Bulk and surface properties related to composite filler size|
Gerhardt, Kátia; da Silva, Andrea Soares Quirino; Rego, Guilherme; Sinhoreti, Mário Alexandre Coelho; Salgado, Vinicius Esteves & Schneider, Luis Felipe J.
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 (ΔE*) 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 ΔE*. All
comparisons were performed by Tukey’s test (5%). Pearsons’ correlation test was performed to
determine the correlation between EM, FS, roughness, gloss, and ΔE* 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 ΔE*. 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.
nanocomposites; resin cements; surface properties