the effect of silica nanoparticles on the mechanical properties of fiber reinforced composites

background and aim: this study investigated the reinforcing effect of silica nanoparticles when incorporated into the matrix phase of an experimental dental fiber reinforced composites (frc) through the evaluation of the flexural properties of the composites. materials and methods: in this experimental study frc samples were divided into two main groups (containing two or three bundles) either of them consist of five subgroups incorporating 0, 0.2, 0.5, 2 and 5 wt.% of silica nanoparticles in the matrix resin (n=10 in each subgroup); while a commercial frc (angelus, brazil) was used as control group (n=10). three point bending test was performed for evaluating the flexural strength and modulus. thereafter, the microstructure of the fractured samples was evaluated using scanning electron microscopy (sem). the results were analyzed using one way anova and tukey's hsd tests. result: the results revealed that the silica nanoparticles had a significant positive effect on the flexural strength and modulus of the frcs (p 0.05) in either groups incorporating two or three bundles of fibers. conclusion: incorporating silica nanoparticles into the frc resin phase resulted in the composites with improved properties.