Polishing techniques effect on microhybrid, nanohybrid and nanofilled composites color and surface roughness stability

Resumo

Resin roughness and staining is a common problem in dentistry. Objective: the aim of this study was to verify the influence of single and multiple-steps polishing techniques on color stability and surface roughness of differents composite resins. Groups were (n=10): FS+CS. Filtek Supreme XT + clear strip; FS+PG. Filtek Supreme XT+PoGo; FS+SF. Filtek Supreme XT+Sof-Lex; AM+CS. Amelogen+clear strip; AM+PG. Amelogen+PoGo; AM+SF. Amelogen+Sof-Lex; TEC+CL .TetricEvoCeram + clear strip; TEC+PG .Tetric EvoCeram+ PoGo; TEC+SF .Tetric EvoCeram+Sof-Lex; CED+CS .Ceram X Duo+clear strip; CED+PG. Ceram X Duo+PoGo; CED+SF. Ceram X Duo+Sof-Lex. The initial color and roughness were determined before and after the polishing procedures. All specimens were stored for 7 days in coffee solution and the color assessment was performed. Two specimens from each group were evaluated by scanning electron microscopy. Roughness and color data were submitted to ANOVA and Tukey tests(p<0.05). All tested materials presented color alterations after coffee solution storage; the highest ΔE values were observed for clear strips and all composite resins, as following: G4 (9h)>G7(5.8f)=G10(5.7ef)>G1(3.7c), followed by the G6(5.9f)>G9(3.1bc)=G12(2.1ab)>G3(1.7a). G3, after 7 days, presented the lowest values for ΔE(1.704). The lowest roughness values were observed when the clear strips were used regardless material type. The Sof-Lex system provided the lowest surface roughness values for all tested composite resins. Among composite resins the highest roughness values were found for Amelogen (G5-0.49 and G6-0.35), regardless polishing technique. All tested materials presented changes in color after immersion in coffee solution. The roughness surface and the staining of composite resins are material and polishing technique dependents.