Green Synthesis of TiO₂ and Ag/TiO₂ Nanoparticles Using <i>Rosmarinus officinalis</i> and <i>Syzygium aromaticum</i> Extracts for Potential Dental Applications

Green nanotechnology provides sustainable alternatives for synthesizing functional materials with biomedical potential. This study reports the green synthesis of titanium dioxide (TiO₂) and silver (Ag) nanoparticles using aqueous extracts of Rosmarinus officinalis (rosemary, RO) and Syzygium aromaticum (clove, CL) as natural reducing and stabilizing agents. UV–Vis spectroscopy confirmed nanoparticle formation, with TiO₂ showing its characteristic absorption band and Ag/TiO₂ composites exhibiting a bathochromic shift indicative of Ag–TiO₂ interactions. Scanning electron microscopy revealed predominantly spherical nanoparticles, averaging ~165 nm for TiO₂ and ~96 nm for Ag deposits, while energy-dispersive spectroscopy verified elemental composition. Antibacterial assays demonstrated markedly enhanced activity of Ag/TiO₂ nanocomposites compared to TiO₂ alone, with effective inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, although lower efficacy was observed against Enterococcus faecalis. Interestingly, TiO₂ nanoparticles synthesized with CL extracts exhibited selective antibacterial effects, while RO-based coatings appeared to reduce antimicrobial performance. The combined bioactivity of plant-derived phytochemicals and Ag/TiO₂ nanostructures highlights a synergistic approach for developing biocompatible, eco-friendly antibacterial agents. These results suggest that RO- and CL-mediated Ag/TiO₂ nanocomposites hold promise as adjunctive materials in restorative dentistry, particularly for pulpotomy applications where antibacterial efficacy is essential.