In Vitro Testing of Susceptibility to Endodontic Irrigants and Disinfectants of Bacterial Strains Isolated from Chronic Apical Periodontitis

The key factor in the production of pulp and periapical inflammation is represented by the presence of bacteria in the root canal system and the outcoming toxins. Bacterial biofilm is identifiable in the various areas of the endodontic space, but due to the complexity of the internal anatomy of the root canal, bacteria removing is yet difficult to obtain, a particularly important step for treatment success representing the medication choice. The purpose of this study was to determine the sensitivity spectrum of microbial strains isolated from chronic apical periodontitis teeth microbiota to different antimicrobials used in the chemomechanical disinfection stages: irrigants, local antiseptics, antibiotics.Material and Methods. Following tooth extractions, there were taken evidence of apical lesions chronic from twenty-nine patients; the identified microbial strains were identified based on the colony character, Gram stain, conventional biochemical tests and API kits. The isolated microbial strains were tested for susceptibility to different antibiotics and antiseptic substances, as well as irrigants of dental usage by using an adpated diffusion method. Results: Our study revealed that some of the analyzed strains were totally susceptible to conventional antiseptics. Analysis of irrigants inhibiton action and medicinal dressings currently used in endodontic practice (sodium hypochlorite 2.5% and 3%, 5.25%, 2% chlorhexidine gel and solution, EDTA) showed that strains isolated from chronic apical periodontitis were generally susceptible to their action. Disinfectants presented a lower level of antimicrobial effect in comparisson to that observed within antiseptics.Conclusions: Different types of microbial agents action is generally different depending on their type (antiseptics, chelating agents, irrigants, calcium hydroxide). Antiseptics presented the most efficient antimicrobial action. It was found that various antimicrobial agents had variable effects on different tested strains and generally, antiseptics exhibited a superior antimicrobial effect than the tested disinfectants.