Surface roughness of nanofill and nanohybrid resin composites after polishing and brushing.

PURPOSE: The purpose of this study was to compare the surface roughness of nanofill (Filtek Supreme XT dentin shade and transparent shade, Filtek Z350, and Estelite Sigma), nanohybrid (Tetric EvoCeram, Ceram X, and Premise), and microhybrid resin composites (Filtek Z250, Tetric Ceram, and Clearfil AP-X) with the materials after polishing or brushing.
MATERIALS AND METHODS: Forty specimens of each resin composite were polymerized for 40 seconds under a matrix strip in cylindrical molds. Each type of polymer was divided into four subgroups: unpolished, polished with abrasive disks (Sof-Lex), polished with silicone-impregnated polishing devices (Astropol), and brushed with a toothbrush (Oral B) and toothpaste (Colgate). The surface roughness of each specimen was determined using a contact stylus profilometer and by observation under a scanning electron microscope.
RESULTS: No significant differences in surface roughness among the materials were found on unpolished surfaces. For the nanofill resin composites, there were no significant differences in surface roughness between the two polishing methods or among the unpolished surfaces. After brushing, the surfaces of all materials, except those made from Filtek Z350 and Filtek Supreme XT (dentin), had greater roughness than unpolished surfaces and surfaces polished with either abrasive disks or silicone devices. The scanning electron microscope studies revealed that the surface irregularities of the materials corresponded to the results obtained using the surface roughness tester. CLINICAL SIGNIFICANCE: The use of nanofill resin composites made with nanoclusters demonstrated the smoothest surfaces after polishing and brushing.