Antimicrobial Activity of Oregano, Thyme, and Lavender Oils Against Oral Pathogens: Perspectives for AI-Supported Research

Background: Antimicrobial resistance in oral pathogens drives interest in natural alternatives such as essential oils (EOs). Methods: The chemical composition and in vitro antimicrobial activity of Origanum vulgare, Thymus vulgaris, and Lavandula angustifolia EOs were investigated. Oils were profiled by gas chromatography–mass spectrometry (GC-MS) and tested against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 using the disc diffusion method (triplicate, 1 µL/disc, ~850–950 µg). Results: O. vulgare oil produced the strongest inhibition against C. albicans (18.4 ± 0.5 mm), T. vulgaris was most active E. coli (13.0 ± 0.5 mm), while L. angustifolia showed negligible activity (6–7 mm). All EO inhibition zones were smaller than those of antibiotics. Conclusions: At clinically relevant doses, Oregano and Thyme oils showed modest antimicrobial effects, whereas Lavender was inactive. However, these findings are limited by the use of ATCC strains, small sample size, and reliance on the disc diffusion method, which provides only qualitative data and does not capture biofilm or host interactions. Future studies should include minimum inhibitory concentrations (MIC)/minimum bactericidal concentrations (MBC) assays, biofilm models, and cytotoxicity testing. AI-assisted GC-MS analysis and automated inhibition zone measurement should be considered as future perspectives to improve reproducibility and translational potential.