Effect of surface treatments on staining and roughness of bleached enamel

Background: The objectives were to evaluate the effect of surface treatments and waiting time before contact with dye on bleached enamel staining and surface treatments on roughness.

Methods: One hundred bleached teeth were randomly assigned to G1 artificial saliva, G2 2% sodium fluoride (Flugel, Nova DFL), G3 casein phosphopeptide-amorphous calcium phosphate fluoride paste (MI Paste Plus, GC America), G4 rinse for bleached color maintenance (Keep White Rinse, DMC), and G5 polishing with impregnated disks (SuperBuff Disk, Shofu). Fifty specimens were immersed in coffee immediately after treatment; the others 1 h after. Color difference (ΔE) was evaluated with a spectrophotometer (Vita EasyShade) and roughness (Ra, Rq) with an optical profilometer (NewView 7300). Effects were analyzed with two-way ANOVA, Friedman, and Kruskal-Wallis test (P < 0.05).

Results: Surface treatments (P = 0.878), waiting time (P = 0.105), and interaction (P = 0.145) were not significant to bleached color maintenance. Roughness was different among the evaluation time points (2^nd evaluation >1^st evaluation >3^rd evaluation) (P < 0.001); not among surface treatments (G1, G2, G3, G4, G5) (P > 0.05).

Conclusions: Surface treatments were similar to saliva for bleached enamel color maintenance. Immediate or 1-h postponed contact with coffee did not affect bleached enamel color. Bleaching increased enamel roughness; surface treatments and artificial saliva decreased it.