Bactericidal effect of delmopinol on attached and planktonic Streptococcus sanguinis cells

The aim of this investigation was to determine the antibacterial effect of varying concentrations of delmopinol-HCl on attached as well as on planktonic Streptooccus sanguinis cells in vitro. In addition, a possible antiadhesive effect on attached micro-organisms was to be investigated. S. sanguinis cells were allowed to attach to glass surfaces. These as well as planktonic cells were exposed to delmopinol-HCI in concentrations ranging from 0.2% to 0.00005% for 2 min. The percentage of vital bacteria was calculated by means of a fluorescence staining method. Total counts of attached bacteria were performed to determine any possible detaching effect by the delmopinol-HCl. The CFU were determined for the planktonic bacteria. Attached as well as planktonic bacteria showed a marked decrease in vitality following exposure to 0.2% delmopinol-HCl. After exposure to 0.05% this was only the case with the attached microorganisms. The total number of attached bacteria was not reduced by the delmopinol treatment. During initial dental biofilm formation, delmopinol-HCl causes a bactericidal effect when applied in concentrations of 0.05% and higher.