In Vitro Evaluation of Resilient Liner after Brushing with Conventional and Experimental Ricinus communis‐Based Dentifrices

Purpose To evaluate the effect of experimental (Ricinus communis) and commercial dentifrices used for denture cleaning on abrasiveness (gravimetric method; roughness), hardness, and color stability of a resilient relining material. Materials and Methods Sixty circular (15 × 3 mm) specimens were distributed into four groups: C (control; brushing with water); CO (brushing with Colgate – for natural teeth); CB (brushing with Corega Brite – for complete dentures); RC (brushing with experimental dentifrice). Brushing was performed in a toothbrushing machine with a soft brush and a dentifrice suspension for 50 minutes, calculated to correspond to 1 year of regular brushing. Variables were measured initially and after the trial period. For the gravimetric method, the difference in mass was considered. The surface roughness was measured by a rugosimeter, and the hardness test was performed by a Shore A durometer. Color changes (ΔE; CIE L*a*b* and NBS systems) were measured by a portable spectrophotometer. Results were analyzed by ANOVA/Tukey's test (α = 0.05). Results The largest mass variation (μg; p < 0.0001) occurred in C (–6.21 ± 3.18). Concerning roughness, CB (0.26 ± 0.04) showed the lowest value, followed by RC (0.29 ± 0.08) and CO (0.34 ± 0.24) (p < 0.0001). Group C produced the greatest surface roughness (0.72 ± 0.25). Hardness values decreased after brushing with water (p = 0.014). No significant differences were found among RC (50.31 ± 1.03), CO (49.11 ± 1.31), CB (49.17 ± 1.23), and C (48.02 ± 1.26). Color stability was similar in all groups (p = 0.135; C: 2.3 ± 0.77; CO: 2.6 ± 0.54; CB: 2.2 ± 0.44; RC: 2.9 ± 1.56). Conclusions The use of experimental dentifrice could be indicated, as it showed similar results to the specific dentifrice, keeping the resilient material properties within acceptable values.