Color Stability of Glazed and Polished Dental Porcelains

Objectives: The purpose of this in vitro study was to compare the effect of the surface texture on the color stability in two types of porcelains. Methods: Forty five test specimens were prepared for each porcelains (IPS InLine® and IPS InLine PoM®,Ivoclar Vivadent AG), in the form of discs 10mm in diameter by 2-mm thick and divided into three groups for each porcelains type: Natural glaze, specimens to simulate an intraoral environment and polishing. The specimens were prepared according to their group, (n=15) and stored at 37 ºC in red wine. Color measurements were made with a spectrophotometer, at 7, 15, 21 and 30 days and color differences were determined using the CIE-LAB system and color changes (ΔE*) were then calculated. The data were analyzed with a 2-way analysis of variance (ANOVA). Results: This study show a statistically significant difference in color stability between the three groups os surface texture in each porcelains ( P=0,001). Glazed surfaces being the most stable, followed by rubber and polished surfaces with diamond polishing pastes ceramics and the less stable surfaces which were not retouched underwent no subsequent polishing treatment. Conclusions: It may be concluded that the surface texture influences the color stability of ceramic coating after 30 days of immersion in the pigmenting liquid.