In Vitro Anti-Cariogenic Plaque Effects of Essential Oils Extracted from Culinary Herbs.

INTRODUCTION

Cariogenic bacteria including mutans streptococci and lactobacilli are partly but significantly involved in dental caries development. An effective prevention strategy against dental caries is to decrease the accumulation of this microbiota either in planktonic or in biofilm form.

AIM

To examine the antimicrobial and anti-plaque effects of some culinary herbs (spices), so the herbs are plausibly used as alternative and effective herbal plaque control supplements to promote good oral health.

MATERIALS AND METHODS

Essential oils extracted from sweet basil , cinnamon bark , sweet fennel , kaffir lime , black pepper , peppermint , and spearmint were primarily examined for their antimicrobial activities against the cariogenic bacteria KPSK2 and using the agar disk diffusion and broth microdilution methods, respectively. These essential oils were then analysed for anti-plaque effects (retardation of biofilm formation and reduction of the in vitro established biofilm). This experimental study was performed at the Department of Oral Microbiology, Faculty of Dentistry, Mahidol University during June 2015 till August 2016.

RESULTS

All selected essential oils showed different degrees of antimicrobial activity against the planktonic form of both cariogenic bacteria. Cinnamon bark essential oil expressed the strongest inhibitory effect against {MIC of 0.08% (v/v)} and {MIC of 0.16% (v/v)}, whereas the weakest effect was found in kaffir lime essential oil {MIC values of 2.5% and 5.0% (v/v) for and , respectively}. Up to 80% of biofilm was retarded to form on the substratum primed with these spice essential oils, especially cinnamon oil. The preventive effect of these oils was in dose- and exposure time-dependent manners. For reductive effect against the 24-hour pre-established biofilm, at least 50% of the biofilm mass was reduced when the biofilm was treated with each essential oil at the MIC for an hour. The reductive effect against the in vitro established biofilm of these culinary herb essential oils only depended on the exposure time.

CONCLUSION

Cinnamon and sweet basil essential oils with impressive in vitro anti-cariogenic bacteria and anti-plaque effects may be proposed as alternative and effective supplements to promote oral health status.