Effect of home and over the contour bleaching on stainability of CAD/CAM esthetic restorative materials.

Objective: To determine the effect of home and over the counter bleaching on the stainability of CAD/CAM restorative materials, and to correlate the surface roughness with discoloration.

Material And Methods: Specimens were fabricated from feldspathic ceramic, an hybrid ceramic, a resin nano-ceramic, and lithium disilicate-reinforced glass ceramic. After baseline surface roughness (Ra1) and color measurement, each material was randomly divided into three groups according to bleaching regimen as Opalescence PF and; Opalescence Go; control. Then, the second color and surface roughness (Ra2) measurements were made. Thereafter, all specimens were immersed in a coffee solution for 12 days and the third color measurement was made. Color and whiteness change (CIELAB- ΔE , CIEDE2000-ΔE , whiteness index-ΔWI ) were calculated after bleaching (ΔE1;ΔE 1;ΔWI 1) and immersion in the coffee solution (ΔE2;ΔE 2;ΔWI 2).

Results: According to both CIELAB, CIEDE 2000 and WI formulas, the highest mean ΔE1, ΔE2, ΔWI 1, ΔWI 2 values were observed for LAVA Ultimate groups while the lowest values were measured for e.max CAD groups. The findings also showed that there was a positively significant relationship between Ra2, and ΔE2 and ΔWI 2.

Conclusions: Type of restorative materials and bleaching agents had an impact on color change after bleaching and immersion in coffee.

Clinical Significance: Home and over-the-counter bleaching agents may cause an increase in susceptibility of restorative materials to staining.