Background: Ultra-Opaque resin cement is a promising material introduced in the market aiming to masking discolored substrates such as tooth, titanium implants and metallic posts. Aim: To evaluate the masking ability of the ultra-opaque resin cement to different discolored substrates. Material and Methods: Sixty disk shaped ceramic specimens (10mm X 1mm) fabricated from three ceramic materials (N=20) cemented to sixty Ni-Cr metal discs and were divided into three groups according to the type of ceramic material; Lithium disilicate ceramic (IPS e.max CAD), zirconia reinforced lithium disilicate (vita suprinity), and Ultra-translucent zirconia (katana zirconia). Each group was subdivided into two equal subgroups according to the type of the resin cement: Breeze Resin Cement (Self-adhesive Resin Cement) and vita adiva IA-CEM (Ultra-opaque implant abutment composite). Color measurements of the three groups were assessed before and after cementation using Spectrophotometer based on CIE L*a*b* relative to the standard illumination D65. Color difference was obtained by calculating the difference in color measurements using the formula ∆E=[(∆L*)2 +(∆a*)2 +(∆b*)2] ½. Results: After thermocycling, ultra-opaque cement showed lower mean ∆E compared to conventional resin cement. Conventional resin cement showed lower mean ∆E than ultra-opaque one with Katana group, while there was no statistically significant difference among other groups. Conclusions: whatever type of ceramic used; the ultra-opaque resin cement has higher masking ability than conventional resin cement.