Crevicular fluid is a serum ultrafiltrate that accumulates in gingival connective tissue resulting from increased vascular permeability. When its production increases, it passes to the gingival crevice.
Gingival crevicular fluid contains products derived from microbial plaque, tissue breakdown, host cells, and host immunity that, in some instances, have been demonstrated to be related to the active phases of periodontal destruction.
Aspartate aminotransferase (AST) is an enzyme normally confined to cell cytoplasm, but is released to the extracellular environment upon damage. AST levels in serum and other body fluids ( cerebrospinal fluid, arthritic joint fluids) have been used for several decades as a laboratory diagnostic
aid for assessing tissue destruction (i.e.MI, hepatitis). Furthermore, the amount of AST activity observed generally reflects the
extent of cell death and, consequently, the magnitude of tissue destruction. AST activity greatly depends on cellular damage in periodontal tissues. Levels of various inflammatory cytokines can also be determined in GCF.
The periimplant gingival sulci has been shown to be similar to the periodontal crevice with respect to gingival fluid flow. In spite of this observation, to date relatively few studies have focused their attention on the investigation of the periimplant crevicular fluid (PCF) components and
their relationship with the peri-implant condition.
Functions of GCF:
• Promotes adhesion of the gingival crevice epithelium to the enamel through the presence of salivary and plasma proteins.
• Defense through the presence of inflammatory cells and molecules.
• Elimination of micro-organisms and food debris through the washout effect of fluid formation.
Composition of GCF:
• electrolytes: sodium, potassium, calcium.
• amino acids and bioamines: alanine, lysine, histamine, cadaverin, and putrescin
• plasma proteins: albumin, fibrinogen, transferrin, plasminogen,macroglobulin
• salivary proteins: mucins, lysozyme
• imunoglobulins: IgG, IgA, and IgM
• prostaglandins, leucotrienes.
Dr Iswarya V
Reference : Carranza Periodontology