title: Lethal effect of blue light-activated hydrogen peroxide, curcumin and erythrosine as potential oral photosensitizers on the viability of Porphyromonas gingivalis and Fusobacterium nucleatum.
abstract: OBJECTIVE
  Recently, photodynamic therapy (PDT) has been introduced as a new modality in oral bacterial decontamination. Current research aims to evaluate the effect of photodynamic killing of visible blue light in the presence of hydrogen peroxide, curcumin and erythrosine as potential oral photosensitizers on Porphyromonas gingivalis associated with periodontal bone loss and Fusobacterium nucleatum associated with soft tissue inflammation.
  
  
  METHODS
  Standard suspension of P. gingivalis and F. nucleatum were exposed to Light Emitting Diode (LED) (440-480 nm) in combination with erythrosine (22 µm), curcumin (60 µM) and hydrogen peroxide (0.3 mM) for 5 min. Bacterial samples from each treatment groups (radiation-only group, photosensitizer-only group and blue light-activated photosensitizer 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
  RESULTS for antibacterial assays on P. gingivalis confirmed that curcumin, Hydrogen peroxide and erythrosine alone exerted a moderate bactericidal effect which enhanced noticeably in conjugation with visible light. The survival rate of P. gingivalis reached zero present when the suspension exposed to blue light-activated curcumin and hydrogen peroxide for 2 min. Besides, curcumin exerted a remarkable antibacterial activity against F. nucleatum in comparison with erythrosine and hydrogen peroxide (P=0.00). Furthermore, the bactericidal effect of visible light alone on P. gingivalis as black-pigmented bacteria was significant.
  
  
  CONCLUSIONS
  Our result suggested that visible blue light in the presence of erythrosine, curcumin and hydrogen peroxide would be consider as a potential approach of PDT to kill the main gramnegative 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: 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 Periodontics, School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ghanbari
authors.initials: G
authors.lastname: Habiboallh
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: Zakeri
authors.initials: Z
authors.lastname: Majid
authors.affiliation: Department of Restorative, School of Dentistry and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Arjmand
authors.initials: A
authors.lastname: Nooshin
keywords: Curcumin; Erythrosine; Hydrogen peroxide; Oral antibacterial activity; Periopathogenic bacteria; Visible blue light