Antibacterial effect of cardamom and black tea aqueous extract on mutans streptococci in comparison to chlorhexidine (in vitro study)


Background: Antimicrobial agents have been considered as having potential for the prevention of dental caries. Thisstudy aimed to test the effect of different concentrations of cardamom and black tea extracts on the sensitivity andgrowth of salivary mutans streptococci in comparison to chlorhexidine gluconate (0.2%) in vitro.Materials and methods: In this study. Mutans streptococci were isolated from saliva of 34 healthy people (agedbetween 22-40yrs). The bacteria was isolated, purifiedand diagnosed according to morphologicalcharacteristic andbiochemical tests. Aqueous extracts of cardamom and black tea were prepared. Different concentrations ofextracts were prepared and estimated in gm/ 100ml deionized water. The agar diffusion technique was used todetermine the antibacterial activity of cardamom and tea extracts in which the inhibition of bacteria growth bydifferent concentrations of extracts was measured by diameter of inhibition zone in millimeter. The viable count wasmeasured in different concentrations for both types of extracts on comparison to chlorhexidine 0.2%.Results: The result showed that the mutans streptococci is more sensitive to tea extract than cardamom one, wherethe mean value of diameter of inhibition zone was higher by tea extract than cardamom type in all concentrationsand chlorohexidine0.2% is more effective than both extracts. For viable count no statistical significant differencebetween two extract types at concentration of 40% but there are a high statistical significant difference for otherconcentrations, where the chlorhexidine is moreeffective than tea type and the last one is more effective thancardamom type with p value 0.05 .Conclusions: Cardamom and black tea have antibacterial effect against Mutans streptococci; the accused factorof dental caries.