title: Bactericidal effect of visible light in the presence of erythrosine on Porphyromonas gingivalis and Fusobacterium nucleatum compared with diode laser, an in vitro study.
abstract: OBJECTIVE
  Recently, photodynamic therapy (PDT) has been introduced as a new modality in oral bacterial decontamination. Besides, the ability of laser irradiation in the presence of photosensitizing agent to lethal effect on oral bacteria is well documented. Current research aims to evaluate the effect of photodynamic killing of visible blue light in the presence of plaque disclosing agent erythrosine as photosensitizer on Porphyromonas gingivalis associated with periodontal bone loss and Fusobacterium nucleatum associated with soft tissue inflammation, comparing with the near-infrared diode laser.
  
  
  METHODS
  Standard suspension of P. gingivalis and F. nucleatum were exposed to Light Emitting Diode (LED) (440-480 nm) used to photopolymerize composite resine dental restoration in combination with erythrosine (22 µm) up to 5 minutes. Bacterial sample were also exposed to a near-infrared diode laser (wavelength, 830 nm), using identical irradiation parameters for comparison. Bacterial samples from each treatment groups (radiation-only group, erythrosine-only group and light or laser with erythrosine group) were subcultured onto the surface of agar plates. Survival of these bacteria was determined by counting the number of colony forming units (CFU) after incubation.
  
  
  RESULTS
  Exposure to visible blue light and diode laser in conjugation with erythrosine significantly reduced both species examined viability, whereas erythrosine-treated samples exposed to visible light suggested a statically meaningful differences comparing to diode laser. In addition, bactericidal effect of visible light or diode laser alone on P. gingivalis as black-pigmented bacteria possess endogenous porphyrins was noticeably.
  
  
  CONCLUSIONS
  Our result suggested that visible blue light source in the presence of plaque disclosing agent erythrosine could can be consider as potential approach of PDT to kill the main gram-negative periodontal pathogens. From a clinical standpoint, this regimen could be established as an additional minimally invasive antibacterial treatment of plaque induced periodontal pathologies.
authors.affiliation: Department of Periodontics, School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ghanbari
authors.initials: G
authors.lastname: Habiboallah
authors.affiliation: School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zakeri
authors.initials: Z
authors.lastname: Mahdi
authors.affiliation: Department of Medical Bacteriology & Virology, Emam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Naderi Nasab
authors.initials: NN
authors.lastname: Mahbobeh
authors.affiliation: School of Dentistry, Shahed University, Tehran, Iran.
authors.forename: Zareian Jahromi
authors.initials: ZJ
authors.lastname: Mina
authors.affiliation: School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Faghihi
authors.initials: F
authors.lastname: Sina
authors.affiliation: School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zakeri
authors.initials: Z
authors.lastname: Majid
keywords: Diode laser; Erythrosine; Fusobacterium nucleatum; Porphyromonas gingivalis; visible light