Bone resorbing activity and cytokine levels in gingival crevicular fluid before and after treatment of periodontal disease

Background: The aim of the present study was to investigate bone resorption activity (BRA), interleukin-1alpha (IL-1alpha), IL-1beta and interleukin-1 receptor antagonist (IL-1ra) in gingival crevicular fluid (GCF) in sites with no signs of periodontol disease and in sites with horizontal or angular loss of periodontal bone. These assessments were performed before and after periodontal treatment. Methods: GCFs were collected from 10 individuals with filter strips from two healthy sites and four sites with deep pathological periodontal pockets, two of which showed horizontal bone loss and two with angular bone loss. All diseased pockets were treated with flap surgery and systemic Doxyferm(R). Twelve months later GCF was collected again and treatment outcome evaluated. BRA in GCFs was assessed in a bone organ culture system by following the release of Ca-45 from neonatal mouse calvariae. The amounts of IL-1alpha, IL-1beta and IL-1ra in GCFs were quantified by enzyme-linked immunosorbent assay (ELISA). Results: Treatment resulted in reduction of pocket depths with 3.5+/-0.5 mm in sites with angular bone loss and 2.8+/-0.3 mm in sites with horizontal bone loss. Initially, BRA, IL-1alpha, IL-1beta and IL-1ra were significantly higher in GCFs from diseased sites compared with healthy sites. No differences in BRA and cytokine levels were seen between GCFs from pockets with horizontal and angular bone losses. The levels of IL-1alpha, IL-1beta and IL-1ra were significantly reduced after treatment of diseased pockets. Pocket depths were significantly correlated to BRA only in pre-treatment sites with angular bone loss. BRA was correlated to Il-1alpha, IL-1beta, but not to IL-1ra, in diseased sites with angular bone loss, before and after treatment. The reductions of BRA in the individual sites, seen after treatment, were not correlated to the reductions of Il-1alpha, IL-1beta or IL-1ra. Conclusions: These data show that BRA and cytokine levels are increased in GCFs from sites with periodontal disease and that periodontal treatment results in reduction of the cytokines. Our findings further indicate that IL-1alpha and IL-1beta play important roles for the BRA present in GCFs, but that other factors also contribute to this activity.