effects of wet and dry finishing and polishing on surface roughness and microhardness of composite resins

Objectives: this study aimed to assess the effect of wet and dry finishing and polishing on microhardness and roughness of microhybrid and nanohybrid composites. materials and methods: thirty samples were fabricated of each of the polofil supra and aelite aesthetic all-purpose body microhybrid and grandio and aelite aesthetic enamel nanohybrid composite resins. each group (n=30) was divided into three subgroups of d, w and c (n=10). finishing and polishing were performed dry in group d and under water coolant in group w. group c served as the control group and did not receive finishing and polishing. surface roughness of samples was measured by a profilometer and their hardness was measured by a vickers hardness tester. data were analyzed using two-way anova (p<0.05). results: the smoothest surfaces with the lowest microhardness were obtained under mylar strip without finishing/polishing for all composites (p<0.0001). the highest surface roughness was recorded for dry finishing/polishing for all composites (p<0.0001). dry finishing/polishing increased the microhardness of all composites (p<0.0001). conclusions: dry finishing and polishing increases the microhardness and surface roughness of microhybrid and nanohybrid composite resins.