title: Antimicrobial effect of photodynamic therapy using high-power blue light-emitting diode and red-dye agent on Porphyromonas gingivalis.
abstract: OBJECTIVE
  Antimicrobial photodynamic therapy (a-PDT) using a combination of red-colored laser/light-emitting diode (LED) and blue dye has been employed for periodontal therapy and the antimicrobial effect seems promising. Blue light, which has favorable wavelength properties, would be more effective as a light source for a-PDT because blue light itself possesses an antimicrobial effect. This study aimed to investigate the effect of a-PDT using a novel combination of high-power blue LED and red-dye agent on Porphyromonas gingivalis in vitro.
  
  
  METHODS
  Porphyromonas gingivalis ATCC 33277 suspension was irradiated with blue LED (BL) (425-470 nm) or red LED (RL) (625-635 nm) at 30-90 J/cm(2) , or was mixed with erythrosine (ER), phloxine B (PB) or rose bengal (RB) with or without BL irradiation (30 J/cm(2) ). RL (30 J/cm(2) ) in combination with toluidine blue was employed as positive control. All the suspensions of P. gingivalis were serially diluted, plated and incubated anaerobically, and the numbers of colony-forming units (CFUs) were counted on day 7.
  
  
  RESULTS
  BL irradiation at 60 and 90 J/cm(2) demonstrated a significant reduction in the numbers of CFUs. ER, PB and RB solutions at 160 μg/mL showed almost no or only a minimal reduction in the numbers of CFUs. BL at 30 J/cm(2) combined with ER, PB or RB at 160 μg/mL resulted in a log reduction of 0.9, 1.0 and 7.1, respectively, in the numbers of CFUs; 30 J/cm(2) BL with RB at 1.6, 16 and 160 μg/mL demonstrated a log reduction of 6.3, 8.0 and 5.5, respectively; and a log reduction of 5.2 was obtained after 30 J/cm(2) RL with 16 μg/mL TB.
  
  
  CONCLUSIONS
  Within the limits of this study, BL was found to have an antimicrobial/growth-inhibiting effect on P. gingivalis, and a-PDT using a combination of BL and RB shows promise as a new technical modality for bacterial elimination in periodontal therapy.
authors: Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, Tokyo, Japan.
authors: C
authors: C
authors: Chui
authors: A
authors: A
authors: Aoki
authors: Y
authors: Y
authors: Takeuchi
authors: Y
authors: Y
authors: Sasaki
authors: K
authors: K
authors: Hiratsuka
authors: Y
authors: Y
authors: Abiko
authors: Y
authors: Y
authors: Izumi
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques; D004396:Coloring Agents / Q000494:pharmacology; D004923:Erythrosine / Q000494:pharmacology; D005452:Fluoresceins / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology*; D006801:Humans; D010778:Photochemotherapy / Q000295:instrumentation* / Q000379:methods; D017319:Photosensitizing Agents / Q000494:pharmacology*; D016966:Porphyromonas gingivalis / Q000187:drug effects*; D012395:Rose Bengal / Q000494:pharmacology; D013696:Temperature; D014048:Tolonium Chloride / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D004396:Coloring Agents; D005452:Fluoresceins; D005456:Fluorescent Dyes; D017319:Photosensitizing Agents; D014048:Tolonium Chloride; D012395:Rose Bengal; D004923:Erythrosine; C085059:phloxine
keywords: Porphyromonas gingivalis; antimicrobial photodynamic therapy; blue light-emitting diode; rose bengal