title: Influence of titanium on in vitro fibroblast-Porphyromonas gingivalis interaction in peri-implantitis.
abstract: OBJECTIVE
  Titanium wear particles have been found in peri-implant tissues, but their role in the pathogenesis of peri-implantitis remains unclear. We aimed to determine the in vitro inflammatory responses of peri-implant granulation tissue fibroblasts (PIGFs) to titanium particles alone and in the presence of viable Porphyromonas gingivalis.
  
  
  METHODS
  Peri-implant granulation tissue fibroblasts were challenged either with TiO2 particles, P. gingivalis or a combination of TiO2 particles and P. gingivalis. Gene expression and protein production of pro-inflammatory mediators by PIGFs were measured with PCR and ELISA, respectively.
  
  
  RESULTS
  Higher doses of TiO2 were toxic to PIGFs and in sub-toxic doses, TiO2 caused an increase in gene expression of tumour necrosis factor (TNF)-A and increased protein production of TNF-α, interleukin (IL)-6 and IL-8. A challenge with P. gingivalis alone induced gene expression of TNF-A, IL-1β, IL-6 and IL-8. A combined challenge with TiO2 and P. gingivalis caused a stronger increase in gene expression of TNF-A and protein production of TNF-α and MCP-1 than P. gingivalis alone.
  
  
  CONCLUSIONS
  TiO2 particles and P. gingivalis, individually, can induce pro-inflammatory responses in PIGFs. Furthermore, TiO2 particles and viable P. gingivalis further enhance gene expression and production of TNF-α by PIGFs. Therefore, Ti wear particles in the peri-implant tissues in combination with P. gingivalis infection may contribute to the pathogenesis of peri-implantitis by enhancing the inflammation in peri-implant tissues.
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam ACTA, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Irshad
authors.forename: Nina
authors.initials: N
authors.lastname: Scheres
authors.forename: Wim
authors.initials: W
authors.lastname: Crielaard
authors.forename: Bruno G
authors.initials: BG
authors.lastname: Loos
authors.forename: Daniel
authors.initials: D
authors.lastname: Wismeijer
authors.forename: Marja L
authors.initials: ML
authors.lastname: Laine
mesh_terms: D001431:Bacteriological Techniques; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000032:analysis; D003764:Dental Materials / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D005786:Gene Expression Regulation; D015964:Gene Expression Regulation, Bacterial; D006097:Granulation Tissue / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D008297:Male; D008875:Middle Aged; D057873:Peri-Implantitis / Q000209:etiology* / Q000276:immunology / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000276:immunology*; D014025:Titanium / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: C111835:CCL2 protein, human; C508606:CXCL8 protein, human; D018932:Chemokine CCL2; D003764:Dental Materials; C508600:IL6 protein, human; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; C009495:titanium dioxide; D014025:Titanium
keywords: Porphyromonas gingivalis; biomaterial; cytokines; fibroblast; inflammation