Magnolia figo Extract Induces Enamel Shade Recovery and Inhibits Porphyromonas gingivalis Biofilm Formation: An In Vitro, Dual-Action Natural Therapeutic Approach

Dental enamel discoloration, extrinsic staining, and periodontal biofilms remain persistent challenges in oral health. This study explores the in vitro, dual-functional potential of Magnolia figo flower extract (FMO), a sesquiterpene-rich botanical active phytochemical ingredient (API), for aesthetic and antimicrobial oral applications. FTIR identified characteristic terpenoid and long-chain fatty acid functional groups, including β-elemene, γ-elemene, and caryophyllene oxide. Whitening efficacy on coffee-stained bovine enamel was quantified using CIELAB colorimetry. The 0.5% FMO treatment achieved ΔE* = 8.49, which was within the clinical perceptibility threshold and the optimal biocompatibility balance. SEM confirmed no demineralization on the enamel surface after immersion in 3.0% FMO for 12 h. Antimicrobial assays demonstrated inhibition of Porphyromonas gingivalis, with MIC and MBC values of 0.25% and 0.5%, respectively. Biofilm formation was reduced by over 50% at a 0.148% concentration. Cytocompatibility assays using HGF-1 cells with various concentrations of FMO showed reduced cell viability at higher concentrations. When exposed for 5 min (simulating daily oral care) or 2 h, 0.5% FMO exhibited greater biocompatibility with L929 cells compared to toothpaste and peroxide-based agents. These findings suggest that FMO may serve as a natural candidate for dual-function oral care; however, further in vivo and clinical investigations are needed to validate its potential use within oral care treatments.