Cathepsin K levels in the crevicular fluid of dental implants: a pilot study

Objective: To determine the concentration of cathepsin K secreted into the crevicular fluid around dental implants and its correlation with clinical parameters of healthy implants and implants showing clinical signs of peri‐implantitis. Material and Methods: Nineteen patients with 40 implants with and without peri‐implantitis were enrolled in the study. Peri‐implantitis was diagnosed by the pocket probing depth (PD), the modified bleeding index (MBI), the modified plaque index (MPI) and by radiographic signs of bone loss. Gingival crevicular fluid collected from the buccal and lingual sites was adsorbed to filter strips. Cathepsin K levels and total protein within the crevicular fluid were determined by immunoassay and the bicinchoninic method, respectively. Results: Cathepsin K per filter strip normalized to the time of collection was 10.1 (0–33.5) pmol/sample around control implants and 22.4 (3.7–56.3) pmol/sample in the peri‐implantitis group. The difference between the medians was significant (p