Efficacy of antimicrobial photodynamic therapy with Rose Bengal and blue light against cariogenic bacteria.

OBJECTIVE:We evaluated the effect of antimicrobial photodynamic therapy (a-PDT) with Rose Bengal and blue light LED on bacteria that initiate and promote dental caries. DESIGN:Colony forming units of Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis, and Lactobacillus salivarius under planktonic and biofilm conditions were counted after a-PDT treatment using Rose Bengal and blue light LED. In addition, cariogenic bacteria from saliva and dental plaques from ten volunteers were used for evaluation of a-PDT treatment. RESULTS:We found that a-PDT using Rose Bengal at > 10 μg/mL had antimicrobial effects on oral Gram-positive S. mutans, S. sobrinus, S. sanguinis, and L. salivarius under both planktonic and biofilm conditions. The effect was also observed for cariogenic bacteria that formed biofilms containing water-insoluble glucans, through which the bacteria are firmly attached to the tooth surface. Moreover, a-PDT led to a marked reduction in cariogenic bacteria in saliva and dental plaques. CONCLUSION:a-PDT could be a useful approach for controlling dental caries in dental surgery.