Antimicrobial activity of different concentrations of NaOCl and chlorhexidine using a contact test

ABSTRACT

The purpose of this study was to analyze the in vitro antimicrobial activity of sodium hypochlorite (1 percent and 5 percent) and chlorhexidine (0.12 percent, 0.5 percent and 1 percent). Bacterial samples (ATCC) of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Porphyromonas gingivalis and Fusobacterium nucleatum were submitted to a contact test. Solutions were evaluated at different time intervals immediately, 5 min, 15 min, and 30 min after contact and repeated 10 times. The results of the contact test showed that 0.12 percent chlorhexidine did not eliminate E. faecalis at any time interval, while 0.5 percent and 1 percent chlorhexidine and 1 percent and 5 percent sodium hypochlorite did. These results permit us to conclude that to obtain better antimicrobial activity, chlorhexidine in a concentration greater than 0.12 percent should be used