Effect of Surface Sealants and Polishing Time on Composite Surface Roughness and Microhardness.

The objective of this study was to evaluate the effect of surface sealants and polishing delay time on a nanohybrid resin composite roughness and microhardness. Eighty disc specimens were made with a nanohybrid resin (Esthet-X HD, Dentsply). The specimens were divided into two groups (n=40) according to polishing time: immediate, after 10 minutes; delayed, after 48 hours. Each group was subdivided into four groups (n=10), according to the surface treatment: CG, control-rubber points (Jiffy Polishers, Ultradent); PP, rubber points + surface sealant (PermaSeal, Ultradent); PF, rubber points + surface sealant (Fortify, Bisco); PB, rubber points + surface sealant (BisCover, Bisco). Surface roughness (Ra) and microhardness (50 g/15 seconds) were measured. Surface morphology was analyzed by scanning electron microscopy and atomic force microscopy. The data were analyzed statistically using one-way analysis of variance and the Games-Howell post hoc test (α=0.05). PermaSeal roughness (G2) in the delayed polishing group was significantly higher ( p=0.00) than that of the other groups. No difference was observed among the groups between immediate and delayed polishing ( p=1.00), except for PermaSeal ( p=0.00). Moreover, PermaSeal showed the lowest microhardness values ( p=0.00) for immediate polishing. Microhardness was higher at delayed polishing for all the surface treatments ( p=0.00) except Fortify ( p=0.73). Surface smoothness similar to polishing with rubber points was achieved when surface sealants were used, except for PermaSeal surface sealant, which resulted in a less smooth resin composite surface. However, surface sealant application did not significantly improve composite resin microhardness.