Effect of daily immersion of different beverages on the surface roughness and color stability of 3D-printed denture base resins.

Abstract

Purpose: To measure the effect of daily immersion in varying beverages (distilled water, tea, carbonated beverage, and orange juice) on surface roughness and color stability of 3D-printed denture base resins.

Materials and methods: 160 acrylic resin discs (15 × 2.5 mm) were made from heat-polymerized (HP), and 3D-printed resins (FormLabs, ASIGA, and NextDent). Resin discs (N = 40) were immersed in different solutions (distilled water, tea, carbonated beverage, or orange juice; (n = 10/group)). Surface roughness (R_a, µm) was measured initially (T₀), 6 months post immersion (T₁), and 12 months post immersion (T₂) using a non-contact profilometer. Color change (∆E₀₀) was calculated using CIEL2000 at T₁ and T₂ using a spectrophotometer. The data were analyzed using Mann-Whitney U test and Kruskal-Wallis test in addition to general linear modeling (α = 0.05).

Results: Significant differences in surface roughness (R_a) were found between the baseline and immersion in distilled water, carbonated beverage, and orange juice (p < 0.05). HP resin showed increased roughness with all immersion solutions compared to T₀ with the highest value seen at T₁ with tea. ASIGA resin had the highest mean R_a of 1.78 (0.43) after carbonated beverage immersion, while FormLabs resin had the lowest mean R_a of 0.88 (0.06) after distilled water immersion. Tea immersion did not significantly affect R_a among the resins (p > 0.05). Noticeable color changes were observed after immersion in tea, carbonated beverage, and orange juice. All resins exceeded perceptibility and acceptability thresholds at T₁ and T₂. The combined effect of time and resin on color change was statistically significant (p < 0.001), while the combined effects of time/immersion solution, immersion solution/resin, and immersion solution/resin/time were not.

Conclusion: Carbonated beverage, tea, and orange juice increase the surface roughness of 3D-printed resins. Tea, carbonated beverage, and orange juice resulted in noticeable color changes of HP and 3D-printed denture base resins and this change was time-dependent.