One-pot synthesis of hydroxyapatite-silica nanopowder composite for hardness enhancement of glass ionomer cement (GIC)

Hydroxyapatite-silica nanopowder composite was prepared using one-pot sol-gel technique. The morphology of the powder consists of a mixture of spherical silica particles (similar to 30 nm) embedded within the elongated hydroxyapatite (similar to 103 nm). The synthesized nanoparticles were incorporated into commercial glass ionomer cement (GIC) and Vickers hardness was evaluated. Results shown that the addition of the nanopowder composite gave similar to 73% increment in the hardness compared to the pure GIC. Higher content of hydroxyapatite-silica nanopowder resulted in dense cement and produced a stronger GIC and the application of this material with improved hardness property might lead to extend the clinical indications, especially in stress bearing areas.