Characterization and enhancement of physico-mechanical properties of glass ionomer cement by incorporating a novel nano zirconia silica hydroxyapatite composite synthesized via sol-gel

In restorative dentistry, there has been a growing shift towards using nanoparticles dispersed in the polymer matrix to improve properties of dental restorative materials. A new nano zirconia-silica-hydroxyapatite (nanoZrO(2)-SiO2-HA) was synthesized by one-pot synthesis and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX) and dot mapping. The effect of addition of nanoZrO(2)-SiO2 -HA to the conventional GIC (cGIC) on the compressive strength, flexural strength and surface roughness was also evaluated. The characterization studies confirmed that all particles were in the nanoscale range with spherical zirconia and silica particles embedded in the voids between rod-shaped HA crystallites. The nano particles were evenly and homogenously dispersed throughout the sample with high density patterns visible for zirconia, calcium and phosphorus. The incorporation of 5% nanoZrO(2)-SiO2-HA has resulted in considerable improvement in the compressive and flexural strengths of cGIC. The GIC 5% nanoZrO(2)-SiO2-HA exhibited an increase in compressive (144.12 +/- 13.88 MPa) and flexural strength (18.12 +/- 2.33 MPa) over cGIC which was statistically significant (p <= 0.05). It also demonstrated surface roughness profile (0.15 +/- 0.029 mu m) similar to that of cGIC (0.15 +/- 0.019 mu m). Therefore, the nanoZrO(2)-SiO2-HA can be a promising filler for GIC to be used as restorative dental material in high stress bearing areas.