Back to nature is the concept that most of workers in the medical and dental fields are searching for nowadays. Coconut oil and Nigella sativa are used to treat a wide range of health problems.
In the dental field they had been documented to possess an inhibitory effect on some oral cariogenic microorganisms. Aim: Thus, the aim of the current study was to evaluate the antibacterial effect of Coconut and Nigella Sativa oils on Streptococcus mutans, Lactobacilli and Candida albicans as a natural mean for prophylaxis against dental caries.
Materials and methods: Two herbal oils (Coconut and Nigella sativa) and Chlorhexidine gluconate 0.2% as a positive control were used in this study. Streptococcus mutans, Lactobacilli, and Candida albicans were isolated and incubated. Growth inhibitory effect of the tested materials was evaluated by direct contact method for each microorganism separately by adding 0.5 ml. of the tested material to each organism in a sterile tube and incubated at 37°C aerobically for Streptococcus mutans and Candida albicans and anaerobically for Lactobacilli then the tested microorganisms were spread on specific media. The count of the microorganisms was expressed as CFU/plate and recorded after 2 and 24 hours.
Results: Coconut oil showed marked % of reduction on both SM and Candida albiacans
(89.3 % and 87.3 %) after 24 hours contact period. Nigella Sativa oil showed marked reduction on SM after 2 hours only (68.33%) with no effect on Candida albicans. Both oils had no effect on LB. The highest % of reduction of all tested microorganisms was recorded with Chlorhexidine.
Conclusions: Coconut oil has a great inhibitory effect on both SM and Candida albicans with this effect extending by time, but no effect on LB. Nigella sativa oil has an inhibitory effect on SM over a short contact period, but this effect decreased and even vanished by time, but it has no effect on neither Candida albicans nor LB. Chlorhexidine showed the most superior results on all tested microorganisms.