This invention relates to the prevention of dental caries, and more particularly to a method for immunization against caries employing either of two polysaccharides which are involved, together with the microorganisms by which they are elaborated, in caries formation; or utilizing the corresponding enzymes responsible for the biosynthesis of such polysaccharides.
Recent studies have indicated that the formation of carious lesions on teeth is related to the interaction between carbohydrates (notably sucrose) in the diet and specific bacteria on tooth surfaces. The cariogenic bacteria, predominantly streptococci, adhere to the surfaces of teeth by synthesizing extracellular polysaccharides from the sucrose. These polymers, which are generally either polyglucans or polyfructans (levan), "glue" the bacterial cells together and help them adhere to the teeth. The polysaccharides thus promote action between the bacteria and further sucrose ingested by the host animal and thereby facilitate the formation of further polysaccharides. Moreover, the extracellular polysaccharides thus produced are believed to play significant roles in plaque formation and in the consequent development of caries.
A number of vaccines have been proposed for immunization against dental caries in animals. Various of these proposals are summarized in the copending application of Gaffar and Kestenbaum for "Vaccines for the Prevention of Dental Caries", Ser. No. 360,964 filed May 16, 1973 allowed as U.S. Pat. No. 3,879,545, as a continuation-in-part of their prior application Ser. No. 126,933 filed Mar. 22, 1971 and now abandoned. This copending application, the disclosure of which is incorporated by reference herein, relates to caries-preventive vaccines incorporating as the active ingredient thereof a polyfructan (or levan) polysaccharide produced by elaboration of certain strains of streptococcus, particularly Streptococcus Strain SS2. This immunization technique has been found to result in the formation of antibodies against the heterogeneous microorganisms in the recticuloendothelial system and in the blood, and to result in significant decreases in the formation of carious lesions in host animals subjected to inoculation with such organisms.
It is a principal object of the present invention to provide an improved method for immunization against dental caries, utilizing vaccines incorporating the polysaccharide of the aforesaid copending application, another polysaccharide believed to be involved in the formation of dental plaque, or enzymes involved in the synthesis of both such polysaccharides, which method results in markedly decreased caries formation. Other objects and advantages of this invention will be apparent from the following detailed description of preferred embodiments thereof.