Surface roughness of nanofill and nanohybrid composite resin and ormocer-based tooth-colored restorative materials after several finishing and polishing procedures.

The purpose of this study was to evaluate the effect of several finishing and polishing procedures on the surface roughness of nanofill and nanohybrid composites and ormocer-based dental restorative materials. The materials included a nanofill composite (Supreme); a nanohybrid composite (Grandio); and an ormocer (organically modified ceramic) (Admira). Forty specimens of each material were prepared using a Mylar strip (polyester strip) and randomly divided into four finishing and polishing groups (n =10): (I) Diamond bur/Super-snap Rainbow Technique Kit(Al(2)O(2)-coated, graded abrasive discs); (II) Diamond bur/Astropol and Astrobrush system (silicone abrasive polishers and brush system); (III) Tungsten carbide bur/Super-snap Rainbow Technique Kit; and (IV) Tungsten carbide bur/Astropol and Astro-brush system. The average surface roughness (Ra) in micrometers was measured using a "Mahr Perthometer S4P" Surface Roughness Tester and the data were compared using ANOVA at P <or=0.05. The results of this study indicated that the Mylar strip produced the smoothest surface on all materials and among the finishing-polishing methods the first and the third methods performed significantly smoother surfaces than the second and the fourth methods for the three restoratives. Ormocer (Admira) performed the lowest variability in initial surface roughness among the tested materials. This study has shown that Super-snap abrasive discs produced a smoother surface than the Astropol and Astrobrush silicone polishers for composite and ormocer-based restorative materials, but the results would be valid clinically for readily accessible and flat surfaces i.e., not for all areas in the mouth. Therefore silicone polishers are necessary for posterior areas and for concave and convex surfaces.