Effect of Food Simulating Solvents on Surface Roughness and Microhardness of Bulk Fill Resin Composites.

Objectives: To evaluate the effect of food simulating solvents on surface roughness and microhardness of bulk fill resin composites in-vitro. Materials and methods: A total of 180 discs were made with (Filtek One bulk fill, REVEAL HD and x-tra fil bulk fill (n=60). The baseline data of surface roughness and microhardness measurements were recorded. Each group was divided into three subgroups, subgroup1 was immersed into methyl ethyl ketone (n=20), subgroup2 was immersed into ethanol (n=20) and, subgroup3 was immersed into artificial saliva (n=20) as control group. After 30 days, half of each subgroup was tested for surface roughness (n=10) by surface profilometer and the other half was tested for microhardeness (n=10) by Vicker’s microhardness tester. The collected data were statistically analyzed using one-way analysis of variance (ANOVA) then Tukey’s post hoc test for pairwise comparison (p ≤0.05). Results: All tested materials showed significant differences in surface roughness and microhardness. x-tra fil composite group had the most statistically significant increasing in surface roughness and the most significant decreasing in microhardness was in Filtek One Bulk. Methyl ethyl ketone caused the most surface changes in bulk fill resin composites. Conclusions: Bulk fill resin composites significantly increased in surface roughness and decreased in surface microhardness after Immersion in food simulating solvents.