Influence of the nanostructural characteristics of inorganic fillers on the physical properties of resin cements.

Light-curing resin cements, each comprising one of five different inorganic fillers (non-porous and porous spherical SiO particles, irregularly shaped glass and ZrO particles, and porous ZrO spheres), monomers, and polymerization initiators were prepared to determine the effect of filler morphology on the adhesive strength of the resin cement. The strength of adhesion to a computer-aided design/computer-aided manufacturing (CAD/CAM) resin block was investigated mechanically by measuring the tensile bond strength, flexural strength, and elastic modulus. The resin cement containing sub-micron porous ZrO spheres had significantly higher tensile bond strength than the other resin cements. The resin cement containing the porous ZrO spheres had markedly lower flexural strength and elastic modulus values than the resin cements containing SiO and glass fillers.