title: Irradiation by light-emitting diode light as an adjunct to facilitate healing of experimental periodontitis in vivo.
abstract: OBJECTIVE
  This study evaluated the biostimulatory effect of 660 nm light-emitting diode (LED) as an adjunct in the treatment of experimental periodontitis.
  
  
  METHODS
  Ninety-six Sprague-Dawley rats underwent experimental periodontitis by placement of a silk ligature followed with or without additive Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) injection. Irradiation with LED light was performed at varying energy densities of 5, 10 and 15 J/cm2, 1 d after debridement and detoxification. Rats were killed at 3, 7 and 14 d after irradiation with LED light, and the effect of irradiation was evaluated by descriptive histology and quantitative measurements of periodontal bone loss, inflammatory infiltration and cellular proliferation.
  
  
  RESULTS
  Reduction of inflammation, accelerated collagen deposition and realignment was noted following irradiation with LED light at densities of 10 and 15 J/cm2, and temporary reduction of periodontal bone loss, as well as bundle bone apposition, was noted at day 3 in rats treated with 10 J/cm2 light. The biomodulatory effect was stronger in sites treated with Pg-LPS injection. In sites without Pg-LPS injection, temporary reduction of inflammation was noted in all LED light-irradiated specimens at day 3. No significant change in cellular proliferation was noted in any LED light-treated group.
  
  
  CONCLUSIONS
  LED light (660 nm) with an energy density of 10 J/cm2 appeared suitable as an adjunct modality for periodontitis by temporarily reducing inflammation, facilitating collagen realignment and bundle bone deposition. Future studies will aim to amplify the biostimulatory effect of LED light by adding a supplementary medium or repeated irradiation.
authors: Faculty of Dentistry, National University of Singapore, Singapore, Singapore. dencpc@nus.edu.sg
authors: P-C
authors: PC
authors: Chang
authors: L-Y
authors: LY
authors: Chien
authors: Y
authors: Y
authors: Ye
authors: M-J
authors: MJ
authors: Kao
mesh_terms: D016301:Alveolar Bone Loss / Q000473:pathology / Q000532:radiotherapy; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D049109:Cell Proliferation / Q000528:radiation effects; D002710:Chlorhexidine / Q000627:therapeutic use; D003094:Collagen / Q000528:radiation effects; D003238:Connective Tissue / Q000473:pathology / Q000528:radiation effects; D005881:Gingiva / Q000473:pathology / Q000528:radiation effects; D005884:Gingival Hemorrhage / Q000473:pathology / Q000532:radiotherapy; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D008026:Ligation / Q000295:instrumentation; D008070:Lipopolysaccharides / Q000009:adverse effects; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D010012:Osteogenesis / Q000528:radiation effects; D057747:Periodontal Debridement / Q000379:methods; D010513:Periodontal Ligament / Q000473:pathology / Q000528:radiation effects; D010518:Periodontitis / Q000473:pathology / Q000532:radiotherapy*; D016966:Porphyromonas gingivalis; D011879:Radiotherapy Dosage; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000891:Anti-Infective Agents, Local; D008070:Lipopolysaccharides; D003094:Collagen; D002710:Chlorhexidine