Immunoglobulins in human dental plaque

Immunoglobulins have been found previously in human gingiva, gingival fluid, serum and smeas of dental plaque. In the present study their presence and distribution in situ have been studied by immunofluorescence on the approximal surfaces of childen's teeth extracted due to caries or for orthodontic reasons. There wee also preliminary investigations of S. mutans distribution and of plaque immunoglobulins in grossly carious adult teeth. Positive fluorescence was in the order total Ig > IgG > IgA > IgM. S mutans (serotype c) was found in two of seven samples. Fluorescence was most marked at the apical plaque border, especially in relation to the contact area. This may relate to the prevalence of lysed organisms in this region. The topography and distribution of the different immunoglobulins correlate with previous studies suggesting gingival fluid (via plasma and gingival plasma cells) as the main source of the plaque immunoglobulin at the site of onset of approximal caries and chronic inflammatory periodontal disease.