Cytokine expression in peri-implant crevicular fluid in relation to bacterial presence

Aim:The aim was to assess clinical inflammatory parameters, cytokine levels and bacterial counts in samples from implant crevicular fluid in cases with untreated peri-implantitis. Material and Methods: Several bacterial species known to up-regulate pro-inflammatory cytokines have been associated with peri-implantitis. The Luminex magnet bead technology was used to study cytokines in crevicular fluid. The checkerboard DNA-DNA hybridization method was used to study bacterial counts in samples from 41 implants (41 individuals). Results: Profuse bleeding and suppuration was found in 25/41 (61.0%) of the implants. The reliability of duplicate cytokine processing was high. In the presence of profuse bleeding, higher pg/ml levels of IL-1 (p=0.02), IL-8 (p=0.04), TNF- (p=0.03) and VEGF (p=0.004) were found. Higher concentrations of IL-1 were found in the presence of suppuration, and if Escherichia coli (p=0.001) or Staphylococcus epidermidis (p=0.05) could be detected. Conclusion: Profuse bleeding and/or suppuration in untreated peri-implantitis can be associated with higher concentrations of IL-1, IL-8, TNF- and VEGF in peri-implant crevicular fluid. A higher concentration of IL-1 in peri-implant crevicular fluid was found in samples that were positive for E.coli or S.epidermidis.