Comparison of the Antimicrobial Effect of Chlorine Dioxide, Sodium Hypochlorite and Chlorhexidine, on Bacteria Isolated from the Root Canal

Aim: To compare the antimicrobial capacity of Chlorine Dioxide (ClO2), Sodium Hypochlorite (NaOCl) and Chlorhexidine (CHX) in microorganisms isolated from persistent apical periodontitis and ATCC strains. Materials and methods: The microorganisms included were analyzed by Minimum Inhibitory Concentration (MIC): 50 µl of saline solution and 100 µl of Chlorine Dioxide 0.25%, Sodium Hypochlorite 1% and Chlorhexidine 2% were used to make the following dilutions of 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128, 1:256, 1:512, 1:1024 and test them with the following microorganisms, E. faecalis from root canal and S. viridans, anginosus group from the alveolus, in adittion, Escherichia coli ATCC and Staphylococcus aureus ATCC were included to observe bacterial growth after 18h of incubation. Results: NaOCl inhibited the microorganisms in all the dilutions, the ClO2 showed bacterial growth in dilution 1:128, CHX1:8, in E. faecalis, S. viridans, anginosus group, ClO2:1:32, CHX:1:8, Escherichia coli ATCC ClO2:1:32, CHX:1:128, Staphylococcus aureus ATCC ClO2:1:64 and CHX:1:256. Conclusion: NaOCl was the chemical agent that inhibited all the strains evaluated, followed by ClO2 and Chlorhexidine 2% needed higher concentrations for the eradication of the analyzed strains.