Immunochemical studies on dental calculus--immunological studies of periodontal disease. 3

Abstract

It has already been pointed out that dental calculus is one of major factors in periodontal disease. Recent finding by fluorescent antibody technique is suggesting the immunologic response in the inflamed gingiva.It leads to the hypothesis that calculus may play an important role in periodontal tissues as antigen.Rabbits were immunized with calculus, heat-immobilized calculus or lyophilized organic substance of calculus as antigens. Using immune sera of treated rabbits, antigen-antibody reactions were performed by PCA-method (Passive Cutaneous Anaphylaxis) and Agar Gel Double Diffusion (Immuno-diffusion) for the analysis of the antigenicity of calculus, calculus extract, dental plaque, saliva, serum protein and experimental calculus in vitro.The results were as follows:1. PCA-reaction in guinea pigs with calculus extract antigen was evidently positive, : suggesting the existence of some allergens provoking cutaneous anaphylaxis.In Agar Gel Double Diffusion experiments, 2. Natural calculus formed four precipitin bands against immune serum of rabbit immunized with human calculus. It indicated that calculus contained at least four saline soluble antigens.3. Calculus extract semi-purified by physical and chemical procedures composed of two groups, of which the saline soluble fraction produced two precipitin bands. The other salineinsoluble fraction gave only one band.4. When the rabbits antisera reacted with the filtrates of EDTA-demineralized calculus obtained through Membrane filter or Ultra-fine filter, the appearance of precipitin bands changed according to the pore size of filters. This suggested the possible separation of several antigenic substances by the choice of filters.5. Dental plaque yielded two bands against antiserum.6. The concentrated whole saliva gave three bands, while concentrated parotid saliva gave only one detectable band.7. Gamma globulin and albumin in human serum formed respectively one clear-cut band.8. Several bands were observed between antisera and experimental calculus in vitro which was formed from incubated saliva and mineral salts.9. The findings mentioned above indicate the close serological relationship between calculus antigens and oral proteins such as dental plaque, saliva, serum protein and oral microbes.