title: Comparison of pro-inflammatory cytokines and bone metabolism mediators around titanium and zirconia dental implant abutments following a minimum of 6 months of clinical function.
abstract: OBJECTIVE
  Dental implant abutments are fundamental prosthetic components within dentistry that require optimal biocompatibility. The primary aim of this cross-sectional study was to preliminarily assess differences in the pro-inflammatory cytokine and bone metabolism mediator protein expression in the peri-implant crevicular fluid (PICF) adjacent to transmucosal abutments.
  
  
  METHODS
  Abutments were fabricated from either titanium or zirconia in patients previously receiving single-tooth implant therapy. All subjects sampled in this study had an identical implant system and implant-abutment connection. Participants (n = 46) had an average time of clinical function for 22 months (6.2-72.8 months, ±SD 17 months) and received a clinical and radiographic examination of the implant site at the time of PICF sampling using a paper strip-based sampling technique. Cytokine, chemokine, and bone metabolism mediator quantities (picograms/30 s) were determined using a commercial 22-multiplexed fluorescent bead-based immunoassay instrument. A total of 19 pro-inflammatory cytokines and seven bone metabolism mediators were evaluated.
  
  
  RESULTS
  Multivariable analyses provided no evidence of a group (titanium or zirconia), gender, or age effect with regard to the expression of pro-inflammatory mediators evaluated. Significant (P = 0.022) differences were observed for the bone mediator leptin, with titanium abutments demonstrating significantly elevated levels in comparison with zirconia. Osteopontin demonstrated a significant (P = 0.0044) correlation with age of the subjects.
  
  
  CONCLUSIONS
  No significant differences in pro-inflammatory cytokine or bone metabolism mediator profiles were observed biochemically, with the exception of leptin, for the abutment biomaterials of titanium or zirconia The molecular PICF findings support the observed clinical biocompatibility of both titanium and zirconia abutments.
authors.affiliation: Craniofacial Clinical Research Center, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Barwacz
authors.affiliation: Dows Institute for Dental Research, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Brogden
authors.affiliation: Dows Institute for Dental Research, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Clark M
authors.initials: CM
authors.lastname: Stanford
authors.affiliation: Dows Institute for Dental Research, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Deborah V
authors.initials: DV
authors.lastname: Dawson
authors.affiliation: Dows Institute for Dental Research, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Erica N
authors.initials: EN
authors.lastname: Recker
authors.affiliation: Dows Institute for Dental Research, The University of Iowa College of Dentistry, Iowa City, IA, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Blanchette
mesh_terms: D000328:Adult; D000368:Aged; D017076:Computer-Aided Design; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000378:metabolism*; D000044:Dental Abutments; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D005260:Female; D005883:Gingival Crevicular Fluid / Q000737:chemistry*; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014025:Titanium; D015040:Zirconium
chemical_list: D016207:Cytokines; D006728:Hormones; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: biomaterial(s); cytokine(s); dental abutments; oral implants/implantology; titanium; zirconium oxide