Periodontal lesions in hamsters and gnotobiotic rats infected with actinomyces of human origin

Abstract

Albino hamsters infected with a catalase negative strain of Actinomyces of human origin developed a root surface and periodontal syndrome similar to that previously described in hamsters. Deposits of radicular plaque developed, and areas of alveolar bone resorption were noted adjacent to tooth surfaces that had been coated with copious amounts of plaque. Gingival plaque contained large numbers of microorganisms with identical characteristics to those of the infecting strain. Groups of gnotobiotic rats were separately infected with two human strains of Actinomyees , one of which was representative of A. viscosus . Gingival distortion, pocketing, alveoloclasia, and root caries were associated with the impaction of hair fibers and the formation of bacterial mats on root surfaces. In many areas bacterial coats had spread over more than half of the exposed root surfaces of maxillary first and second molars. Primary and secondary dentin was often destroyed by an invasion of these microorganisms that in some cases penetrated to the pulp chamber.