title: Entrococcus faecalis Elimination in Root Canals Using Silver Nanoparticles, Photodynamic Therapy, Diode Laser, or Laser-activated Nanoparticles: An In Vitro Study.
abstract: BACKGROUND
  The aim of this study was to compare the efficacy of silver nanoparticles (AgNPs), an 810-nm diode laser (DL), conventional photodynamic therapy (PDT) with the use of indocyanine green (ICG) photosensitizer, and modified PDT with the use of AgNPs for the disinfection of root canals inoculated with Enterococcus faecalis.
  
  
  METHODS
  The root canals of 65 extracted human single-rooted teeth were prepared, and E. faecalis was incubated in the root canals for 4 weeks. The teeth were then randomly divided into the following 4 experimental groups: the DL group: 810-nm DL irradiation (1 W, 4 times for 10 seconds), the AN group: 5 minutes of irrigation with 5 mL AgNPs (100 ppm), the ICG/DL group: conventional PDT with ICG (1 mg/mL)/810-nm DL (200 mW, 30 seconds), and the AN/ICG/DL group: modified PDT with AgNPs/ICG/810-nm DL (200 mW, 30 seconds). There was also a control group, which consisted of 5 minutes of irrigation with 5 mL 2.5% sodium hypochlorite (n = 9). Samples were obtained from dentin chips before and after the interventions. A reduction in colony count was assessed by counting the colony-forming units.
  
  
  RESULTS
  Significant reductions were noted in E. faecalis colony counts in all groups (P < .05). The greatest reduction in colony count (99.12%) was noted in the AN/ICG/DL group (AgNPs/ICG/810-nm diode laser); however, the differences in this respect between the AN/ICG/DL group and the DL (97.41%), AN (94.42%), and control groups (94.61%) were not significant (P > .05).
  
  
  CONCLUSIONS
  PDT with ICG, an 810-nm diode laser, and AgNPs has the potential to be used as an adjunct for disinfection of the root canal system.
authors.affiliation: Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: f-afkhami@tums.ac.ir.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Afkhami
authors.affiliation: School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Saba
authors.initials: S
authors.lastname: Akbari
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
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003786:Dental Pulp Cavity / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D007208:Indocyanine Green / Q000627:therapeutic use; D007834:Lasers; D053768:Metal Nanoparticles / Q000627:therapeutic use*; D053758:Nanoparticles / Q000528:radiation effects / Q000627:therapeutic use*; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods*; D012834:Silver
chemical_list: D000900:Anti-Bacterial Agents; D017319:Photosensitizing Agents; D012834:Silver; D007208:Indocyanine Green
keywords: Biofilm; Enterococcus faecalis; disinfection; indocyanine green; laser; nanoparticles; root canal