Relationship between periodontal disease status and combination of biochemical assays of gingival crevicular fluid

Background: Currently, no biochemical assay involving gingival crevicular fluid is utilized routinely as a screening test for periodontal disease. Objective: The objective of the present study was to evaluate the potential of gingival crevicular fluid assay as a screening methodology. Methods: The subject population was comprised of 27 volunteers. Nine participants were classified as ‘subject with periodontal destruction’ (SPD) exhibiting at least one site with pocket depth and attachment loss > 3.5 mm, whereas the remaining individuals were categorized as ‘subject with minimal periodontal destruction’ (SMD). Gingival crevicular fluid was collected from fixed sites via a standardized method. Biochemical assays of 12 substances (hemoglobin, albumin, transferrin, α1‐antitrypsin, fibronectin, IgA, IgG, IgM, lactoferrin, myeloperoxidase and neutrophil elastase) were conducted at a commercial laboratory. Power transformation of total quantities in gingival crevicular fluid was performed for statistical analysis. Results: Relationships between total quantity of each substance and periodontal disease status were unclear. Logistic regression analysis yielded six predictive models, which consisted of substance pairs: neutrophil elastase/IgA, neutrophil elastase/hemoglobin, neutrophil elastase/α1‐antitrypsin and neutrophil elastase/IgG, and IgA/albumin and IgA/transferrin (p