Recurrent caries can be prevented in large part by the antibacterial activity of restorative materials. This study aims at evaluating and comparing the antimicrobial activity and compressive strength of thyme-modified Glass ionomer cement with conventional Glass ionomer cement. The thyme extract was prepared from the dried thyme leaves. By combining an extract with the powder and liquid of traditional GIC, modified GIC was created in PowderGIC, Extract, LiquidGIC ratio of 2:1:1, 3:1:2 and 3:2:1 and labeled as Group I, Group II, Group III respectively, and Group IV as control (unmodified GIC). The antibacterial effectiveness of modified and unmodified (control)GIC was examined using standard strains of S. mutans and Lactobacillus.MIC assay was done for all the groups; the incubation was done under suitable conditions for varied time intervals (1h, 2h, 3h, 4h). Using cylindrical molds, compressive strength was assessed in accordance with ISO 9917-1:2007. To get the compressive strength values in MPa, the greatest force that the specimen could withstand before it fractured was noted. The results proved that, against S.mutans, all modified groups showed the highest antimicrobial activity without compromising strength when compared with the control group (p>0.05)and against Lactobacillus and no statistically significant difference between modified and control groups (p>0.05) was seen. Thus, thyme-modified glass ionomer cement has enhanced antimicrobial activity when compared to conventional glass ionomer cement.
