Purpose: The current study aimed to investigate the effect of substrate and resin
cement shades on the optical properties of two ceramic laminate veneer materials.
Materials and Methods: Sixty four thin slices of ceramics were made from the two
materials (IPS e.max CAD, Vita Suprinity).They were divided into two equal groups
(n=32). Each group was subdivided into two subgroups (n=16) regarding to substrate
shade (A3,C4)on which each ceramic slice was cemented. Each Subgroup was further
subdivided into 2 divisions (n=8) according to resin cement shade (A1,WO). Color
measurement was done after cementation by using reflective spectrophotometer then
thermal aging process was done for 5000 cycles.(ΔE) values from a reference color (A1
shade) was calculated.Results: By comparing ceramic types vita suprinity recorded
statistically significant lower mean (ΔE) values than IPS e.max CAD.By comparing
resin cement shade on (ΔE) ,white opaque cement recorded statistically significant
lower mean (ΔE) value than A1 cement. As regards the effect of substrate,C4 composite
recorded statistically significant higher mean(ΔE)value than A3 composite. Finally
thermal aging effect on (ΔE),color change mean values after aging was statistically
non-significant higher than that before aging. Conclusion: The mean color change
(ΔE) was clinically acceptable for Vita Suprinity group than E.max CAD group, vita
suprinity ceramic can mask dark substrate more than E.max CAD and white opaque
cement shade also give better masking effect of dark substrate. After thermo cycling
color change was statistically non-significant higher than that before aging.