The Effect of Aging on Color stability and Translucency of two different ceramic Materials

Abstract

Increased demand for achieving the best esthetics in dentistry has led to an increase in the use of different types of ceramic materials particularly the CAD/CAM ceramics which become more popular. The final restoration color may be influenced by the thickness and translucency of the veneer restoration, depending on the amount of light scattering and reflection. Therefore, shade selection of thin restorations like laminate veneers is considered a challenge. The effect of Aging and different thicknesses of different ceramics on color changes and translucency were evaluated in this study. Two new ceramic materials indicated for thin laminate veneers and esthetic crowns were used in this study which were Lithium disilicate and ultra-translucent zirconia. The materials were then cut into 28 square shaped samples by using Isomet. The samples were divided into two main groups according to type of ceramic materials into group (E) = 14 samples and group (Z) = 14 samples. The two main groups were subdivided into two subgroups for each according to the thickness into group (EI) with 0.5 mm thickness = 7 samples, group (EII) with 1 mm thickness = 7 samples, group (ZI) with 0.5 mm thickness = 7 samples and group (ZII) with 1mm thickness=7 samples. The samples were then examined by Aligent Cary 5000 spectrophotometer to measure color and translucency. The samples were then exposed to thermocycling device to stimulate aging. After aging, color and translucency were then measured. The samples were