Immunochemical study of host proteins in human supragingival compared with denture plaque.

The contribution of proteins from saliva and gingival crevicular fluid (GCF) to plaque was determined by comparing extracts of supragingival plaque of unknown age formed on normal teeth with plaque formed on artificial teeth in complete or partial dentures where crevicular fluid is absent. There was a total absence of albumin and a virtual absence of IgG from denture plaque samples, confirming their crevicular origin. The concentration of lactoferrin was much higher than that of lysozyme in all supragingival but not in the denture plaque samples, suggesting that GCF provided more lactoferrin than lysozyme to plaque. Amylase was a component in both denture and supragingival plaque, present in similar amounts in both deposits. Cysteine-containing phosphoproteins from saliva were in low concentration but present in all plaque samples; proline-rich proteins were virtually absent, reflecting the high vulnerability to proteolysis of these proteins. Salivary proteins in plaque extracts do not correspond with their relative concentrations in saliva.