Antimicrobial effect of fluorides on Bacteroides melaninogenicus subspecies and Bacteroides asaccharolyticus.

This study was undertaken to determine whether the suspected periodontopathogens Bacteroides melaninogenicus ss melaninogenicus and intermedius and Bacteroides asaccharolyticus are killed by clinically used topical fluorides. The viability of each organism was examined after exposure to three fluoride compounds, stannous (SnF2), acidulated phosphate (APF), and neutral sodium (NaF), for 1 and 8 h. Stannous fluoride was found to be effective at lowest fluoride concentrations with APF next in effectiveness. NaF required the highest concentrations of fluoride to kill test organisms. Longer exposure times were found to be more effective at lower concentrations. Data obtained in this study with gram-negative organisms support and extend previous information regarding the antibacterial effect of fluorides against gram-positive periodontopathogens.