To synthesize and characterize green-mediated titanium dioxide– and chitosan-modified glass ionomer cement and compare their antimicrobial, mechanical, and surface properties with conventional GIC. Titanium dioxide nanoparticles were synthesized using Azadirachta indica extract and incorporated into GIC to produce TiO₂-GIC. Chitosan-modified GIC (Chi-GIC) was prepared using chitosan synthesized with Eucalyptus globulus extract. Three groups were evaluated: TiO₂-GIC, Chi-GIC, and conventional GIC (control). Characterization was performed using Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Specimens were tested for antimicrobial activity, surface roughness, microhardness, and compressive strength. Data were analyzed using one-way ANOVA and Tukey post-hoc tests (p < 0.05). Chi-GIC showed the highest antibacterial activity against Streptococcus mutans (19.37 ± 1.24 mm) and Lactobacillus acidophilus (18.41 ± 1.19 mm), followed by TiO₂-GIC and conventional GIC. TiO₂-GIC exhibited the highest microhardness (78.42 ± 3.15 VHN) and compressive strength (165.42 ± 8.36 MPa) with the lowest surface roughness (0.82 ± 0.07 µm). Nanoparticle incorporation significantly improved properties (p < 0.05). Green-mediated incorporation of titanium dioxide nanoparticles and chitosan significantly enhanced GIC performance. TiO₂-GIC improved mechanical properties, whereas Chi-GIC demonstrated superior antibacterial activity.
