用抛光膏后，在各种饮料中的颜色稳定性。
将二硅酸锂玻璃陶瓷（IPS e.max CAD HT）和氧化锆增强锂硅陶瓷（Vita Suprinity HT）CAD/CAM 块用金刚石锯（Metkon）在水下冷却切成 1.5×7×12mm 的尺寸（N=120）。所有样本均用碳化硅砂纸（600、800 和 1200 目）在水下打磨 120 秒。根据制造商的说明，使用 3 种表面处理程序对样本进行处理：上釉、机械抛光和外部染色上釉。然后，将每组分为 2 个储存亚组，红茶和咖啡（每组 n=10）。使用牙科分光光度计（VITA Easyshade）在初始阶段和经过 1 周、2 周、1 个月、2 个月的储存以及使用细粒度抛光膏（Proxyt）应用后，在 CIELAB 颜色空间中测量颜色值。使用 Number Cruncher Statistical System 2007（α<0.05）计算颜色变化值（ΔE），并使用方差分析和 Bonferroni 校正后检验进行统计分析。
对于二硅酸锂玻璃陶瓷，与机械抛光和外部染色上釉表面处理组相比，上釉处理组在两种饮料储存后表现出统计学上更低的颜色变化值（p<0.05），而对于氧化锆增强锂硅陶瓷，上釉处理组与机械抛光组相比表现出统计学上更低的颜色变化值，但与外部染色上釉组相比则无统计学意义。与氧化锆增强锂硅陶瓷相比，除了咖啡中的外部染色上釉组外，二硅酸锂玻璃陶瓷组在储存于两种饮料中时表现出统计学上更低或无统计学意义的颜色变化值。与储存于饮料中 2 个月相比，使用抛光膏后可获得更低的变色值（p<0.05）。
对于氧化锆增强锂硅和二硅酸锂玻璃陶瓷，单独上釉可使机械抛光和外部染色上釉的颜色稳定性更高。与氧化锆增强锂硅陶瓷相比，二硅酸锂玻璃陶瓷具有更高的颜色稳定性。抛光膏可使变色值降低到临床可接受的水平。
