Method for preventing alveolar pyorrhea

A method for preventing, alveolar pyorrhea which comprises the steps of applying to gingival placque and periodontal disease causing Actinomyces viscosus inherently present in and insoluble from the interdental spaces and oral cavity of a host infected with said Actinomyces viscosus, a fructan-degrading enzyme-containing composition originated from a material selected from the group consisting of moulds belonging to the genuses Aspergillus, Fusarium, Humicola, Penicillium, Talaromyces, Eupenicillium, Sporotorichum, Chaetomium, Gelasinospora and Stachybotrys, bacteria belonging to the genuses Arthrobacter, Streptococcus, Streptomyces and Actinomyces, at a ratio ranging from 1 to 300 activity units per g. or ml. of the composition, said enzyme being in the free state, and thereafter washing out from said interdental spaces and oral cavity Actinomyces viscosus fungus set free therein by enzyme action.