Method: The following 4 types of composite resin were used: Estelite sigma Quick(EST:Tokuyama Dental Corp.); Prime Fil Flow (PFF:Tokuyama Dental Corp.) Mi Fil (MIF:GC Corp.); and Mi Low Flow (MIL:GC Corp.). Their upper and lower surface were irradiated for 80 seconds, for a total of 160 seconds, in a metal mold of 15 mm in diameter and 2 mm in height, using Curring Light XL3000 (3M CO.). Subsequently, they were polished for 10 seconds, using an automatic rotary polisher with 5 types of waterproof of carbide paper with different levels of roughness, and dried to evaluate their gloss levels with the measurement device VG2000 (Nippon Denshoku Industries CO.,Ltd). Measurement was repeated 5 times at 3 points in each sample, and their means were adopted to perform a 2-way factorial analysis of variance.
Result: Gloss levels increased with a decrease in the level of roughness of carbide papers in all samples. PFF and MIF showed the highest and lowest gloss levels, respectively, in all polishing processes. The gloss level was highest, 60.8%, when polishing PFF with carbide paper #1500. On comparison between conventional and flowable composite resins, the latter showed significantly higher gloss levels.
Conclusion: These results suggest that gloss levels may vary among different types of composite resins; while they increased with a decrease in the level of roughness of carbide papers, and were higher in the flowable compared to conventional type. In order to increase gloss levels of composite resins in clinical environments, it may be effective to polish them, while gradually reducing the roughness of carbide papers.