Effect of finishing/polishing systems on the surface roughness of novel posterior composites

The aim of this in vitro study was to evaluate and compare the surface finish of some direct posterior resin composites with new novel ones, which are based on a resin matrix other than the ordinary dimethacrylate, after fine finishing and polishing with eight different systems.

Forty-eight disk-shaped specimens of the posterior composites were prepared in a split Teflon mold and irradiated by an Astralis 10 light cure (560 mW/cm(2) for 10 seconds) at four quadrants on each sample's side. The specimens were divided into eight groups according to the designed finishing and/or polishing protocols. The surface roughness in the form of surface finish (Ra) was recorded using a contact profilometer. The surface of the specimens was observed under the scanning electron microscope.

Analysis of variance revealed highly significant differences between the materials for the Ra roughness parameter at each finishing and polishing system used (p < 0.05). On the one hand, Filtek P90 (3M ESPE Dental Products, Seefeld, Germany) and Definite (Degussa, Dental Centrum, Hanau, Germany) provided the smoothest surface finish (Ra) when they were finished and polished with a series of Sof-Lex pop-on disks (3M ESPE Dental Products) and Astropol (Ivoclar Vivadent, Schaan, Liechtenstein), respectively. On the other hand, Filtek P60 (3M ESPE Dental Products) presented the roughest surface when it was finished with Fini disks (Jeneric/Pentron Clinical Technologies, Wallingford, CT, USA). Scanning electron microscope images indicated a uniform surface topography for Filtek P90 with most finishing/polishing systems. Contrary to CompoSite polishers (Shofu Inc., Kyoto, Japan), Astropol showed the smoothest surface finish with most of the investigated composites. CLINICAL SIGNIFICANCE The smoothest surface finish was achieved by most of the finishing/polishing systems investigated specifically on cationic (Filtek P90) and organically modified ceramics (Definite) composites compared with dimethacrylate-based composites, suggesting their successful clinical use.