The role of bacteria in root canal system infection has been repeatedly demonstrated over time. The root canals and periapical tissues contain a variety of kinds of bacteria, including aerobic, facultative anaerobes, and anaerobic bacteria. In order for endodontic therapy to be successful, the microbial burden must be kept to a minimum and must not be allowed to recolonize the canal system. The thorough application of irrigants and intracanal medications is essential to the disinfection process. In between appointments, intracanal medications effectively remove pathogens. Therefore, it is essential to comprehend the aspects that influence an intracanal medication's effect as well as the factors that assist in selecting the appropriate one based on the case.