Influence of nanometer scale particulate fillers on some properties of microfilled composite resin

Abstract

The aim of this study was to evaluate the effect of different weight fractions of nanometer sized particulate filler on properties of microfilled composite resin. Composite resin was prepared by mixing 33 wt% of resin matrix to the 67 wt% of silane treated microfine silica particulate fillers with various fractions of nanometer sized fillers (0, 10, 15, 20, 30 wt%) using a high speed mixing machine. Test specimens made of the composites were tested with a three-point bending test with a speed of 1.0 mm/min until fracture. Surface microhardess (Vicker's microhardness) was also determined. The volumetric shrinkage in percent was calculated as a buoyancy change in distilled water by means of the Archimedes principle. The degree of monomer conversion (DC%) of the experimental composites containing different nanofiller fractions was measured using FTIR spectroscopy. Surface roughness (Ra) was determined using a surface profilometer. Nanowear measurements were carried out using a nanoindentation device. The water uptake of specimens was also measured. Parameters were statistically analysed by ANOVA (P < 0.05). The group without nanofillers showed the highest flexural strength and modulus, DC% and Ra value. The group with 30% nanofillers had the highest water uptake and volumetric shrinkage. No significant difference was found in Vicker's microhardness and the nanowear of the composites. The plain microfilled composite demonstrated superior properties compared to the composites loaded with nanofillers with the exception of surface roughness.

Effects of Filler Size on the Mechanical Properties of Polymer-filled Dental Composites: A Review of Recent Developments

“…65 Moreover, Garoushi et al incorporated SiO 2 (20 nm) into micro-filled composite resin with loadings of 10, 15, 20 and 30 wt%. 66 The results of these four studies showed that neat resins have higher flexural strength than nano-composites. Table 4 shows the negative effects of nanoparticles on the flexural strength of dental composites.…”

“…81,82 The surface area for the interaction between nanofillers and matrix decreases and fractures in the agglomerate sites are initiated. 66,83 4. Decreased cross-section of the load-bearing matrix.…”

Preparation of antibacterial and radio-opaque dental resin with new polymerizable quaternary ammonium monomer

“…Volumetric polymerization shrinkage of dental resin was measured according to the method reported previously [21]. The specimen's densities (n = 5 per group) were measured to determine polymerization shrinkage using Archimedes' principle with a commercial Density Determination Kit of the analytical balance Mettler Toledo X (Mettler Instrument Co., Highstone, NJ, USA).…”

Effects of polymerization method on flexural and shear bond strengths of a fiber-reinforced composite resin

“…Clearly, factors required for high bond strengths between fiber and composite have been thoroughly investigated. In general, the mechanical properties of polymerized composite resin materials are related to monomer type (18) and filler type (19).…”