title: Photo-activated disinfection based on indocyanine green against cell viability and biofilm formation of Porphyromonas gingivalis.
abstract: BACKGROUND
  Photo-activated disinfection (PAD) is a novel treatment approach, in which bacteria in the root canal system may be exposed to sub-lethal doses of PAD. Such exposure can affect bacterial survival and virulence features, such as biofilm formation ability. The aim of this study was to evaluate the effects of sub-lethal doses of PAD (sPAD) using indocyanine green (ICG) on load and biofilm formation ability of Porphyromonas gingivalis as an anaerobic bacterium associated with endodontic infection.
  
  
  METHODS
  The anti-bacterial and anti-biofilm potential of sPAD against P. gingivalis at sub-lethal doses of ICG as a photosensitizer and using 810nm wavelength of diode laser light via colony forming unit and crystal violet assays, respectively, was determined.
  
  
  RESULTS
  High concentrations of ICG and light irradiation time significantly reduced bacteria. High doses of sPAD markedly reduced the number of bacteria and the formation of biofilm, up to 30.4% and 25.1%, respectively.
  
  
  CONCLUSIONS
  High doses of sPAD affected cell viability and the biofilm formation ability of P. gingivalis; lower doses did not. Thus, selection of appropriate PAD dosage should be considered for the successful treatment of endodontic in vivo.
authors.affiliation: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Pourhajibagher
authors.affiliation: Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
authors.affiliation: Private practice, Tehran, Iran.
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Ghorbanzadeh
authors.affiliation: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: abahador@sina.tums.ac.ir.
authors.forename: Abbas
authors.initials: A
authors.lastname: Bahador
mesh_terms: D018441:Biofilms / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004203:Disinfection / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D007208:Indocyanine Green / Q000008:administration & dosage / Q000494:pharmacology*; D054023:Lasers, Semiconductor; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000494:pharmacology*; D016966:Porphyromonas gingivalis / Q000187:drug effects*
chemical_list: D017319:Photosensitizing Agents; D007208:Indocyanine Green
keywords: Anti-biofilm; Anti-microbial effect; Endodontic infection; Indocyanine green; Photo-activated disinfection; Porphyromonas gingivalis; Sub-lethal dose