Oda DF, et al. - Researchers performed 3 experiments in this study and analyzed the antimicrobial potential of curcumin photoactivated by a LED curing light (blueLED) in the presence of carbopol gel. In Experiment 1, they observed no improvement in the intensity of LED light transmission with the use of carbopol gel along the root canal. In Experiment 2, a significant decline in bacterial viability was noticed in the following sequence: positive control < only LED curing light < only curcumin < curcumin + LED curing light=standard PDT. In Experiment 3, they recorded positive control=curcumin + LED curing light ≤ curcumin + gel + LED curing light ≤ standard PDT. Overall, they concluded insignificant support of carbopol gel use in transmission of LED light along the root canal. Less bacterial killing was also observed when carbopol gel was used in endodontic PDT.