Epigallocatechin gallate in dentistry: Therapeutic applications, biomaterial integration, and translational challenges.

Epigallocatechin gallate (EGCG), a major bioactive catechin in green tea, has attracted increasing attention in dentistry because of its antioxidant, anti-inflammatory, antimicrobial, matrix-modulating, and regenerative properties. This narrative review summarizes current evidence on the biological mechanisms, dental applications, and translational challenges of EGCG in oral healthcare. EGCG can modulate oxidative stress and inflammatory signaling pathways, including nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1), and NOD-like receptor family pyrin domain containing 3 (NLRP3)-related responses, and has activity against oral disease-associated microorganisms and biofilms. In periodontal therapy, EGCG has been investigated as an adjunct to non-surgical periodontal treatment and as a local therapeutic agent through gingival patches, injectable hydrogels, and other delivery systems. In adhesive and restorative dentistry, EGCG may improve resin-dentin interface stability through matrix metalloproteinase inhibition, dentin biomodification, and antimicrobial effects against cariogenic biofilms. In regenerative dentistry, EGCG has been reported to promote osteogenic and odontogenic differentiation, regulate immune responses, support angiogenesis, and enhance bone-related repair when incorporated into scaffolds, membranes, hydrogels, or bioactive coatings. However, most evidence remains derived from in vitro and preclinical studies, and clinical translation is limited by low bioavailability, chemical instability, dosage variability, delivery efficiency, material compatibility, and insufficient long-term clinical evidence. Further studies using standardized protocols, optimized delivery systems, long-term safety assessment, clinically relevant oral models, comparative biomaterial testing, mechanism- based outcome measures, and well-designed randomized clinical trials are required to determine whether EGCG can become a reliable adjunctive strategy for periodontal, restorative, and regenerative oral healthcare.