Surface texture and roughness of polished nanofill and nanohybrid resin composites

Abstract

Nanofiller-containing resin composites have gained appreciable market share in dentistry due to their claims of high mechanical strength and low polymerization contraction. In this study, the polishability of one nanofill (Filtek Supreme XT/FIL) and three nanohybrid materials (Grandio/GRA, Tetric EvoCeram/TET, Venus Diamond/VED) was investigated using surface profilometry and SEM. After the specimens were cured under a Mylar strip or pre-ground with 600-grit SiC paper, three polishing systems were applied and their polishing effects compared: diamond polishing points, a diamond paste, and urethane-backed aluminum oxide disks. Except for the profilometry results obtained by glass filler-containing GRA and VED with one polishing system that comprised the consecutive application of diamond particles and a diamond polishing paste, the final roughness (Ra) of all other specimens were lower than the clinically acceptable 0.2 µm threshold. The surface textures of the polished nanofill FIL and nanohybrid TET were uniformly smooth, whereas relief polishing effects and filler extrusion of varying extents were seen on the nanohybrid composites GRA and VED.

Surface roughness and morphology of resin composites polished with two-step polishing systems

“…5b and 6b), on which Enhance/PoGo created a smoother surface topography than Venus Supra. Similarly, Endo et al 17) and Jung et al 18) described detrimental surface alteration effect of relatively large diamond particles in finishing instruments on resin composites.…”

“…Apart from traditional hybrid and micro-hybrid composites, nano-fill and nano-hybrid composites represent the state of the art in terms of filler formulation 19) . Regarding surface roughness after polishing, nano-hybrids may not perform like nanofilled composites 17,21) , but their performance is similar to or slightly better than that of micro-hybrids 21) . To our knowledge, there is no comparison in the literature of surface roughness among the micro-hybrid, nanohybrid and supra-nanofilled composites polished with two-step polishing systems.…”

“…In contrast, oneand two-step polishing systems that use elastomeric or rubberized polishers in various shapes, sizes and dimensions come into direct contact with the restoration surface and complement the access limitations of the aluminum-oxide discs. Two-step polishing systems that use diamond abrasive-impregnated polishers appear to be particularly effective in achieving high surface smoothness similar to 12,17) or better than that achieved by the multi-step aluminum-oxide-coated abrasive disc systems 18) . Thus, the success of the one-step polishing systems was found to be closely related to the initial finishing regimen 18) .…”

Comparison of surface roughness of nanofill and nanohybrid composite resin polished by aluminum oxide and diamond particle paste

“…Difference in the degree of hardness influenced the effectiveness or the action of polishing instrument. 5,9 Sen et al 9 in his research stated that bisacryl composite had a smoother surface if polished using diamond paste compared to aluminum oxide. In this research, aluminum oxide had a lower effectivity compared to diamond particle for polishing composite nanofill.…”

“…3,5 Jung et al 13 with Tetric EvoCeram (Ivoclar Vivadent), conducted a research on the surface toughness of 3 nanofill composites and one nanohybrid composite after polishing. The result from the research showed that there was one composite nanofill possessed a higher surface toughness compared to nanohybrid.…”