Yoshiko Masuda1,2, Hiroshi Sakagami2, Masashi Horiike3, Hiroshi Kadokura3, Takahide Yamasaki3, Perry R Klokkevold4, Henry H Takei5, Satoshi Yokose3. 1. Division of Endodontics and Operative Dentistry, Department of Restorative and Biomaterials Sciences, School of Dentistry, Meikai University, Saitama, Japan yoshik@dent.meikai.ac.jp. 2. Meikai University Research Institute of Odontology (M-RIO), Saitama, Japan. 3. Division of Endodontics and Operative Dentistry, Department of Restorative and Biomaterials Sciences, School of Dentistry, Meikai University, Saitama, Japan. 4. Section of Postgraduate Periodontics and Implant Surgery, School of Dentistry, University California, Los Angeles, CA, U.S.A. 5. Section of Periodontics, School of Dentistry, University California, Los Angeles, CA, U.S.A.
Abstract
BACKGROUND/AIM: Enterococcus faecalis is responsible for most cases of endodontic treatment failure. Despite various conventional disinfection methods, root canals are not completely free of microorganisms. Photodynamic therapy (PDT) is a new antimicrobial strategy that involves the use of a non-toxic photosensitizer (PS) and a light source. The aim of this study was to evaluate the antimicrobial effect of PDT using diode laser and pyoktanin blue (PB) and confirm the nontoxicity of PB as a PS. MATERIALS AND METHODS: Laser irradiation with an output power of 3 W was performed with PB as the PS to a bacterial solution containing E. faecalis. Then, the number of colony-forming units was counted. PB cytotoxicity was also assessed by the MTT assay. RESULTS: E. faecalis counts were reduced after laser irradiation, laser irradiation with PB, or the combination thereof compared to the control, non-irradiation or water. The 50% cytotoxic concentration value for adult human dermal fibroblasts incubated with PB for 1 min was 108 μg/ml. CONCLUSION: Diode laser irradiation in combination with PB as the PS is efficacious for the elimination of E. faecalis without toxic effects to human dermal fibroblasts. This strategy might be useful for root canal irrigants. Copyright
BACKGROUND/AIM: Enterococcus faecalis is responsible for most cases of endodontic treatment failure. Despite various conventional disinfection methods, root canals are not completely free of microorganisms. Photodynamic therapy (PDT) is a new antimicrobial strategy that involves the use of a non-toxic photosensitizer (PS) and a light source. The aim of this study was to evaluate the antimicrobial effect of PDT using diode laser and pyoktanin blue (PB) and confirm the nontoxicity of PB as a PS. MATERIALS AND METHODS: Laser irradiation with an output power of 3 W was performed with PB as the PS to a bacterial solution containing E. faecalis. Then, the number of colony-forming units was counted. PBcytotoxicity was also assessed by the MTT assay. RESULTS:E. faecalis counts were reduced after laser irradiation, laser irradiation with PB, or the combination thereof compared to the control, non-irradiation or water. The 50% cytotoxic concentration value for adult human dermal fibroblasts incubated with PB for 1 min was 108 μg/ml. CONCLUSION: Diode laser irradiation in combination with PB as the PS is efficacious for the elimination of E. faecalis without toxic effects to human dermal fibroblasts. This strategy might be useful for root canal irrigants. Copyright