Quantum dots in periodontology: emerging promise and translational challenges.

Periodontitis is a chronic inflammatory disease driven by microbial dysbiosis, resulting in irreversible destruction of the periodontal ligament and alveolar bone. Conventional therapies, including mechanical debridement and local drug delivery, frequently fail to achieve adequate outcomes in advanced disease due to poor biofilm penetration, limited site-specificity, and the inability to modulate the host immune microenvironment. Quantum Dots (QDs) are semiconductor nanocrystals measuring 1-10 nm, which possess unique size-dependent photoluminescence, high photostability, broad excitation profiles, and versatile surface functionalization, properties that have not yet been systematically evaluated in the context of periodontology. This review evaluates QD applications across four domains: diagnostics and bioimaging, targeted therapeutics and local drug delivery, tissue engineering and regeneration, and dental implantology. In diagnostics, QDs enable ultrasensitive detection of salivary and crevicular inflammatory biomarkers, real-time pathogen imaging, and integration into wearable point-of-care platforms. Therapeutically, they facilitate photodynamic antimicrobial therapy, stimuli-responsive drug release, and improved bioavailability of agents such as curcumin and metformin. In regeneration, they promote osteogenic stem cell differentiation and immunomodulation of the local inflammatory microenvironment. On implant surfaces, they enhance antibacterial activity and osseointegration. Despite this breadth, clinical translation remains constrained by cytotoxicity of heavy-metal-based variants, physicochemical instability in the oral environment, and the absence of long-term