Effect of mouth rinses on the hardness of three tooth-colored restorative materials
Tooth-colored restorative materials, such as composite resins, glass-ionomer cements or compomers are routinely used for tooth restoration. Alcohol is used in mouth rinses as a solvent, taste enhancer and an antiseptic agent but studies have shown it to be directly related to softening of composite resin restorations.
The aim of this study was to evaluate changes in the hardness of glass-ionomer cement, compomer and composite resin when exposed to six varieties of mouth rinses at intervals of 1 h, 1 day, 7 days and 14 days.
Materials and methods The tooth-colored restorative materials investigated in this study were ChemFlex (MI), EsthetX (M2) and Dyract (M3). A total of 147 specimens were prepared, 49 from each restorative material. Over a period of 14 days the samples were immersed twice daily for 2 min in 15 ml of the respective mouth rinse. After each immersion, the specimens were washed and stored in artificial saliva. A Vickers hardness number (VHN) was obtained from the readings at 1 h, 1 day, 7 days and 14 days after the first immersion.
The average VHN values for each day for all materials were analyzed for significant differences using ANOVA and F-test to investigate the VHN differences between storage time and medium.
Mouth rinses significantly softened the hardness of restorative materials. The properties of composite resin were found to be affected more by the mouth rinses than that of compomer and glass-ionomer cement.
This study showed that the higher the content of alcohol in the mouth rinse the more adverse the effects on the hardness of restoratives.