The effect of different surface treatments on the color change of CAD/CAM restorative materials caused by coffee

Meryem  Erdoğdu; Gözde  Kaya Oğuz; Merve Karagöz; Ali Rıza  Tunçdemir; Emine Begüm Büyükerkmen

doi:10.5577/intdentres.670

Open Access Original Article

Meryem Erdoğdu⁽¹⁾, Gözde Kaya Oğuz⁽²⁾, Merve Karagöz⁽³⁾, Ali Rıza Tunçdemir⁽⁴⁾, Emine Begüm Büyükerkmen⁽⁵⁾

(1) Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye,

(2) Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye,

(3) Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye,

(4) Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye,

(5) Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye

https://doi.org/10.5577/intdentres.670

Issue
Vol. 15 No. 3 (2025): International Dental Research

Submitted
25 October 2025

Accepted
1 December 2025

Published
31 December 2025

Keywords:

CAD-CAM, color stability, dental polishing, composite resin, coffee, surface properties

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Abstract

Aim: This study aimed to evaluate the effect of different surface treatment protocols on the color stability of two CAD/CAM restorative materials, a hybrid ceramic (Vita Enamic) and a resin-based composite (Shofu Block HC), when exposed to filter coffee.

Methodology: Sixty disk-shaped specimens (12 mm diameter, 1.5 mm thickness) were prepared from Vita Enamic and Shofu Block HC. The specimens were divided into six groups (n=10) based on the material and surface treatment: Mechanical Polishing Only, Glaze (Optiglaze) Only, and Mechanical Polishing + Glaze. After the surface treatments, baseline color measurements were performed using a spectrophotometer (Vita EasyShade V). The specimens were then immersed in a freshly prepared filter coffee solution, which was renewed daily for 15 days (simulating ~3 years of clinical exposure). Post-immersion color measurements were taken, and the color difference (ΔE) and lightness difference (ΔL) were calculated. Data were analyzed using two-way ANOVA and Tukey's HSD test (p < 0.05).

Results: Two-way ANOVA revealed significant main effects of Material and Surface Treatment on both ΔE and ΔL (p < 0.001). A significant Material × Surface Treatment interaction was found for ΔL (p = 0.012) but not for ΔE (p = 0.207). Vita Enamic demonstrated significantly lower ΔE and higher ΔL values than Shofu Block HC, indicating better overall color stability and less darkening. For both materials, Mechanical Polishing Only resulted in significantly lower ΔE than glaze only or the combination group. For ΔL, Mechanical Polishing was superior for Vita Enamic, whereas Glaze Only yielded the most unfavorable results for Shofu Block HC.

Conclusion: The color stability of CAD/CAM materials is significantly influenced by both material composition and surface treatment applied. Mechanical polishing provided the best color stability for both materials tested. Clinically, for restorations prone to coffee exposure, selecting a hybrid ceramic like Vita Enamic and finishing it with mechanical polishing is recommended to optimize long-term aesthetic performance.