Abstract
BACKGROUND: This study evaluated the color stability of digitally fabricated complete dentures compared to conventional ones. MATERIALS AND METHODS: Forty-five specimens were fabricated using 3 different manufacturing methods (injection mold, one-piece milling, and two-piece 3D printing and milling techniques), with 15 specimens per group. After implementing a standardized polishing protocol, each group was randomly subdivided into three subgroups (n = 5) and immersed in distilled water, coffee, and red wine for seven days at a controlled temperature of 37 °C. Color changes in denture teeth and base materials were evaluated utilizing VITA Easyshade and ImageJ software before and after immersion. Subsequently, all specimens underwent a manufacturer-recommended denture cleansing regimen for seven days, followed by a repeated staining cycle. Two-way ANOVA and Tukey post-hoc tests were used for statistical analysis (α = 0.05), while the prevalence of denture tooth shade change was reported descriptively. RESULTS: The finding revealed that coffee caused more discoloration than red wine. Milled specimens showed better color stability against red wine than conventionally fabricated dentures. While initial staining was noted, the cleaning protocol successfully restored the original colors. This pattern persisted with repeated staining, highlighting the importance of material selection and maintenance in maintaining denture aesthetics. CONCLUSIONS: Exposure to coffee and red wine leads to noticeable color changes in both denture teeth and base materials. The degree of staining depends on the specific material composition, highlighting the importance of selecting stain-resistant materials for better long-term color stability. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12903-025-07197-3.