Effects of Surface Finishing Procedures on the Color Stability of Resin-Matrix Ceramics: An In Vitro Study

Resin-matrix ceramics are among the increasingly preferred dental biomaterials in restorative dentistry. However, these materials are continuously exposed to staining from beverages in the oral environment, and continue to present limitations in terms of long-term aesthetic performance. This study was designed to evaluate the effects of different surface finishing procedures and immersion in commonly consumed beverages on the color change (ΔE00) of four different resin-matrix ceramics (Cerasmart, Lava Ultimate, Shofu Block HC, and Vita Enamic). A total of 256 specimens were randomly assigned to mechanical polishing or glazing, then immersed in coffee, red wine, cola, or distilled water for 14 days. Data were analyzed using three-way repeated-measures analysis of variance (ANOVA), with Tukey and Bonferroni post hoc tests (α = 0.05). Surface finishing procedure, material type, beverage type and immersion time significantly affected ΔE00 values (p < 0.05). The highest ΔE00 values were observed at 14 days in the red wine-immersed glaze groups of Shofu Block HC (ΔE00 = 7.44 ± 0.45) and Lava Ultimate (ΔE00 = 7.24 ± 0.83). These findings suggest that surface finishing procedures and material selection play a critical role in preserving the aesthetic performance of resin-matrix ceramic restorations, and mechanical polishing may be considered a clinically favorable approach for computer-aided design and computer-aided manufacturing (CAD/CAM) restorations.