Evaluation of mechanical properties and bond strength of nano-hydroxyapatite-silica added glass ionomer cement

Abstract The effects of adding nano-hydroxyapatite-silica to the conventional glass ionomer cement (Fuji IX GC) matrix were investigated. Nano-hydroxyapatite-silica was synthesized using one-pot sol-gel technique, which was then characterised using fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscope and transmission electron microscope. In addition, surface hardness, compressive strength, flexural strength, and shear bond strength of the nano-hydroxyapatite-silica-glass ionomer cement composite was evaluated. It was found that nano-powder consisted of a mixture of spherical silica particles (~ 50 nm) and elongated hydroxyapatite particles in the range between 100 and 200 nm. Hardness, compressive strength, and flexural strength of nano-HA-35SiO2-GIC is statistically higher than that of nano-HA–21SiO2–GIC, nano-HA-11SiO2-GIC. Highest value for Vickers hardness (64.77 ± 6.18), compressive strength (143.42 ± 13.94 MPa) and flexural strength (17.68 ± 1.81 MPa) were recorded by addition of 10% nano-HA-35SiO2 to GIC, an increase of ∼ 36%, ∼ 19.7% and ∼ 53.34% respectively as compared to conventional GIC. 10% nano-HA–35SiO2-GIC also demonstrated higher shear bond strength as compared to conventional glass ionomer cement. The addition of nano-HA-silica to conventional GIC significantly enhanced the mechanical properties of the material. Hence, it can be suggested as a potential dental restorative material in dentistry.