The Effect of Variable Energy Input from a Novel Light Source on the Photoactivated Bactericidal Action of Toluidine Blue O on Streptococcus mutans

作者：Jill A. Williams, Gavin J. Pearson, M. J. Colles, Michael James Wilson · 发表于：Caries Research · 年份：2003 · DOI：10.1159/000070443 · 被引用次数：90 · 研究领域：Photodynamic Therapy Research Studies、Photoacoustic and Ultrasonic Imaging、Ocular Infections and Treatments

Although the combination of toluidine blue O (TBO) dye and laser light at a wavelength of 633 nm has a bactericidal effect, light from laboratory lasers can only be directed externally at a bacterial colony or suspension. In this study a novel delivery system guided the laser light to an 800-micrometer diameter spherical tip (an isotropic tip) from which light radiated producing a uniform sphere of light within the colony or suspension. The system was highly effective in killing TBO-treated Streptococcus mutans NCTC 10449 in stirred planktonic suspension, killing at least 10(9 )cfu/ml. Antibacterial action increased as the delivered energy dose increased. Energy doses of 1.8 J or more produced 100% kills and log reductions of 8-10 cfu/ml. Neither TBO dye nor light alone had a significant antibacterial effect under the experimental conditions used. The existence of a threshold energy, i.e. a minimum energy required before bactericidal action occurred, could not be demonstrated.