An evaluation of the action of different root canal irrigants on facultative aerobic-anaerobic, obligate anaerobic, and microaerophilic bacteria.

The aim of this study was to test the effect of different concentrations of sodium hypochlorite, chlorhexidine, and cetrimide on the following bacterial strains: o • Facultative aerobes-anaerobes: Candida albicans ATCC 10231; Enterococcus faecalis ATCC 29212; Escherichia coli ATCC 25 922; Pseudomonas aeruginosa ATCC 27 853; Streptococcus mitis ATCC 9811; Streptococcus mutans ATCC 35668; Streptococcus salivarius ATCC 13419; and Streptococcus sanguis ATCC 10556. • Microaerophiles: Actinobacillus actinomycetem-comitans ATCC 29522. • Obligate anaerobes: Actinomyces odontolyticus ATCC 17929; Fusobacterium nucleatum ATCC 25 586; Porphyromonas gingivalis ATCC 33277; and Prevotella melaninogenica ATCC 25845. Each irrigant was kept in contact with the bacterial species used for the experiment for 10, 20, or 30 min. Results showed that all irrigants had a bacte-ricidal effect on both facultative aerobes-anaerobes and on microaerophilic and obligate anaerobic strains, in all concentrations and even after short periods of contact.