The Impact of Zirconium Oxide Nanoparticles on the Mechanical and Physical Properties of Glass Ionomer Dental Materials.

Glass ionomer cements (GICs) have been clinically attractive dental restorative materials for many years and are widely used as luting, lining, and restorative materials. However, these materials still have limitations in terms of weak physio-mechanical properties. The aim of the study was to evaluate the effect of zirconium oxide nanoparticles (nano-ZrO particles) on the physical and mechanical properties of two commercially available GICs. Four groups were prepared for each material: the control group (without nanoparticles) and three groups modified by the incorporation of nanoparticles at 2, 5, and 7 weight% (wt%). Firstly, the morphology and size of the nanoparticles were evaluated via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Secondly, flexural strength, flexural modulus, Vickers hardness, water sorption, and solubility were evaluated. The main effect plots revealed that the addition of nano-ZrO particles enhances flexural strength, flexural modulus, and water sorption of GICs at a 7 wt% concentration and Vickers hardness at a 2 wt% concentration. The SEM analysis clearly shows that the cracks became narrower with the addition of nano-ZrO particles, whereas these cracks were completely closed at 7% nano-ZrO particles. The findings of the study appear promising, and it is anticipated that the optimization of nano-ZrO particles may aid the development of improved materials for load-bearing restorations.