Concentrations of fibronectin in the sera and crevicular fluid in various stages of periodontal disease.

While fibronectin (FN) has previously been demonstrated to be present in gingival crevicular fluid (GCF), its quality and quantity has not been reported. Since this information is relevant for ongoing studies on the use of FN for gingival reattachment, we performed these measurements and compared plasma levels in healthy subjects, patients with gingivitis and periodontitis, and in patients undergoing maintenance therapy. Plasma and GCF samples were obtained from 4 sites in each subject using a Periotron to permit quantification of samples. FN concentrations were determined in a microELISA using hyperimmune anti-FN antibody. Purified FN served as a reference for quantification. The functional activity of each sample was assessed by examining the natural affinity of FN for gelatin. Subjects with gingivitis and those in maintenance had significantly depressed levels of plasma fibronectin. While little fibronectin could be detected in the GCF of healthy sites regardless of patient category, examination of the most diseased sites in each group revealed that the concentration of FN in the GCF was highest in health and reduced when there was gingival inflammation. In no case was GCF FN found to be biologically active.