Methods: Four universal resin composites; Clearfil Majesty ES-2 Classic (CM, Kuraray Noritake Dental), Estelite Σ Quick (EQ, Tokuyama Dental), Solare (SO, GC), Filtek Supreme Ultra (SU, 3M ESPE), and two flowable resin composites; Beautifil Flow F10 (BF, Shofu), MI Low Flow (MI, GC) and were used. The surface of resin-composite filled into a cylindrical mold (φ15x5mm) was pressed and flattened with a transparent film, and then cured with a light source (Optilux 501, Kerr). The flattened surface was polished with three polishing systems; Compomaster (COM, Shofu), Pre Shine + Dia Shine (DIA, GC) and Soflex XT (SOF, 3M ESPE) according to the manufacturer’s instructions. Surface gloss of polished surface and film flattened-unpolished surface (control) of every resin-composite were measured (n=6) using a gloss checker (IG-331, Horiba). The data were analyzed using two-way ANOVA and Tukey’s q-test.
Results: Mean surface gloss values of polished surfaces (37.7-72.7) of six resin-composites were significantly smaller than the values of control surface (83.4-95.9).Both factors of differences in resin-composite and polishing system influenced surface gloss significantly (p<0.01) and there was an interaction effect between two factors (p<0.01).The surface gloss of six resin-composites became smaller in the order, SU≥CM≥MI>BF≥EQ>SO, and the values of three polishing systems were DIA>COM>SOF.
Conclusion:The polished surfaces of six resin-composites used in this study were significantly inferior to the film pressed-unpolished surface(control) in surface gloss, and polishing effects with three systems were varied with the resin-composite restoratives.