title: Effect of laser phototherapy on the release of TNF-alpha and MMP-1 by endodontic sealer-stimulated macrophages.
abstract: OBJECTIVE
  Our aim was to analyze the effect of laser phototherapy on the secretory activity of macrophages activated by interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS), and stimulated by substances leached from an epoxy resin-based sealer (AH-Plus) and a calcium hydroxide-based sealer (Sealapex).
  
  
  BACKGROUND
  Laser phototherapy can modulate the inflammatory process, improving wound healing. This type of therapy could be useful for modulating postoperative symptoms seen after endodontic treatment.
  
  
  METHODS
  Cytotoxicity was indirectly assessed by measuring mitochondrial activity. Macrophages were stimulated by the leached substances or not (controls), and the groups were then irradiated or not. The secretion of pro-inflammatory cytokines (TNF-alpha and MMP-1) was analyzed using ELISA. Two irradiations at 6-h intervals were done with an As-Ga-Al diode laser (780 nm, 70 mW, spot size 4.0 mm(2), 3 J/cm(2), for 1.5 sec) in contact mode.
  
  
  RESULTS
  The sealers were non-cytotoxic to macrophages. The production of TNF-alpha was significantly decreased by laser phototherapy, regardless of experimental group. The level of secretion of MMP-1 was similar in all groups.
  
  
  CONCLUSIONS
  Based on the conditions of this study we concluded that in activated macrophages, laser phototherapy impairs the secretion of the pro-inflammatory cytokine TNF-alpha, but has no influence on MMP-1 secretion.
authors.affiliation: Departamento de Dentística, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Lorena R
authors.initials: LR
authors.lastname: Sousa
authors.forename: Bruno N
authors.initials: BN
authors.lastname: Cavalcanti
authors.forename: Márcia M
authors.initials: MM
authors.lastname: Marques
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000633:toxicity; D002470:Cell Survival; D002478:Cells, Cultured; D007371:Interferon-gamma / Q000494:pharmacology; D054023:Lasers, Semiconductor; D008070:Lipopolysaccharides / Q000494:pharmacology; D028022:Low-Level Light Therapy; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins; D012387:Root Canal Filling Materials / Q000633:toxicity*; D012459:Salicylates / Q000633:toxicity; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D012387:Root Canal Filling Materials; D012459:Salicylates; D014409:Tumor Necrosis Factor-alpha; C055601:Sealapex; D007371:Interferon-gamma; D020781:Matrix Metalloproteinase 1; D002126:Calcium Hydroxide