Bioactive Resin Cement Color Stability and Restoration Thickness as Determinants of the Final Shade in a...

Bioactive resin cements are gaining popularity for their clinical benefits, but concerns remain regarding their color stability. This study evaluated the color change (ΔE₀₀) and whiteness change (ΔWI_D) in bioactive resin cements and how their potential discoloration affects the shade of bonded CAD/CAM glass-ceramics at different ceramic thicknesses. VITA Mark II blocks were prepared in three thicknesses (0.5, 0.8, and 1.0 mm) and divided by resin cement: Panavia SA Universal (Pn), Predicta Bioactive Cement (Pr), and ACTIVA BioACTIVE Cement (Ac) (n = 10). Additionally, 10 specimens (10 × 2 mm) of each cement alone were prepared. Color was measured before and after 24 days of coffee immersion. Cement type significantly affected ΔE₀₀ (p < 0.001). Pn had the highest color stability, followed by Pr and Ac, with significant differences between each. ΔWI_D also varied by cement (p = 0.004), with Pn and Pr differing significantly from Ac. Ceramic thickness alone had no significant effect on ΔE₀₀ or ΔWI_D, but its interaction with cement type was significant (p < 0.001). While ceramic thickness does not directly affect the final shade, its combination with resin cement does. Choosing the right resin cement is key for long-term esthetic outcomes.