[Bacteriological examination of subgingival flora in patients with marginal periodontitis].

Before and 4 weeks after a single course of local treatment, the composition of subgingival microflora of 15 patients with marginal periodontitis was determined by cultural and microscopical examination. A significant reduction in the number of gram-negative microorganisms could be achieved by this treatment. Anaerobic sporeless rods like Bacteroides and Fusobacteria but also Spirochetes, Eikenella and Capnocytophaga were involved in the inflammation. The number of Actinomyces in the subgingival flora was also significantly reduced by therapy. After treatment the number of gram-positive bacteria like Streptococci and Corynebacteria was significantly increased. The reduction in the number of these gram-negative bacteria in line with the reduction of periodontal inflammation is a criterion of their significance in the etiology of marginal periodontitis.