RESUMEN
PURPOSE: To compare susceptibility to stain of three posterior composite surfaces polished with two one-step polishing systems, to test the efficiency of the re-polishing to remove the stain formed and to analyze the polished surfaces by SEM. METHODS: The resin composites tested were Clearfil Photo Posterior, SureFil and Filtek P60. The polishing systems used were Sof-Lex Brush and PoGo. Twenty-two discs of each material were fabricated and divided into two treatment groups of 11. Out of the latter, six were used for SEM evaluation for surface morphology and five for stain retention testing. The discs were roughened with silicon paper and polished for 30 seconds with each system. Specimens were immersed in coffee and distilled water for 7 days. Color measurements were made at baseline and after 1, 3, 5, and 7 days with a spectrophotometer. The specimens were then re-polished with the same systems and their colors re-measured. All comparison of color change and re-polishing were subjected to repeated measures ANOVA with a Bonferroni post hoc test (P < or = 0.05). RESULTS: After 1 week, the coffee stained all the resin composites. Clearfil Photo Posterior was the least stained composite while Filtek P60 was the most. Regardless of the materials, PoGo polishing was less susceptible to staining (P < or = 0.05). The color change could be partially removed with re-polishing. The surfaces of Sof-Lex Brush polished samples, except the Clearfil group, were scratched and thus more susceptible to stain retention.