Detrimental effects exerted on oral and dental tissues by frequent mouthrinse use are observed, but studies about their effects on aesthetic restorative materials are limited. In this study, the purpose was to examine the effects of three proprietary mouthrinses on three different aesthetic restorative materials. Mouthrinses were used as treatment groups, while distilled water served as the control. From a total of 72 specimens, each experimental group consisting of 24 samples were prepared from each restorative test material by using metal moulds. The samples were stored in 20 mL of one of the mouthrinses for 12 h, which was reported as the equivalent time to 1 year of 2-min daily mouthrinse use. Changes between baseline and after treatment measurements of surface microhardness and colour of the test materials were established by using Vickers microhardness tester and spectrophotometer. Statistical analyses were performed by analysis of variance (anova), with Bonferroni correction. The level of significance was set as 0.05 in all tests. There were no significant interactions between the test solutions and the test materials with regard to microhardness (P > 0.05), and colour changes of the materials (P > 0.05). Effects of mouthrinses on restorative materials may differ depending on many in vivo factors that could not be replicated in vitro. Therefore, routine assessment of the effects of mouthrinses on aesthetic restorative materials is recommended.