RESUMO
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.
