Comparison of Minimum Inhibitory Concentrations of Hypericum Perforatum L. Essential Oils, 0.2 % Chlorhexidine and 10 % Povidone-iodine Over Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis

Hypericum perforatum is a useful plant because of its biological features, such as bactericidal, virucidal, and fungicidal effects. Elimination of periodontal pathogens, including Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, from the oral environment, is important for the stability of periodontal health. Therefore, we aimed to determine the antimicrobial activity of the Hypericum perforatum L. essential oils over these pathogens using cell cultures. The standard and clinical bacterial strains were used in this study. The essential oils extracted from Hypericum perforatum L. flowers were analyzed with gaschromatography/mass spectrometry. The antimicrobial activities of the essential oils along with 0.2 % chlorhexidine, 10 % povidone-iodine, and combinations of essential oils and 0.2 % chlorhexidine, and essential oils and 10 % povidone-iodine were evaluated by measuring the minimum inhibitory concentrations. Essential oils' minimum inhibitory concentration value for clinical A. actinomycetemcomitans strains was significantly lower than that of the povidone-iodine solution (P). However, despite the low minimum inhibitory concentration value of essential oils, when compared to 0.2 % chlorhexidine, there was no statistically significant difference between the agents (P=0.113). For clinical strains of Porphyromonas gingivalis, the essential oils showed a lower minimum inhibitory concentration value compared to chlorhexidine and povidone-iodine. The essential oils combined with chlorhexidine or povidone-iodine showed significantly lower minimum inhibitory concentration value for both strains of Aggregatibacter actinomycetemcomitans (P). With the lower minimum inhibitory concentration values, the essential oils showed strong antimicrobial activity. Moreover, when combined with chlorhexidine or the povidone-iodine, the antimicrobial effect of essential oils on Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis strains increased synergistically.