Effect of Different Surface Treatments of CAD/CAM Zirconia Core on the Final Color of Porcelain-Veneered Restorations.

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 porcelain-veneered zirconia.

METHODS

Sixty zirconia samples were divided into three groups: no surface treatment (control), acid etching, and sandblasting. Color measurements were taken using the CIELab* 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 those of 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.