Effect of immersion in coffee on the color stability and translucency of multilayered zirconia

Abstract

Statement of the problem: The optical properties and translucency parameter of multilayered zirconia based ceramic restoration may be affected by coffee.Objectives: The aim of this study was to investigate the impact of coffee immersion on color stability and translucency parameter of multi-layered zirconia.Materials and methods: Three translucent zirconia brands (Ceramill Zolid fx Multilayer, IPS e.max ZirCAD Prime and KATANA YML Yttria Multi Layered) were tested for this study (n=10). Zirconia specimens were initially designed to achieve postsintering dimensions: 10×10 mm diameter and 1 mm thickness. CAD/CAM milling machine (Coritec 150i PRO, Imes-Icore GmbH, Germany) was used for milling of each brand of zirconia. The specimens underwent sintering and further glazed (Programat P300; Ivoclar Vivadent AG). The color coordinates, color difference (ΔΕ) and the translucency parameter (TP) prior to and after coffee thermocycling were analyzed with a spectrophotometer. Data were analyzed using 1-way ANOVA, 2-way ANOVA and Paired t-test at p value ≤ 0.05. Results: Statistical significant difference were observed for all measured L*, a*, and b* color coordinates and (TP) values after coffee thermocycling for all multi-layered zirconia groups (P<0.001). KATANA YML group showed the lowest (TP) value and highest (ΔΕ) irrespective of the variable being examined.Conclusions: Both color and translucency of multi-layered zirconia may vary depending on the brand used. The coffee thermocycling had an impact on the color and translucency of multi-layered zirconia, yet it remained within the clinical acceptable threshold of color difference.