Influence of dentin porcelain thickness on layered all-ceramic restoration color

Abstract

Objectives: Final aesthetic performance of all-ceramic restorations is influenced by the thickness ratio of core and porcelain ceramics. This study aimed to identify and quantify the effect of increased dentin porcelain thickness on the color and color coordinates of all-ceramic specimens. Methods: Lava and IPS e.max Press all-ceramic systems were investigated. A1, A2 and A3.5 shades of layered specimens were made with 2-mm ceramic cores and 0-2 mm bevelled dentin porcelain. Color was measured at 0.05 mm dentin porcelain thickness intervals with a spectroradiometer. The effect of ceramic brand, shade and dentin porcelain thickness on color change was analyzed by 3-way ANOVA. Results: Color changes of layered ceramics varied by ceramic brand, shade and dentin porcelain thickness. For most ceramics, CIE a* and b* values gradually increased as the thickness of the dentin porcelain increased. Conversely, such increases in dentin porcelain thickness were correlated with decreasing CIE L* values. When compared with the IPS e.max Press ceramics, Lava ceramics showed smaller color changes in response to increases in dentin porcelain thickness. Conclusions: The final appearance of ceramic restorations can be manipulated by varying the dentin porcelain thickness; however, the color of the layered ceramics varied by ceramic brand, shade and dentin porcelain thickness. (C) 2010 Elsevier Ltd. All rights reserved.