YueWang Y, et al. - An investigation was undertaken regarding the antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil (CBEO) and its principal constituent cinnamaldehyde against Porphyromonas gingivalis and to elucidate the antibacterial mechanism. In this study, CBEO displayed a strong antibacterial activity against planktonic P. gingivalis. Thereby suggesting that CBEO could be used as a natural antimicrobial agent against periodontal disease.