Evaluation of receptor activator of nuclear factor-κB ligand and osteoprotegerin levels in saliva and gingival crevicular fluid in patients with chronic periodontitis

Background and objective: Recent findings have suggested that osteoclastogenesis is directly regulated by receptor activator of nuclear factor-κB ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG).Aim: Evaluate and compare the level of RANKL and OPG and its ratio (RANKL/OPG ratio) in saliva and gingival crevicular fluid (GCF) of patients with chronic periodontitis and clinically healthy individuals.Patients and methods: Ninety patients were selected and divided into group 1: 45 patients with clinically healthy gingiva as a control group. Group 2: 45 patients with moderate to severe chronic periodontitis probing pocket depth, bleeding on probing, plaque index and attachment level were measured, unstimulated whole saliva and GCF samples were collected from four deepest sites in different quadrants, both analyzed by enzyme-linked immunosorbent assays.Results: All periodontal indices (pocket depth, bleeding on probing, plaque index and attachment level) were significantly higher in the test groups than in the control group, it was found that RANKL and RANKL/OPG ratio significantly increased while OPG level significantly decreased in GCF and saliva in the chronic periodontitis group compared with the controlled group.Conclusion: Both GCF and saliva collection are a noninvasive approaches as a diagnostic markers for RANKL, OPG and RANKL/OPG ratio.