The aim of this study was to investigate and compare the antibacterial activity of the aqueous extract (AqE) and essential oil (EO) of Artemisia herba-alba on Porphyromonas gingivalis and Prevotella intermedia, the major pathogens of periodontitis. EO and AqE were antibacterial against P. gingivalis, with inhibition diameters ranging from 40.00±0.08 to 15.00±0.00 mm and from 31.83±0.24 to 49.00±0.82 mm respectively. In the case of P. intermedia, the inhibition diameters obtained with AqE and EO ranged from 20.50±1.08 to 36.83±1.31mm and from 34.63±0.45 to 18.33±0.47mm respectively. GC/MS analysis of the EO's chemical composition revealed a high content of oxygenated monoterpenes such as camphor, thujone and eucalyptol, known for their antibacterial activity. Similarly, total polyphenols in AqE were determined spectrophotometrically using the Folin-Cioclateu method. A linear correlation betweegerms and increasing concentrations of AqE and EO AqE and mugwort EO may be a source of natural molecules with antimicrobial properties that can be used in the management of periodontitis.