Effect of incorporating nano-particles of hydroxyapatite on bioactivity and compressive strength of dental glass-ionomer cements

Glass-ionomer cements (GICs) are one of the most important restorative materials in dentistry. Similarly, hydroxyapatite (HA) is of the most well known bioceramics. The aim of this study was to prepare a type of glass-ionomer cement with nano-particles of hydroxyapatite to improve GIC bioactivity and compressive strength. Natural HA particles were extracted from animal bone. The ceramic component of GIC was produced by melting and characterized. HA particles were incorporated into the cement component of GI at 1, 3, 5 and 7 weight percentages. Bioactivity and compressive strength of GIC\HA composite were evaluated in a simulated body fluid (SBF). One-way ANOVA was used for data analysis (n = 3). The results of characterization tests confirmed the production of GIC using the melting technique. Amorphous and glassy structure of GIC powder and its proper chemical composition were verified by characterization tests. The results of soaking test in SBF showed increased bioactivity of GIC/HA composite. Finally, the results of compressive tests showed that incorporating HA up to 5 wt% would not decrease the compressive strength of GIC. GIC/HA nano-composite with 5 wt% of HA was the most appropriate sample regarding its bioactivity and mechanical properties for dental applications. Introducing this novel nano-composite can play an important role in improving the properties of glass-ionomer cements.