The antibacterial and anti-staining properties of the novel anti-adherent agent M239, 144 alone and in combination with chlorhexidine

The anti-adherent agent M239,144 has been shown to reduce the adhesion of S. sanguis strains to saliva-coated hydroxyapatite by 27-94%. The purpose of this study was to determine any antibacterial properties of M239,144 which might inhibit replication of the organisms which do adhere and to determine whether M239,144 interferes with the antibacterial properties of the antiseptic agent chlorhexidine. Maximum inhibitory dilutions (MIDs) were calculated using both broth and agar methods. 0.1% M239,144 displayed no antibacterial activity against S. oralis NCTC 7864 or S. sanguis NCTC 7863 using the broth dilution method and had no antibacterial activity against a range of plaque-forming organisms using the agar dilution method. The anti-bacterial activity of chlorhexidine against four of five oral plaque-forming species was reduced by 0.1% M239,144. The effect of a novel anti-adherent agent, MK239,144, on chlorhexidine staining was assessed in an in vitro model. 1% M239,144 completely prevented chlorhexidine staining at concentrations from 0.0002% to 0.2%. M239,144/chlorhexidine formulations show potential for a non-staining anti-plaque mouthwash.