Killing of Streptococcus sanguis in biofilms using a light-activated antimicrobial agent

Abstract

The aim of this study was to determine whether Streptococcus sanguis, when in a biofilm, could be killed using a light-activated antimicrobial agent. BiofUms were grown on hydroxyapatite, irradiated with up to 12.2 J of light from a gallium aluminium arsenide laser in the presence of aluminium disulphonated phthalocyanine (AlPcS₂) and survivors enumerated. No significant decrease in the viable count was found when either the AlPcS₂ or the laser light was used alone. There was a light dose related decrease in the viable counts of irradiated AJPcS₂ treated biofims. No viable streptococci were detectable following irradiation with 12.2 J of laser light.