Effect of various beverages on the surface roughness and color stability of different denture base resins: An in vitro study

Background. Denture base materials can be highly sensitive to the effects of daily beverage consumption, manifesting in alterations to their surface texture or color. Objectives. The study aimed to evaluate the effect of different beverages (Pepsi, coffee and tea) on the surface roughness (Ra) and color stability of 3 types of denture base materials. Material and methods. A total of 120 specimens (n = 10/group) were fabricated from 3 different denture base materials, namely heat-polymerized polymethyl methacrylate (HP), thermoformed polyamide (PA) and acetal (AC). The surface roughness and color stability of the specimens were evaluated 3 times: before immersion in beverages; after 30 days of immersion; and after 90 days of immersion in artificial saliva (a control group) and Pepsi, coffee and tea (test groups). The data analysis was performed using two-way analysis of variance (ANOVA) to compare the results of Ra and color change (ΔE) between denture base resins and beverages. Results. The differences between the materials, beverages and time were significant for Ra values, as well as the interaction between materials and beverages, and between beverages and time. The findings indicated significant differences in ΔE between denture base materials. In comparison to PA and AC, HP exhibited lower ΔE values. A significant change in color was observed over time for all of the tested materials. Conclusions. The tested beverages increased Ra and caused change in the color stability for all materials. The observed color change was correlated with the duration of the immersion, and was more evident in thermoformed resins.