Color stability of dental composites as a function of shade

Abstract

Statement of problem. The selection of shade of composites for restorative applications may have a significant effect on color degradation through environmental exposure. Purpose. This study characterized the color changes in composites as a function of shade through environmental effects such as ultraviolet light exposure. Material and methods. Five shades of two composites were subjected to ultraviolet light exposure at 37° C for 24 hours after initial storage for 24 hours in distilled water at 37° C. The lightness and chromaticity values of color were measured both before and after ultraviolet light exposure with a Minolta Chromameter. The total color change as well as changes in the lightness and chromaticity values were measured in the CIE L*a*b* scale and analyzed to monitor color degradation, if any. Results. Color degradation was a significant function of shade and occurred primarily as an increase in yellowness. Color changes increased with the lightness of the shade in both composite systems. Conclusion. The lighter shades of composites were likely to be subject to higher color degradation through environmental effects of ultraviolet light exposure. (J Prosthet Dent 1998;79:372-7.)