The antimicrobial activity of photodynamic therapy against Streptococci species in dental biofilm using different photosensitizers: an in vitro study

The purpose of the present study was evaluating in vitro the effect of Photodynamic Therapy (PDT) with application of various types of photosensitizing agents on streptococci strains in dental biofilm. The bactericidal effect of applying photosensitizing substances and subsequent irradiation with LED 625-635 nm was assessed by measuring the reduction areas of microorganism growth within 24 hours after applying PDT. The data obtained in the research conducted in vitro showed that applying the PDT method with anthocyanin extract as photosensitizing substance and a catalyst ensures a total destruction of cariogenic microorganisms - Streptococcus mutans, Streptococcus mitis, Streptococcus gordonii, Streptococcus sobrinus, etc. The data obtained justify the necessity of subsequent research in clinical and in vivo conditions in the field of using anthocyanin extract as photosensitizing substance in PDT. The application of PDT provides new opportunities in elaborating efficient methods for caries prevention.