[Bacterial invasion in periodontitis, is it important in periodontal treatment?]

During the progression of periodontal disease bacteria invade the epithelial lining of the gingival pocket and the underlying connective tissue. This invasion was demonstrated in acute necrotizing ulcerative gingivitis (ANUG), localized juvenile periodontitis (LJP), rapidly progressive periodontitis in adults (RPP) and in children with Papillon-Lefèvre syndrome associated periodontitis. Using morphologic criteria or fluorescent antibody staining techniques spirochetes, Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, B. intermedius, Actinomyces species, Fusobacterium nucleatum and Mycoplasma have been identified in these tissue compartments. Recent light microscopic, electron microscopic and bacteriological studies demonstrated the presence of invading bacteria in the cementum and in the radicular dentin of teeth with periodontal disease. In 83% of 69 carries free periodontally diseased teeth bacteria were present in one of the dentin layer from the root. In 59% of these teeth the dental pulps contained bacteria. The composition of the flora resembled that of the subgingival flora. The use of chlorhexidine, fluoride, tetracyclines or metronidazole in the elimination of invading bacteria following mechanical periodontal therapy is discussed.