Antimicrobial Effects of Essential Oils on Anaerobic Gram-Negative Periodontal Pathogens

Willaeys, Alexandria, Teniece Roberts, Megan Patlow, Terlicia Winston, Jamal Alhabeil, and Eric Krukonis

The goal of this study was to determine the antimicrobial effects of the essential oils on gram-negative anaerobic periodontal pathogens compared to Listerine Naturals, a commercially available essential oil mouth rinse. Periodontal disease, which leads to the destruction of periodontal tissue, affects 64 million adults within the US alone. Many gram-negative microbes have been identified as causes of periodontal disease. With antimicrobial resistance increasing, people have begun to turn to organic products to combat periodontal disease and in turn improve oral health. An in vitro study was conducted in order to determine the effects of commercially available essential oils on the survival of two anaerobic gram-negative periodontal pathogens, Porphyromonas gingivalis and Prevotella intermedia. The water-soluble essential oils tested in this experiment included tea tree, oregano, eucalyptus, sage and peppermint. The antimicrobial effects of these essential oils were compared to those of Listerine Naturals, a commercially available essential oil mouth rinse. All of the essential oils tested were effective as antimicrobial agents, killing at least 90% of the bacteria compared to control. The order of activity of the essential oils was: oregano > eucalyptus > tea tree > sage and peppermint. Although eucalyptus, tea tree, sage and peppermint oils could kill both P. gingivalis and P. intermedia, overall bacterial survival rates were higher compared to the killing efficiency of Listerine Naturals. In contrast oregano oil was significantly more effective than Listerine at inhibiting both P. gingivalis and P. intermedia survival. Oregano oil therefore could serve as an effective natural product for destruction of oral bacteria.