Statement of problemNo information is available on roughness and stainability of acrylic resins polymerized by experimental microwave cycles after immersion in stainable liquids and simulated brushing. PurposeThe purpose of this in vitro study was to evaluate the effect of stainable drinks and brushing on roughness and stainability of acrylic resins (Vipi Cril [CA] and Vipi Wave [MA]) polymerized with different cycles. Material and methodsCA and MA specimens (n=5; diameter, 20 mm; thickness, 3 mm) were made using 4 methods recommended by the manufacturer (water bath polymerization and microwave polymerization cycles) and experimental at 550 W or 650 W for 3 or 5 minutes (M550/3 and M650/5), respectively. After storage in distilled water at 37°C for 48 hours (T0), the specimens were stored in water, coffee, or red wine (37°C) for 36 days with simulated brushing (54 000 cycles, T1). Roughness (Ra) and stainability (ΔE/National Bureau of Standards) were measured at T0 and T1. Roughness and stainability data were analyzed by 3-way repeated measures and 2-way ANOVA, respectively, followed by the Bonferroni test (α=.05). ResultsAfter storing in coffee and brushing, CA showed the highest (M550/3=2.33 ±0.72 μm) and the lowest roughness (water bath polymerization=1.22 ±0.58 μm), whereas roughness of MA specimens processed by M650/5 increased (1.57 ±0.59 μm). Storing in wine and brushing increased roughness (1.75 ±0.32 μm) in the M550/3 group. No staining was observed on MA after brushing regardless of the polymerization cycle. All values were acceptable (ΔE≤3.3), except for MA (microwave polymerization), which showed National Bureau of Standards=4.49 (appreciable change) after storing in wine and brushing. ConclusionsA slight increase in material roughness was observed after staining and brushing. Only MA polymerized following manufacturer cycles showed relevant stainability after immersion in wine and brushing.