Aim: Evaluation of different shading techniques and aging effect on translucency (contrast ratio) and surface roughness of monolithic zirconia ceramic.
Materials and Methods: Forty zirconia (Zolid High translucent) samples were constructed in the form of discs. Samples were divided according to the technique of shading into two groups as follows: The first group: Pre shaded zirconia, used as a control (n=20). The second group: Un-shaded zirconia, colored by immersion in a coloring liquid (n=20). Each group was then divided into 2 subgroups (n=10) according to the shade of samples (A2, A4). Each subgroup was furtherly subdivided into 2 subgroups(n=5) for measuring translucency (contrast ratio) & surface roughness before & after aging. Data were collected, tabulated & statistically analyzed.
Results: Results recorded no significant difference in CR value between the shading two techniques (pre-shaded & liquid-shaded) before & after aging. Whereas there was a significant difference in CR value between the two shades (A2, A4). Regarding the surface roughness, there was a non-significant difference between the pre-shaded & liquid-shaded zirconia groups, while there was a significant difference between both shades (A2 & A4) before & after aging.
Conclusions: Shade significantly affected translucency while shading technique & aging had no significant effect. Aging & shade have a significant effect on surface roughness, while there was no significant effect of the shading technique.