The effect of mouthrinses on salivary sorption, solubility and surface degradation of a nanofilled and a hybrid resin composite.

This in vitro study evaluated the effect of mouth rinses on salivary sorption (Sp), solubility (Sl) and surface degradation of a nanofilled (Z350) and hybrid (P60) resin composite. Specimens (6 mm in diameter and 1 mm thick) of a nanofilled and hybrid resin composite were immersed in artificial saliva at 37 degrees C for seven days. Twice a day, the samples (n = 5) were immersed in 20 ml of three mouth rinses: Listerine, Plax Mint and Plax. A control group was maintained in artificial saliva. Sp and Sl were evaluated based on ISO 4049:2000(E) and surface degradation by scanning electron microscopy-SEM. The degree of conversion (DC%) of resin composites was obtained by using an FT-IR spectrometer equipped with an attenuated total reflectance crystal (ATR). The data were analyzed using the Student's t-test, ANOVA and Tukey test for multiple comparisons. No significant difference in DC% was found between the two resin composites (p < 0.05). The highest sorption rate was presented by the nanofilled composite exposed to Listerine (p < 0.05). The hybrid composite in the control group (artificial saliva) and Plax presented the lowest sorption (p < 0.05). The highest solubility was presented by the two resin composites exposed to Listerine (p < 0.05). SEM analysis showed that mouth rinses produced more severe surface degradation in the nanofilled composite.