Effect of Different Bleaching Methods on Color Stability of Two Laminate Veneer Materials

Objective: This study evaluated the effect of different bleaching methods on the color stability of different laminate veneer materials. Materials and methods: Twenty samples were divided into two main groups; 10 discs of lithium disilicate glass-ceramic (IPS E Max CAD) representing group E and 10 discs of nanoceramic composite representing group C. Each main group was divided into two subgroups (n=5) where subgroup (O): received chemical in-office bleaching, and subgroup (L): received Diode laser-activated bleaching. Color measurement of each group was assessed at baseline, after their accelerated coffee staining for one week, and finally after bleaching agent application. The color of the samples was evaluated according to the CIE L*C*H color parameters using a Vita Easy-Shade Spectrophotometer. Colors were compared using the ∆H*, ∆C*, ∆L*, and ∆E at baseline, after accelerated coffee staining, and after bleaching.Results: There were statistically significant differences among study groups for all color parameters after accelerated staining with coffee. After bleaching, there were statistically significant differences among study groups for all color parameters, the lowest mean color change value of ∆E was revealed by the IPS E Max CAD samples treated with in-office bleaching (EL), followed by EO, then CL, and the greatest mean color change value was revealed by CO.Conclusions: IPS E Max CAD ceramic can provide the best choice for a color-stable veneer that can preserve its color even after Diode laser-activated bleaching.