effect of an alcohol containing-mouthwash on the surface roughness of a nanohybrid composite resin

Objective: this study aimed to compare the surface roughness of a nanohybrid composite resin after immersion in an alcohol-containing mouthwash and a non-alcoholic mouthwash.methods: twenty-seven cylindrical nanohybrid composite resin samples were prepared and immersed in distilled water in an incubator for 24 hours, then divided into three groups. the samples in group 1 were immersed in an alcohol-containing mouthwash (listerine® zero with 21.6% alcohol), while those in group 2 were immersed in a non-alcoholic mouthwash (listerine® zero). group 3 samples were immersed in a saline solution as the control. the samples were subjected to 12 cycles of 1-minute immersion in the respective solution per day. between the cycles, samples were kept in distilled water at 37°c. the procedure was repeated for 30 days, totalling 360 cycles. the average surface roughness (ra) of the composite samples was measured using a stylus-based surface roughness tester after the immersion cycles.results: anova revealed a significant difference in surface roughness among the study groups (p = 0.011). tukey test showed that the alcohol-containing mouthwash caused significantly greater roughness in the nanohybrid composite resin compared to the non-alcoholic mouthwash and saline solution (p<0.05).conclusions: the surface roughness of nanohybrid composite resin was significantly increased after exposure to the alcohol-containing mouthwash compared to the non-alcoholic mouthwash and saline. this increased roughness can potentially compromise the clinical performance of esthetic restorative materials by promoting surface degradation and reducing wear resistance, and should be considered in clinical practice.