title: Innate immune receptor expression in peri-implant tissues of patients with different susceptibility to periodontal diseases.
abstract: BACKGROUND
  Although inflammation mediates the pathogenesis of periodontal diseases, the effects of innate immune responses on implant therapies have not been evaluated. Innate immune receptors, including toll-like-receptors (TLRs) and the receptor for advanced glycated end-products (RAGE), are upregulated within inflamed gingiva and are responsible for initiation of detrimental host responses. The aim of this study is to compare the expression of TLR2, TLR4, and RAGE in gingival tissues from participants susceptible to periodontitis and participants not susceptible to periodontitis before and after implant therapy.
  
  
  METHODS
  Periodontally healthy participants received implant therapy for non-periodontal edentulism. Participants susceptible to periodontitis were diagnosed with chronic periodontitis prior to implant therapy. Gingival biopsies were collected from edentulous ridges before implant installation and from peri-implant mucosa 2 months after treatment. Histology, real-time PCR, and Western blot were used to evaluate levels of inflammatory infiltrate, TLR2, TLR4, and RAGE expression.
  
  
  RESULTS
  Before implant therapy, elevated levels of RAGE were detected in gingival tissues from participants susceptible to periodontitis when compared to those from participants with healthy periodontiums, whereas no differences in the expression of TLR2 or TLR4 were detected. After implant therapy, there was an upregulation of RAGE and TLR4 levels that coincided with a downregulation of TLR2 levels in biopsies from participants susceptible to periodontitis. Levels of RAGE and TLR4 remained unchanged in biopsies from participants with healthy periodontiums, whereas TLR2 levels were significantly upregulated. Histologically, post-implant biopsies from participants susceptible to periodontitis displayed higher levels of inflammatory infiltrate.
  
  
  CONCLUSIONS
  Elevated levels of inflammatory potential were found after implant therapy in participants susceptible to periodontitis.
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL 32608, USA. tkoutouzis@dental.ufl.edu
authors.forename: Theofilos
authors.initials: T
authors.lastname: Koutouzis
authors.forename: Dominick
authors.initials: D
authors.lastname: Catania
authors.forename: Kathleen
authors.initials: K
authors.lastname: Neiva
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Wallet
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D015153:Blotting, Western; D055113:Chronic Periodontitis / Q000276:immunology*; D015331:Cohort Studies; D015921:Dental Implants; D004198:Disease Susceptibility / Q000276:immunology; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D005881:Gingiva / Q000276:immunology; D005884:Gingival Hemorrhage / Q000276:immunology; D005889:Gingival Recession / Q000276:immunology; D017127:Glycation End Products, Advanced / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000276:immunology; D010514:Periodontal Pocket / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000032:analysis*; D051195:Toll-Like Receptor 2 / Q000032:analysis; D051197:Toll-Like Receptor 4 / Q000032:analysis; D015854:Up-Regulation / Q000276:immunology; D055815:Young Adult
chemical_list: D015921:Dental Implants; D017127:Glycation End Products, Advanced; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4