A Sequential Bacteriological and Serological Investigation of Rhesus Monkeys Immunised Against Dental Caries with Streptococcus Mutans

Abstract

In a serial investigation of the effects of immunization with S. mutans in rhesus monkeys maintained on a human type cariogenic diet, the numbers of S. mutans in cervical plaque, crevicular-fluid washings, fissures of teeth and in saliva were lower in immunized animals than in sham-immunized controls. Immunization caused a delay in initial colonization and a slowing of the rate of colonization with S. mutans. These bacteriological changes were associated with a reduction in the smooth-surface-caries score. No relationship was found between the presence of S. sanguis and caries, but there was an inverse relationship between the proportions of S. mutans and S. sanguis isolated. Increased titers of complement-fixing, hemagglutinating and precipitating antibodies to S. mutans were found in the sera of immunized but not of control monkeys. A significant increase in salivary hemagglutinating antibodies was not detected. Immunization with S. mutans causes an increase in serum antibodies and a reduction in the number of S. mutans in the oral flora, and these are associated with a reduction in dental caries.