Investigation of the Cytotoxicity and Anti-inflammatory Properties of Glass Ionomer Cement Containing Titanium Dioxide Nanoparticles

Glass Ionomer Cements (GICs) modified with bioactive Nanoparticles (NPs) have emerged as promising materials for enhanced performance in restorative dentistry. This study aimed to evaluate the cytotoxicity and anti-inflammatory properties of a novel GIC formulation incorporating titanium dioxide (TiO₂) nanoparticles.

In this in vitro investigation, TiO₂ NPs were incorporated into conventional GIC powder (Fuji II) at a concentration of 1 wt%. Human Gingival Fibroblasts (HGFs) were cultured in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with Fetal Bovine Serum (FBS) and antibiotics. Cytotoxicity was assessed using the MTT assay at 24, 48, and 72 hours following exposure to the modified and unmodified GIC. To evaluate anti-inflammatory effects, HGFs were treated with either conventional GIC or TiO₂-modified GIC for 24 hours. Untreated cells served as the control group. Following treatment, all groups were stimulated with 45 µg/mL lipopolysaccharide (LPS) to induce an inflammatory response. The concentrations of IL-6 and TNF-α were quantified using sandwich ELISA kits. Statistical analysis was performed using one-way and two-way ANOVA followed by Tukey’s post hoc test, with significance set at p < 0.05.

The incorporation of TiO₂ NPs did not significantly alter the cytotoxicity of GIC (p > 0.05). Both modified and unmodified GICs exhibited cytotoxic effects within the first 24 hours, with cell viability ranging from 55% to 60%. No significant differences in cytotoxicity were observed across the 24, 48, and 72-hour time points (p > 0.05). LPS stimulation significantly elevated IL-6 and TNF-α levels in all groups (p < 0.001), confirming robust immune activation. Notably, conventional GIC further enhanced IL-6 production in the presence of LPS (p < 0.01). In contrast, TiO₂-modified GIC significantly attenuated the expression of both cytokines under inflammatory conditions (p < 0.01). Under non-stimulated conditions, cytokine levels remained low and did not differ significantly from the control group.

The findings suggest that the addition of low-dose TiO₂ NPs does not exacerbate the cytotoxic effects of GIC and may confer anti-inflammatory benefits, thereby enhancing the biological performance of GICs in restorative applications.

The presence of TiO₂ NPs significantly decreased the expression of proinflammatory cytokines, suggesting a potential immunomodulatory benefit.