Alcohol-containing mouthwashes: effect on composite hardness.

This study evaluated the effects of alcohol-containing mouthwashes on composite resin hardness. Eighty hybrid composite discs were fabricated and divided into eight equal groups: Listerine, Scope, Viadent, Plax, Lavoris, Clear Choice, and Rembrandt Mouth Refreshing Rinse. Water acted as a control. All of the discs were immersed by group in their respective liquids for two minutes a day over a period of six months. Disc hardness was measured six times at the center and periphery using a Barcol impressor. The baseline values were taken for each disc and compared to the test values at the end of six months. The results of the study indicate that the alcohol content in mouthwashes can affect composite hardness. This softening affect can be directly related to the percentage of alcohol in the mouthwash.