Effects of photodynamic therapy on the activity and structure of the dental plaque biofilms / 国际生物医学工程杂志

ABSTRACT

ObjectiveTo investigate the effects of photodynamic therapy(PDT) on the activity and structure of the dental plaque biofilm formed by the main cariogenic bacteria.MethodsS.mutans,S.sangius,L.acidophilus and A.viscosus were chosen as the experimental bacteria to establish dental plaque biofilm model.They were separated into three groupsgroup of PDT、group of chlorhexidine and group of normal saline.The influence of the dental plaque biofilms was observed according to plate counting of bacteria method.The changes in the structure of biofilms after PDT were analyzed by means of confocal laser scanning microscopy.Results Compared to normal saline group,chlorhexidine cariogenic bacteria (CFU/ml) in plaque biofilms significantly reduced (P＜0.05),with the bactericidal rate 57.84％.After PDT treatment against artificial caries model,the number of cariogenic bacteria (CFU/ml) in plaque biofilms reduced more significantly (P＜0.05),the bactericidal rate up to 94.92％,and the structure of dental plaque biofilns changed evidently.ConclusionPDT is an effective method in eliminate cariogenic bacteria of dental plaque biofilms and to destroy the integrity of dental plaque biofilms,and it is a promising method for elimination of dental plaque and prevention of caries.