Influence of surface sealant on roughness and color of composites

Objectives: The purpose of this study was to evaluate the influence of surface sealant on surface roughness and color of the composite resins.

Methods: Microfilled (Metafil CX, Japan) and hybrid composite resin (Aelite™ LS posterior, USA) were used. Sixty specimens (8 mm diameter, 4 mm height) were made for each composite resin type, and they were divided into 3 groups. Each groups were grinded with 600, 1000, and 2000 grit sand paper. Specimens of each groups were applied with surface sealants, BisCover™ LV (Bisco, USA), Optiguard® (Kerr, USA), Seal-n-Shine™ (Pulpdent, USA), as instructed. CIE L*a*b* value of each specimen was measured with spectrophotometer (NF999, Nippon Denshoku Inc. Co., Japan) and surface roughness (Ra) of each specimen was measured with surface roughness tester (SJ-301, Mytutoyo, Tokyo, Japan) before and after surface sealant was applied. The color difference (ÄE*) was calculated before and after application of surface sealants. Specimens were observed by scanning electron microscope (SEM, JSM-7500, JEOL, Japan) and atomic force microscope (AFM, MultiMode IV, Veeco Instruments, USA).

Results: Specimens which were grinded with 600 grit sand paper, and then surface sealant was applied exhibited significantly lower Ra value (p<0.05). Hybrid composite resin manifested higher color difference (DE*) than microfilled composite resin after surface sealant was applied. There was no significant difference in color difference and surface roughness among BisCover™ LV, Optiguard®, and Seal-n-Shine™. After surface sealant was applied, remarkably decreased micro-defect on the surface of composite resin was observed through SEM and AFM.

Conclusions: Surface sealant can influence surface roughness and color when applied on rough surface of composite resin, but not highly polished composite resin.