Background: The main bacterial aetiological agents in caries formation are the α-haemolytic Streptococcal species Streptococcus mutans, which has been found to be the initiator of most dental caries. The leaves of Camellia sinensis known as green tea, has properties, such as antibacterial and anti-cariogenic. Epigallocatechin-3-gallate (EGCG) one of the most abundant catechins found in green tea is known to contribute to these effects.
Aim: To evaluate the antibacterial effect of green tea catechins namely EGCG on S. mutans with two different methods at different concentrations.
Objectives: 1) To assess the antimicrobial efficacy of EGCG by disc diffusion test at concentrations of 100, 75, and 50 μg/mL. 2) To assess the antimicrobial efficacy of EGCG by Minimum inhibitory concentration (MIC) test at concentrations ranging from 0.2 to 100 μg/mL.
Methodology: Commercially available purest form of green tea polyphenol EGCG was used in the study. Disc diffusion test on agar medium and MIC test was used to determine the susceptibility of the S. mutans to green tea catechins EGCG.
Results: The results of the agar well diffusion method showed that the EGCG extract has shown zones of inhibition against S. mutans at concentrations of 100 μg/mL (28.67 mm), 75 μg/mL (15.33 mm), 50 μg/mL (10.33 mm) while that of MIC test of EGCG extract of concentrations ranging from 0.2 to 100 μg/mL against S. mutans shows that the mean MIC value was 1.07.
Conclusion: Catechins in the tea are potentially anti-cariogenic agents which can reduce bacterial presence in the oral cavity and have the potential to be further used for the preparation of dentifrice and mouthwash.
Keywords: Camellia sinensis; Streptococcus mutans; caries; dental decay; epigallocatechin-3-gallate.