HOST PROTEINS IN DENTAL PLAQUES OF CARIES-RESISTANT VERSUS CARIES-SUSCEPTIBLE HUMAN GROUPS

The level of host proteins in 3 day supragingival plaque extracts was compared in caries-resistant (CR) and caries-susceptible (CS) adults with little or no gingival inflammation to minimize the contribution of gingival crevicular fluid (GCF). Except for IgA, all the host proteins examined were present at similar levels in both groups of subjects. Although the IgA exhibited fragmentation on sodium dodecylsulfate gradient-polyacrylamide gel electrophoresis (SDS-PAGE) and transfer electrophoresis in both groups, the amount of binding to a standard antisecretory IgA antiserum was higher in CR than in CS subjects. This could be a reflection of the trend towards a higher concentration of IgA in saliva of CR subjects or the result of less proteolytic activity in CR plaque. Even in 3 day plaque in the absence of gingival inflammation, GCF contributes a significant share of the host proteins to plaque extracts. Salivary proteins in plaque do not parallel their relative concentration in saliva.