Bulk and surface properties related to composite filler size

Abstract

There are few studies that fully characterize the effect of the filler size on the surface, optical and mechanical properties of resin composites. Aim: To determine the influence of the filler size content on surface, optical and mechanical properties before and after accelerated aging. Methods: Seven resin composites were investigated: Filtek Supreme® (3M/ESPE), Estelite Σ Quick® (Tokuyama), Evolu-X® (Dentsply), Esthet-X HD® (Dentsply), Opallis® (FGM), Herculite XRV Ultra® (Kerr) and Filtek Z250® (3M/ESPE). Elastic modulus (EM) and flexural strength (FS) were determined by three-point bending of specimens immersed or not in absolute ethanol for seven days. Roughness (Ra) and gloss (G.U.) analyses were determined before and after ethanol storage for seven days and CIELAB color change (∆E*) was obtained with a spectrophotometer. Results were analyzed by two-way ANOVA (general linear model) for EM and FS, with repeated measures for roughness and gloss, and one-way ANOVA for ∆E*. All comparisons were performed by Tukey's test (5%). Pearsons' correlation test was performed to determine the correlation between EM, FS, roughness, gloss, and ∆E* with the mean filler sizes. Results: Mechanical properties decreased for all materials when submitted to immersion in ethanol. Increasing filler size gradually increased EM, FS and roughness values; gloss values decreased and didn't significantly affects ∆E*. Nanofiller composites presented higher gloss values than the others. Conclusions: It was possible to determine that the average filler size is a good predictor just for FS and gloss retention.

Evaluation of colour change and surface roughness of two resin-based composites when exposed to beverages commonly used by children: an in-vitro study

“…The ageing of composite resins is an outcome of combined factors in the oral cavity such as pH and temperature variations, exposure to mechanical forces as well prolonged storage in water/ethanol (Çelik et al 2011). Considering that immersion of composite resin in different solutions is part of the ageing process (de Moraes et al 2008); hence, the colour results of the present study agree with Gerhardt et al (2013). The author concluded that there was no significant difference in colour change between Filtek Z250 and Filtek Supreme after accelerated aging.…”

Effect of preheating and light-curing unit on physicochemical properties of a bulk fill composite

“…Degree of cross-linking in the network of polymeric materials has been indirectly evaluated by polymer softening after ethanol storage 10. The absorption of alcohol molecules by the polar portion of the organic content causes swelling of resin matrix 15. Moreover, insufficient branched polymer is more susceptible to enzymatic attack and plasticization effect by chemical substances that enter during eating and drinking 16…”

<p>The Effects of Irradiance on Translucency and Surface Gloss of Different Bulk-Fill Composite Resins: An in vitro Study</p>

“…[25][26][27] In the present study, Filtek One showed the highest gloss value among all the materials when using a lowintensity light cure; this could be explained by the nanofiller technology. Gerhardt et al 28 found that the filler size affected the surface gloss. They concluded that a small filler size resulted in a higher surface gloss.…”