Characterisation and Physico-Chemical Evaluation of a Novel Glass Ionomer Nano Zirconia- Silica- Hydroxyapatite Hybrid Material

Glass ionomer cement (GIC) is among popularly used materials in prosthodontics for core build-up and cementation of prostheses. A novel GIC-nano Zirconia- Silica- Hydroxyapatite (GIC-nano ZrO2-SiO2-HA) has been developed which has better hardness and aesthetics. Aim: To characterisze and evaluate the fluoride release and colour stability of a new GIC-nano ZrO2-SiO2-HA hybrid material. Materials and Methods: The nano ZrO2-SiO2-HA was synthesiszed using modified sol-gel technique, and the nanopowder was characterized using TEM and FTIR. Ten samples per group were prepared by adding 5% by weight of nano ZrO2-SiO2-HA powder into the conventional GIC (Fuji IX). The colour stability was measured with a spectrophotometer using the CIE L*a*b* system, and the fluoride release was measured using an ion- specific electrode (ISE) meter, over a one-month period. The data wereas statistically analysed using repeated measures ANOVA. Results: TEM micrographs confirmed that all particles were in the nanoscale range with spherical ZrO2 and SiO2 particles embedded in the voids between rod-shaped HA crystallites. FTIR confirmed the presence of functional groups corresponding to each element. The statistical analysis demonstrated that the ΔE values for GIC-nano ZrO2-SiO2-HA were lower than for conventional GIC, indicative of greater colour stability, and fluoride release was significantly higher for all the time intervals (p0.05). Conclusion: The addition of nano ZrO2-SiO2-HA has improved the physico-chemical properties of GIC with greater colour stability and fluoride elusion, making it a potentially stronger anticariogenic aesthetic dental material for the future. Keywords: Sol-gel synthesis, glass ionomer, hydroxyapatite, zirconia, fluoride release