Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 20 2 2026 06 30 Effect of different surface treatments of CAD/CAM zirconia core on the final color of porcelain veneered restorations 133 139 10.34172/joddd.44821 EN Ali Barzegar https://orcid.org/0000-0003-2591-3538 Mehrnaz Motiei https://orcid.org/0000-0002-2094-0732 Tahereh Ghaffari Peyman Irankhah Journal Article 10.34172/joddd.44821 2026 05 16 2026 07 26 Introduction: Achieving accurate color matching is essential for the aesthetic success of zirconia-based restorations, especially in the anterior region. Surface treatments are commonly used to enhance the bond between zirconia and porcelain, but their impact on the final color perception remains unclear. This study evaluated the effects of three surface treatments (control, acid etching, and sandblasting) on the color characteristics of zirconia veneered with porcelain. Methods: Sixty zirconia samples were divided into three groups: no surface treatment (control), acid etching, and sandblasting. Color measurements were taken using the CIE Lab* color system, with a specific focus on the color difference (ΔE) and the individual components of lightness (L), the red-green axis (a), and the yellow-blue axis (b). Results: The results showed that sandblasting resulted in the highest ΔE value (1.84±0.27), significantly greater than both the control (ΔE=0.77±0.43) and acid etching (ΔE=0.67±0.22) groups (P<0.05). Additionally, the sandblasted group exhibited a significant decrease in lightness (L=76.12), while the control group had a higher L value (L=77.85). No significant difference was observed between the acid-etched and control groups for any color component (P>0.05). Conclusion: Sandblasting significantly altered the optical properties of zirconia, leading to noticeable changes in color, particularly in lightness. In contrast, acid etching had minimal impact on color changes. These findings have clinical implications for the aesthetic planning of zirconia-based restorations, particularly in the anterior region, as highly aesthetic areas, where precise color matching is crucial.