title: Platform switching and matrix metalloproteinase-8 levels in peri-implant sulcular fluid.
abstract: OBJECTIVE
  The concept of platform switching has been introduced to implant therapy, however long-term data are sparse. The aim of this study was to biochemically investigate the inflammatory response mediated by MMP-8 to platform switching after 3 years of loading, in order to understand the long-term effect of implant/abutment mismatching on peri-implant health.
  
  
  METHODS
  A total of 70 implants had been inserted in the posterior maxilla in 26 patients and were randomly assigned to one of the four treatment regimens (implant diameter 3.8 [control group], 4.3 [Test group 1, T(1)], 4.8 [Test group 2, T(2)] and 5.5 mm [Test group 3, T(3)]). All implants were restored using a 3.8 mm abutment. In the test groups, this restoration resulted in a mismatching of 0.25-0.85 mm of implant-abutment diameters.
  
  
  RESULTS
  Thirty-six months after prosthetic rehabilitation, peri-implant sulcular fluid samples were taken from two aspects of all implants and from periodontally healthy adjacent teeth. Samples were processed in a conventional ELISA using monoclonal antibodies recognizing the active entity of MMP-8. In the test groups, MMP-8 mean values were 2.76 ng for T(1) (SD: 2.91), 3.30 ng for T(2) (SD: 1.94) and 3.18 ng for T(3) (SD: 2.46). For the control group, MMP-8 mean value was 3.6 ng (SD: 2.23), whereas 3.38 ng (SD: 2.2) was recorded at the adjacent teeth. There were no statistically significant differences in MMP-8 values between the groups (P=0.113, Kruskal-Wallis).
  
  
  CONCLUSIONS
  The presence of an implant/abutment mismatching specific for this prosthetic concept is compatible with long-term peri-implant health as demonstrated by analysis of a sensitive biomarker of the peri-implant inflammatory response.
authors: luigicanullo@yahoo.com
authors: Luigi
authors: L
authors: Canullo
authors: Giuliano
authors: G
authors: Iannello
authors: Lutz
authors: L
authors: Netuschil
authors: Søren
authors: S
authors: Jepsen
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology / Q000517:prevention & control; D016723:Bone Remodeling; D001862:Bone Resorption; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005883:Gingival Crevicular Fluid / Q000201:enzymology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000032:analysis*; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D018709:Statistics, Nonparametric
chemical_list: D015921:Dental Implants; D020784:Matrix Metalloproteinase 8