Tenascin‐C and Matrix Metalloproteinase‐9 Levels in Crevicular Fluid of Teeth and Implants

ABSTRACT Background: The role of and interaction between bacterial infection and biomechanical impact in the development of peri‐implant inflammatory processes is not clear. Objective: To determine the amount and concentration of tenascin‐C (TNC) in gingival crevicular fluid (GCF) around teeth and in peri‐implant sulcus fluid from healthy implants and implants with peri‐implantitis, and to correlate it with matrix metalloproteinase‐9 (MMP‐9) levels. Materials and Methods: Seven control individuals and 18 patients with 41 implants with/without peri‐implantitis were included. GCF was collected with filter strips and volumes were measured with a Periotron device. The amount of serum albumin per sample was quantified by densitometric analysis of Coomassie‐stained sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Relative activity of MMP‐9 was determined from the densitometry of zymograms. Amounts and concentrations of TNC were evaluated by ELISA. Results: Relative MMP‐9 activity was increased in peri‐implantitis. A tendency was observed to measure higher TNC concentrations at teeth than at implants. The amount of TNC in GCF collected from healthy implant sites and the peri‐implantitis sites was significantly different. Based on immunoblotting, TNC in GCF seemed degraded. In contrast to TNC, MMP‐9 was significantly related to the PD and the volume of GCF. Conclusion: TNC is known to be induced in inflammation. The increase found in peri‐implantitis was less than expected. In the context of peri‐implantitis, TNC might be a marker of bone remodelling rather than inflammation and infection. A possible proteolytic degradation of TNC during peri‐implantitis needs to be studied.