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

Objectives: 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.

Material and 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.

Keywords: biomaterial(s); cytokine(s); dental abutments; oral implants/implantology; titanium; zirconium oxide.

Conflict of interest statement

The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article.

© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Figures

Figure 1

Figure 1A: Clinical example of a paper strip sampling technique at an implant-supported restoration to quantify PICF pro-inflammatory cytokine and bone-mediator protein expression adjacent to an abutment of either titanium or zirconia. Paper strips were positioned at four line angles of the implant restoration sampled for all subjects. Figure 1B: Classification of pro-inflammatory cytokines/chemokines assessed by PICF sampling and quantified using a multiplexed fluorescent bead-based immunoassay instrument. Figure 1C: Bone metabolism mediators assessed by PICF sampling and quantified using a multiplexed fluorescent bead-based immunoassay instrument.

Figure 2

Figure 2A: Box plot depiction of leptin distribution between zirconia and titanium abutment groups sampled in picograms/30 seconds. Figure 2B: Scatter plot of osteopontin (OPN) as a function of age. OPN was significantly correlated with age after adjustment for multiple comparisons.