How TiO₂ Nanomaterials are Emerging as Key Therapeutics in Stomatology

Conventional treatments for oral diseases-such as cancer and tissue defects-are often limited by high invasiveness, suboptimal efficacy, and drug resistance. In recent years, titanium dioxide (TiO₂) nanomaterials have demonstrated remarkable therapeutic potential in the field of oral medicine. This review systematically evaluates the current applications and future prospects of TiO₂ and its reduced form (TiO_{2- x}) nanomaterials across six major domains: cancer diagnosis and therapy, antibacterial treatment, tissue regeneration, drug delivery, restorative dental materials, and teeth whitening, based on an extensive literature search of databases including PubMed and Web of Science. The findings reveal that TiO₂ nanomaterials exhibit exceptional multifunctionality through various mechanisms: (1) surface-enhanced Raman spectroscopy (SERS) substrates achieve 100% sensitivity and 95.83% specificity in diagnosing oral squamous cell carcinoma; (2) reactive oxygen species (ROS)-mediated antibacterial efficiency exceeds 99% against key oral pathogens; (3) modified implant surfaces show a 1.5-fold increase in bone-implant contact; and (4) the incorporation of only 0.06% TiO₂ nanoparticles enhances resin hardness by over 200%. Notably, TiO_2-x exhibits visible/near-infrared responsiveness, photothermal conversion capacity, and peroxidase-like activity, enabling 12% H₂O₂-based whitening outcomes comparable to commercial 40% H₂O₂ products. Collectively, TiO₂-based nanomaterials represent a paradigm shift toward precision oral medicine, owing to their excellent biocompatibility, multifunctional therapeutic mechanisms, and broad application potential. Nonetheless, successful clinical translation requires addressing critical challenges, including synthesis standardization, comprehensive biosafety evaluation, optimization of interfacial bonding strength, and the development of regulatory frameworks tailored to dental nanomedicine.