摘要：

Objectives: Many protective resin coatings have been developed for sealing marginal gaps and giving a lustrous appearance to composite restorations. The aim of this study was to evaluate the abrasion resistance, surface roughness and gloss of a new generation of composite surface sealers (CSS). The testing hypothesis was that significant differences exist among products tested. Methods: The CSS tested were Biscover LV (BC), DuraFinish (DF), G-Coat Plus (GC) and PermaSeal (PS). Composite specimens (7mmx3mmx2mm, n=4), were coated with the CSS and irradiated with a halogen curing unit (20s, 750mW/cm2). Optical microscopy and glossimetry were used to evaluate changes before and after a toothbrush abrasion test (25K cycles). PS and GC representing dimethacrylate and monomethacrylate compositions were further evaluated by quantitative optical profilometry to evaluate Sa and volume loss. ANOVA and Tukey tests were used to statistically evaluate mean differences among products tested. A t-test was used for comparison of the profilometric data (α=0.05). Results: All products resulted in a significant gloss reduction after toothbrush wear. BC and PS presented the highest gloss reduction (ΔG)(29.4±2.7 and 32.8±5,3 respectively), although their gloss values were still higher than DF (24.4±12.0) and GC (25.1±12.6). Optical microscopy revealed less surface defects in PS and BC than in DF and GC. Optical profilometry showed significantly increased Sa (0.90±0.20 vs 0.60±0.14) and similar material volume loss in GC (0.10±0.01 vs 0.11±0.01) in comparison with PS. Conclusions: Although BC and PS presented the highest ΔG, they still remained glossier than DF and GC after toothbrush abrasion. GC presented a rougher surface and similar material loss to PS.

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