title: The in vitro effect of antimicrobial photodynamic therapy with indocyanine green on Enterococcus faecalis: Influence of a washing vs non-washing procedure.
abstract: BACKGROUND
  The purpose of this study was to evaluate the in vitro effect of washing and non-washing of indocyanine green (ICG) as photosensitizer (PS) on bacterial count, biofilm formation, development and degradation of Enterococcus faecalis.
  
  
  METHODS
  The anti-bacterial, anti-biofilm formation, anti-biofilm development and biofilm degradation of anti-microbial photodynamic therapy (aPDT) against E. faecalis was determined at concentrations of 3 to 2000μg/mL of ICG, subject to 18J/cm2dose of diode laser (808nm) in washing and non-washing producers. Bacterial viability measurements and biofilm assays were evaluated by broth microdilution method and crystal violet assays, respectively.
  
  
  RESULTS
  ICG-mediated aPDT, using 25 to 2000μg/mL and 50 to 2000μg/mL showed significant reduction in E. faecalis growth when compared to the control in non-washing and washing producers, respectively (P<0.05). Also, ICG-mediated aPDT showed a significantly inhibitory effect on biofilm formation of E. faecalis in concentration of 6 to 2000μg/mL and 100 to 2000μg/mL in non-washing and washing groups (P<0.05). The biofilm development was inhibited by concentrations of 12 to 2000μg/mL and 100 to 2000μg/mL in non-washing and washing groups. The biofilm degradation increased from concentrations of 12 to 2000μg/mL and 250 to 2000μg/mL in non-washing and washing groups, respectively.
  
  
  CONCLUSIONS
  This study shows that the application of ICG should be accompanied by laser irradiation without being washed out to achieve better result for bacterial count reduction and anti-biofilm effects.
authors.affiliation: Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
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: Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Steven
authors.initials: S
authors.lastname: Parker
authors.affiliation: Dental Biomaterials Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: shahabis@sina.tums.ac.ir.
authors.forename: Sima
authors.initials: S
authors.lastname: Shahabi
authors.affiliation: Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dental 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: D058491:Bacterial Load / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004203:Disinfection / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D007208:Indocyanine Green / Q000008:administration & dosage*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D017319:Photosensitizing Agents; D007208:Indocyanine Green
keywords: Biofilm degradation; Biofilm development; Biofilm formation; Endodontic infection; Enterococcus faecalis; Indocyanine green