An immunological principle, reactive to carious antigen in precipitin tests, occurs in greater amounts in blood of caries-free than in blood of caries- susceptible patients, measured by amounts of precipitate obtained with the same carious antigen. Complement-fixation tests gave positive results— greater with antigen from carious than with antigen from normal dentin. These results were definitely related to precipitin reactions with serum from the same patients, and therefore to the existing state of caries-susceptibility or caries-immunity. The results bore no relation to those of the Wassermann test with the same sera.
References: J. Den. Res., 1933; Brit. Den. J., 1934; Studies in the aetiology of dental caries, 1938 (John Bale, Sons and Danielsson,London).