Effect of Food Simulating Liquids and Simulated tooth Brushing on Surface Roughness of Different Resin Composite Materials

Aim: The study aimed to evaluate the effect of food simulating liquids with or without ‎simulated tooth brushing on surface roughness of different resin composite materials.‎ Materials and Methods: Three resin composite materials (Palfique LX5, Neo Spectra ST and ‎Brilliant Ever Glow) were used in the study. A total of 180 specimens were prepared, 60 ‎specimens of each composite material. Each main group was divided into three subgroups ‎‎(n=20) according to the three food simulating liquids (FSL) used (distilled water, methyl ethyl ‎ketone, and 0.02 M citric acid). The specimens were immersed in each FSL for 15 days. ‎Specimens were further subdivided into 2 groups (no brushing and simulated brushing) (n=10). ‎Simulated tooth brushing was done in an automatic toothbrushing machine. Surface roughness ‎was measured and data were collected, tabulated and statistically analyzed. ‎ Results: Surface roughness of the three tested composite resin materials without brushing ‎showed no statistically significant difference at p≤0.05 after storage in both distilled water and ‎citric acid. MEK significantly increased the surface roughness of Brilliant everglow. After ‎simulated tooth brushing; Neospectra recorded the highest surface roughness value in citric ‎acid and distilled water. While, Brilliant everglow recorded the lowest surface roughness in ‎citric acid and distilled water. MEK significantly increased the surface roughness of Neospectra ‎and decreased that of Brilliant everglow.‎ Conclusion: The food simulating solutions and simulated tooth brushing altered the surface ‎roughness of tested resin composites and these alterations are material dependent. Repolishing ‎is recommended once per year for Neospectra and Palfique.