Collagen I carboxyterminal propeptide in human gingival crevicular fluid before and after periodontal treatment.

The amount of procollagen I carboxyterminal propeptide (PICP) in crevicular fluid (CF) was measured in three periodontitis patients. Samples were collected from 29 sites before treatment (scaling, root planing, and curettage) and 2, 5, 10, 20, and 40 days after treatment, by placing two paper strips in periodontal pockets for 5 s. The amount of fluid in strips was measured by the Periotron device. Control samples were collected from subjects with minimal gingival inflammation. PICP was extracted into saline solution and determined by a radioimmunologic method. Plaque index, papilla bleeding index, and pocket depth were recorded before and 40 days after treatment. The CF PICP mean concentration was 4.2 mg/l in the pretreatment samples. Five days after treatment a statistically significant increase in PICP concentration was seen in all subjects. The peak appeared on days 5 or 10 in 27 sites. The mean peak PICP concentrations of the subjects were 5-10 times higher than the pretreatment values. Twenty days after treatment, mean PICP concentration decreased to pretreatment level. PICP concentrations did not correlate with the clinical parameters. In control samples PICP amounts were below the detection limit. CF PICP is a new marker of type I collagen metabolism in periodontal tissues. It was concluded that elevated PICP concentrations in CF after periodontal treatment reflected increased type I collagen synthesis in periodontal tissues and that the peak in type I collagen synthesis takes place 5-10 days after treatment.