Gingival crevicular fluid from patients with periodontitis contains bone resorbing activity

Inflammatory processes occurring in the vicinity of bone tissue often result in stimulation of osteoclast activity and loss of skeletal mass. The aim of the current study was to determine if inflammatory exudates collected from gingival pockets in patients with periodontitis contain factors capable of stimulating resorptive activity. The degree of bane mineral mobilization and bone matrix degradation was assessed by analysis of the release of Ca-45 and H-3 from bones prelabelled with (CaCl2)-Ca-45 and [H-3]proline, respectively, Gingival crevicular washings from six patients with signs of periodontitis stimulated Ca-45 or H-3 release from the calvarial bones. The stimulatory effect of the gingival crevicular washings on Ca-45 release was concentration- and time-dependent, and reduced by calcitonin, a specific osteoclast inhibitor. These data demonstrate that crevicular fluid contains factor(s) which can stimulate osteoclastic degradation of bone in vitro. The bone resorbing activity was partially retained after extensive dialysis. Analysis of the concentrations of prostaglandin E-2, interleukin-1 alpha and interleukin-1 beta in the crevicular fluids, and comparisons of these agents as stimulators of Ca-45 release in the mouse calvarial assay, suggest that prostaglandin E-2 is not the sale factor responsible for the bone resorbing activity of the exudates. The data indicate that other factors, such as IL-1, may play key roles in the stimulation of osteoclastic activity by gingival crevicular washings.