A Comparative Study of Bioactivity and Mechanical Properties of Micro and Nano Dental Glass Ionomer Cement Particles

Lack of information about different glass ionomer cements (GICs) in Iran’s market makes it necessary to conduct further studies about production of glass ionomer cement. The purpose of this study was preparation and characterization of glass ionomer cements nanoand microparticles and comparing their mechanical properties and in vitro bioactivity. The nanoparticles of the ceramic part of GIC were prepared using sol-gel method with particle size less than 80 nm and microparticles of the ceramic part of GIC were produced through melting method with particle size less than 70 µm. XRD, XRF, SEM and TEM examinations were used to evaluate phase structure, chemical composition and particles’ morphology. For investigating the in vitro bioactivity, samples were immersed in the simulated body fluid (SBF) for 28 days. Scanning electron microscope (SEM) was used for confirmation of the apatite layer formation on the surface of glass ionomer cements. Also, the compressive strength of the samples was determined and compared. One-way ANOVA was used for data analysis. The results confirmed the production of GIC using the sol-gel and melting technique. Amorphous and glassy structure of GIC powders and their proper chemical composition were verified by characterization tests. The result of soaking in SBF showed that nGIC had higher bioactivity in comparison to µGIC. The compressive strength measurements showed that nGIC had higher compressive strength in comparison to µGIC. All these results confirmed higher in vitro bioactivity and compressive strength of nano glass ionomer cements compared to macro glass ionomer cements.