Vol. 9, Issue 9, Part A (2025)

Inorganic metallic nanoparticles (NPs)-including silver (Ag), zinc oxide (ZnO), titanium dioxide (TiO₂), gold (Au), copper oxide (CuO), and iron oxide (Fe₃O₄)-represent a transformative advancement in dental materials science. At the nanoscale (1-100 nm), these materials exhibit distinctive physicochemical properties such as high surface-to-volume ratio, surface plasmon resonance (SPR), photocatalytic activity, and controlled ion release, all of which enable a wide spectrum of applications beyond the limitations of conventional passive restorations.
The clinical potential of these nanoparticles derives from their tunable parameters, including size, shape, crystallinity, and surface functionalization. Various synthesis strategies-chemical reduction, physical ablation, sol-gel, hydrothermal, and environmentally friendly green biosynthesis-provide precise control over these properties. When incorporated into dental materials, nanoparticles enhance antimicrobial activity, reduce bacterial adhesion, promote remineralization, and enable photothermal or photoactivated disinfection. As summarized in Tables 1, 2, Ag and ZnO are especially effective in restorative and endodontic applications, TiO₂ demonstrates photocatalytic disinfection, and Au serves as a platform for advanced diagnostic and sensing technologies.
Despite these benefits, significant barriers hinder clinical translation. As outlined in Table 3, challenges include cytotoxicity at high concentrations, nanoparticle aggregation in complex oral environments, formation of a biologically active protein corona, and the absence of standardized synthesis and regulatory frameworks. Addressing these concerns is crucial to ensuring reproducibility, long-term biocompatibility, and patient safety.
Looking forward, the development of smart nanocomposites with pH-responsive ion release, multifunctional hybrid systems such as Ag-ZnO, AI-driven nanoparticle design, and integration into 3D printing technologies are highlighted as future directions (Table 4). By uniting advances in inorganic chemistry, nanotechnology, and clinical dentistry, inorganic metallic nanoparticles hold strong potential to reshape modern oral healthcare into a preventive, precise, durable, and biologically integrated practice.