155ANTIMICROBIAL EFFICACY OF STEVIA REBAUDIANA ON STREPTOCOCCUS MUTANS USING THREE DIFFERENT SOLVENTS – AN INVITRO COMPARATIVE STUDYThe objective of this study is to compare and evaluate invitro antimicrobial efficacy of Stevia rebaudiana on streptococcus mutans using 3 different solvents (Ethanol, petroleum ether and Acetone). Stevia rebaudiana leaves are to be washed; air dried for 7-8 days, Grounded into powder and 100 g weighed powder is to be taken for extraction in the flask of soxhelet apparatus using ethanol (100%), petroleum ether (100%) and acetone (100%) as solvents.All the above extracts are to be filtered using whatman’s no: 1 filter paper and the filtrates are then evaporated to dryness in a rotary evaporator. The extracts are to be labelled and stored in sterile screw capped bottle under 200c until further analysis. Determination of minimum inhibitory concentration (MIC): Plate dilution method, is followed to determine (MIC). The Medium used is Nutrient Agar. The seeded plates are incubated at 370c for 48 hours and the growth is noted down for different extracts separately. All the experiments are done in triplicates and positive, negative controls are run parallel along with the sample analysis. The results obtained from this study was done measuring the inhibition zone diameter (IZD) and evaluating the means value, it was observed that Stevia rebaudiana extracted with ethanol had higher antimicrobial property on streptococcus mutans followed by petroleum ether and acetone. The statistical value obtained [ Table 2] shows that extracts of stevia in ethanol performed better after 48 hours [34 ± 0.40 ] when compared to petroleum ether [30 ± 0 ] and acetone [25.33 ± 0.40]. Within the limitations of this study, it can be concluded that Stevia rebaudiana extracted with ethanol had better antimicrobial property than petroleum ether and acetone against streptococcus mutans.ashik0999@gmail.comResearch632016Stevia rebaudiana,inhibition zone,streptococcus mutans,antimicrobial propertyYadav Chakravarthy,Ashik HussainDepartment of Endodontics, Vinayaka Mission Sankarachariyar Dental College, Salem, Tamil Nadu, India,Department of Endodontics, Vinayaka Mission Sankarachariyar Dental College, Salem, Tamil Nadu, India