Polydopamine-Based Biomaterials in Oral Medicine: Applications, Mechanisms, and Translational Challenges

Polydopamine (PDA) is a mussel-inspired polymeric material that has attracted increasing attention in oral medicine owing to its universal adhesion, favorable biocompatibility, redox activity, photothermal conversion, and versatile surface functionalization. This narrative review summarizes recent advances in PDA-based materials and discusses their potential applications, current limitations, and translational prospects in oral medicine. PDA can be prepared through oxidative self-polymerization, electrochemical polymerization, or enzymatic oxidation, and its morphology, coating thickness, and interfacial properties can be regulated by reaction conditions such as pH, dopamine concentration, temperature, and oxidation environment. In oral hard tissue applications, PDA is widely used to modify titanium, zirconia, magnesium alloys, and bone-repair scaffolds, where it improves surface hydrophilicity, enhances protein adsorption and cell adhesion, promotes osteogenic differentiation, facilitates hydroxyapatite mineralization, and supports osseointegration. PDA-based coatings and hydrogels also show promise in oral soft tissue repair by improving wet adhesion, providing antioxidative protection, regulating local inflammation, and enabling sustained delivery of bioactive molecules. In drug delivery, antibacterial/anti-inflammatory systems, and oral tumor therapy, PDA serves as a multifunctional platform for loading therapeutic agents, metal ions, antimicrobial peptides, or nanoparticles, thereby enabling responsive release, biofilm inhibition, reactive oxygen species regulation, and photothermal or photodynamic antibacterial effects. In addition, PDA-based sensing interfaces have been explored for salivary biomarker detection and oral disease diagnosis through electrochemical, fluorescence, colorimetric, and surface-enhanced Raman strategies. Despite these advantages, most PDA-related studies in oral medicine remain at the preclinical stage. Key unresolved issues include unclear polymerization mechanisms, limited long-term stability data under dynamic oral conditions, incomplete degradation and biosafety evaluation, manufacturing reproducibility, and insufficient clinical evidence. Future studies should emphasize standardized preparation, evidence-weighted evaluation, long-term oral-environment simulation, large-animal validation, and well-designed translational studies.