title: Peri-Implant Sulcus Fluid (PISF) Matrix Metalloproteinase (MMP) -8 Levels in Peri-Implantitis.
abstract: BACKGROUND
  Matrix Metalloproteinase (MMP) -8 plays crucial role in pathogenesis of periodontitis and is also a possible biomarker candidate in peri-implantitis.
  
  
  OBJECTIVE
  The aim of the study was to analyse MMP-8 levels in peri-Implant Sulcus Fluid (PISF) from peri-implantitis affected implants in smoking and non-smoking patients with different periodontal health status of natural teeth before and after peri-implantitis treatment.
  
  
  METHODS
  Altogether 29 patients with peri-implantitis were recruited and divided into two study groups (11 with healthy periodontium or gingivitis, i.e. no marginal bone loss, and 18 with chronic periodontitis).
  
  
  METHODS
  PISF sample from one implant with peri-implantitis from each patient was collected at the baseline and six months after conservative and surgical peri-implantitis treatment, and clinical parameters were registered. Samples were analysed for MMP-8 with dento ELISA method applying a monoclonal antibody. Mucosal cell samples were also analysed for IL-1 gene polymorphism. PISF MMP-8 levels' differences between periodontal diagnosis groups and between smokers' and non-smokers' were analysed. Also, IL-1 polymorphism profiles were compared between study groups.
  
  
  RESULTS
  PISF MMP-8 levels were higher at the baseline compared to and after the treatment when all sampled implant sites were analysed together (p = 0.001). MMP-8 levels' distribution was broader in periodontitis patients' PISF samples, and only in periodontitis patients' group levels decreased statistically significantly after the treatment (p = 0.005). Smokers'and non-smokers' PISF MMP-8 was at similar level both at the baseline and after the treatment. No difference between distributions of IL-1 genotypes was found between study groups.
  
  
  CONCLUSIONS
  MMP-8 levels increase in peri-implantitis affected implants both in non-periodontitis and periodontitis patients, but levels still after treatment of the condition reflect intensified host response around implants and indicate challenges of controlling peri-Implantitis with any treatment modality.
authors.affiliation: Department of Dental Medicine - periodontology, German Armed Forces Hospital , Berlin, Germany .
authors.forename: René
authors.initials: R
authors.lastname: Thierbach
authors.affiliation: Department of Oral and Maxillofacial Diseases, University of Helsinki , Helsinki, Finland; 2) Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland; 3) Division of Periodontology, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden.
authors.forename: Kurt
authors.initials: K
authors.lastname: Maier
authors.affiliation: Dentognostics GmBH , Jena, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Sorsa
authors.affiliation: Department of Oral and Maxillofacial Diseases, University of Helsinki , Helsinki, Finland .
authors.forename: Päivi
authors.initials: P
authors.lastname: Mäntylä
keywords: Host response; Oral implants; Periodontitis; Point-of-care diagnostics