TiO₂ Nanotechnology Improves Physical-Chemical-Biological Properties of Glass Ionomer Cement

Objectives: Titanium dioxide (TiO₂) has been identified as a promising compound that can improve the performance of dental materials. This in vitro study evaluated physical, chemical and biological properties of a conventional glass-ionomer cement (GIC, Ketac Molar EasyMix™) that was incorporated with TiO₂ nanotubes.
Methods: The powder component of GIC was incorporated with TiO₂ nanotubes [3%, 5% and 7% (w/w)], and unblended powder was used as the control. Physical-chemical and biological analysis included: i) spectroscopy energy dispersive (EDS); ii) surface roughness (SR); iii) Knoop hardness (SH); iv) fluoride releasing analysis; v) cytotoxicity by MTT assay; vi) cell morphology by scanning electron microscopy (SEM); and vii) extracellular matrix composition (ECM, Sirius red/fast green staining). EDS, SR and SH data analysis was performed using one-way ANOVA and Tukey’s post-hoc test\(α ≤0.05). Kruskal-Wallis and Friedman tests were used for fluoride release and ECM data, and a two-way ANOVA was performed for MTT data (α≤0.05).

Results: EDS Data detected Ti in experimental groups with 5 and 7% TiO₂. The addition of 5% TiO₂ nanotubes in GIC significantly improved GIC physical-chemical properties without causing detrimental effects to the cells, compared to GIC+3% TiO₂ or to GIC alone. GIC-containing 7% TiO₂ showed a decreased in SH. The addition of TiO₂, regardless of concentration, had no effect on SR values. Fluoride release lasted over a longer time period in GIC groups with 5 and 7% TiO₂.

Conclusions: The addition of 5% TiO₂ nanotubes to conventional GIC may represent a promising strategy to improve the GIC’s physical-chemical properties without affecting its biological performance.