Type I collagen carboxyterminal telopeptide in human gingival crevicular fluid in different clinical conditions and after periodontal treatment.

A total of 126 gingival crevicular fluid (GCF) samples were collected from 20 adults using paper strips. Patients were divided into a periodontitis-affected group (13 subjects) and a periodontitis-free group (7 subjects) by pocket depth and radiological bone loss. 4 subjects from the periodontitis-affected group received a single episode of periodontal treatment (scaling, root planing and curettage) and GCF samples were collected 2, 5, 10, 20 and 40 days after treatment. Type I collagen carboxyterminal telopeptide (ICTP) in GCF was extracted into saline solution and determined by a radioimmunological method. Mean GCF ICTP concentration was 425 micrograms/l (SEM 45) in periodontitis patients and 148 micrograms/l (SEM 25) in periodontitis-free subjects, i.e., GCF ICTP concentrations were about 100 x higher than serum reference values. Significant positive correlations were found between GCF ICTP total amount per site and plaque index (R = 0.362), papilla bleeding index (R = 0.259), pocket depth (R = 0.464) and radiological bone loss (R = 0.418). Periodontal treatment decreased GCF ICTP concentration to the level seen in healthy subjects. However, large variations were seen between subjects and sites. ICTP levels below the detection limit were often found in deep pockets, as well as high values in periodontitis-free subjects. It was concluded that GCF ICTP reflects the local type I collagen degradation in periodontal tissues, and probably gives information about the tissue destruction process beyond the reach of the clinical parameters.