The effect of commonly used polishing protocols on the color stability of 3D- printed temporary crowns

OBJECTIVE: Color stability is a crucial parameter for maintaining the long-term esthetic success of temporary restorations. This study aimed to evaluate the effects of different clinical polishing protocols applied to three-dimensional (3D) printed temporary resin crowns on their color stability. MATERIALS-METHODS: Fifty standardized specimens (12×12×2 mm) were prepared using a 3D printing resin material (PowerResins, Temp Resin, A2, Turkiye) and randomly divided into five groups (n=10) as G1: Control (no polishing), G2: Mechanical polishing (DCPT 14 RA SET), G3: Silicon dioxide containing polishing paste (Promida Prophy P), G4: Mechanical + silicon dioxide paste, G5: Diamond particle-containing polishing paste (Intensiv Unigloss). Initial color measurements were performed using a digital spectrophotometer (Vita Easyshade V). TSpecimens were exposed to a daily coffee cycle for 15 days. Color differences were calculated using the CIEDE2000 (ΔE00) formula, and the data were analyzed by one way analysis of variance (ANOVA). Tukey’s post-hoc test was applied for multiple comparisons (p < 0.05). RESULTS: No significant differences were observed between the groups before the coffee staining cycle (p > 0.05). After staining, intergroup differences were statistically significant (p < 0.05). The lowest ΔE00 values were recorded in G5 (diamond particle- containing polish). G3 and G4 exhibited moderate color changes, comparable to the control group (G1). The highest color change was observed in G2 (mechanical polishing only), with ΔE00 values exceeding the clinically perceptible threshold (ΔE00 ≥ 0.8). CONCLUSION: The diamond particle-containing polishing paste provided the best color stability both statistically and clinically. The polishing protocol plays a decisive role in the color stability of 3D-printed temporary crowns. The use of diamond-containing polishing systems is recommended, particularly in esthetic zone restorations.