Changes in saliva protein composition in patients with periodontal disease

Periodontitis is a chronic inflammatory disease characterized by tissue destruction which is usually diagnosed through clinical and radiographic signs. The detection of changes in the chemical composition of saliva could be used to reflect gingivo-periodontal alterations. The aim of this study was to identify salivary parameters that could identify different stages of the periodontal disease. The study group included 118 adults, 89 of them with mild, moderate or severe chronic periodontitis. The remaining participants comprised the control group. Total saliva was analyzed for physical and chemical properties. Dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used for protein detection and zymography for type IV collagenase identification. Salivary flow rate, pH and buffer capacity showed similar values in all groups. Proteins were augmented in severe periodontitis, as also shown by SDS-PAGE. Hydroxyproline rose significantly in all periodontal groups as secretory Immunoglobulin A significantly diminished compared with the control group. An increase in peroxidase was detected in moderate and severe periodontitis. All salivary samples contained 200-116-92 kDa gelatinases; minor bands at 66-31 kDa were also present in all periodontitis groups. Calcium levels showed significant differences between all periodontitis groups compared with the control group. Quantitative changes in the chemical composition of the saliva of patients with periodontal disease could be of significance in the diagnosis and progression of periodontal disease.