[Periodontal diseases].

Research into pathogenesis and therapy of periodontal diseases have advanced considerably over the last 15 years. Basic research has disclosed anatomic and morphologic "weak spots" in the periodontium at the marginal gingiva and the interdental space. Approximately 70 microorganisms were isolated, among them many gram negative anaerobic bacteria. Products of these bacteria comprise of enzymes which destroy the periodontal connective tissue and interfere with immunologic mechanisms. Based on this knowledge several diseases are differentiated. A correct diagnosis contributes to a favorable therapy, such that the common periodontitis of adults (PA) responds well to treatment and the other periodontitis-forms are amenable to stabilisation if the patient cooperates. For the general practitioner the particular risks are elucidated. Already an examination for periodontitis and more so local treatment induces a bacteremia in every patient. Dentists and referring physicians should envisage preventive measures in patients at risk.