Objectives: This study focuses on examining the inhibitory activity of Cinnamomum aromaticum, Citrus paradisi Pimpinella anisum and Pinus sylvestris essential oils against caries-related microorganisms.
Methods: Streptococcus mutans KPSK2, clinincal isolated Lactobacillus casei and Candida albicans ATCC 10231 were caries related microbes selected for this study. Each essential oil was primarily screened for its inhibitory activity against those tested microorganisms by agar disk diffusion. The one (s) displaying inhibition zone was further evaluated for both minimum inhibitory concentration (MIC) and minimum cidal concentration (MCC) by micro-broth dilution method and cultivation.
Results: All tested essential oils demonstrated inhibition zone against the caries-related microorganisms. Moreover, these essential oils expressed different degrees of antimicrobial activity. Their MIC and MCC values were in the range of 0.313 to >100 µl/ml. Against all tested microbes, C. aromaticum essential oil demonstrated the lowest MIC and MCC values, and then followed by P. sylvestris, P. anisum and C. paradisi oils, respectively.
Conclusions: C. aromaticum essential oil contained the strongest antimicrobial efficacy against caries-related microbes, among other tested oils including P. sylvestris, P. anisum and C. paradisi.