Impact of filler size and distribution on roughness and wear of composite resin after simulated toothbrushing

Abstract

ObjectivesNanofilled composite resins are claimed to provide superior mechanical properties compared with microhybrid resins. Thus, the aim of this study was to compare nanofilled with microhybrid composite resins. The null hypothesis was that the size and the distribution of fillers do not influence the mechanical properties of surface roughness and wear after simulated toothbrushing test. Material and methodsTen rectangular specimens (15 mm x 5 mm x 4 mm) of Filtek Z250 (FZ2), Admira (A), TPH3 (T),Esthet-X (EX), Estelite Sigma (ES), Concept Advanced (C), Grandio (G) and Filtek Z350 (F) were prepared according to manufacturer's instructions. Half of each top surface was protected with nail polish as control surface (not brushed) while the other half was assessed with five random readings using a roughness tester (Ra). Following, the specimens were abraded by simulated toothbrushing with soft toothbrushes and slurry comprised of 2:1 water and dentifrice (w/w). 100,000 strokes were performed and the brushed surfaces were re-analyzed. Nail polish layers were removed from the specimens so that the roughness (Ra) and the wear could be assessed with three random readings (µm). Data were analyzed by ANOVA and Tukey's multiple-comparison test (α=0.05). ResultsOverall outcomes indicated that composite resins showed a significant increase in roughness after simulated toothbrushing, except for Grandio, which presented a smoother surface. Generally, wear of nanofilled resins was significantly lower compared with microhybrid resins. ConclusionsAs restorative materials suffer alterations under mechanical challenges, such as toothbrushing, the use of nanofilled materials seem to be more resistant than microhybrid composite resins, being less prone to be rougher and worn.

Localized and Generalized Simulated Wear of Resin Composites

“…Studies have shown that the type of glass, shape, and size of filler components, resin matrix formulation, and degree of polymerization have a significant effect on the wear characteristics of resin composite materials. [41][42] It is interesting to note the similarity of Z and SU on the argon-etched SEM examinations ( Figure 5B,G). The manufacturing process appears to result in similarly shaped filler particles, which are mostly rounded.…”

Impact of a novel polishing method on the surface roughness and micromorphology of nanofilled and microhybrid composite resins

“…In fact, Filtek Z350XT showed a smoother surface than Filtek Z250 when specimens were subjected to none of the finishing/polishing treatment (control 1 group), which was also found previously. 13 This result can be explained by the smaller volume and less homogenous …”

Investigation of Bacterial Adhesion on Nanoparticle Filler-Reinforced Dental Composites after Different One-Step Finishing Timing Using a Constant-Depth Film Fermenter

“…The literature suggests that filler size has the potential to influence the surface characteristics of composite [30][31][32]. This may suggest that nano-filler incorporation response to finishing timing were similar since the ability to produce a smooth surface with the use of the aluminum oxide disks depends on their cutting filler particles and matrix resin equally [33,34]. Since the nanoparticle filler-reinforced dental composites used in this study were highly filled hybrid composites with relatively large filler particles, further investigation focusing specifically in high content nanofiller is a need.…”