EFFECT OF SURFACE FINISHING AND DIFFERENT IMMERSION MEDIA ON THE COLOR STABILITY AND SURFACE ROUGHNESS OF VITA LUMEX VENEERING ZIRCONIA (An In-vitro study)

Aim: The aim of the present study was to evaluate the effect of surface finishing and staining solutions and surface roughness of Vita lumex veneering zirconia.Methodology: 42 square specimens of 10 mm width, length and 2 mm height (1 mm for zirconia substructure & 1 mm for veneering materials) were sectioned. All the specimens were ground with 40 μm diamond grinding stones to simulate intra oral occlusal adjustment, then randomly divided into 2 equal groups according to surface finish either polishing or glazing. Before immersion, baseline readings for color and surface roughness were registered for all specimens. Each group was randomly subdivided into three subgroups according to the immersion solution used either: coffee, citric acid or artificial saliva. Surface roughness measurements were achieved using a non-contact profilometer and a color estimation of all specimens was done by reflective spectrophotometer.Results: Regarding glazed surfaces, there were insignificant differences in roughness in all immersion solutions before (P=0.84), and after (P=45). Regarding polished surfaces, there were insignificant differences in roughness in all immersion solutions before (P=0.79), and after (P=39). While regarding the color changes for both surface treatments (ΔE2000), artificial saliva was significantly the lowest, then citric acid, while coffee demonstrated significantly the highest color changes.Conclusions: Coffee had the greatest influence on the color of polished and glazed used ceramics, but it was clinically acceptable. However, there was no significant increase in surface roughness for both polished and glazed types of used ceramics.