The textbook presents the part of therapeutic stomatology which deals with problems of etiology, pathogenesis, clinical course, diagnosis, treatment, prevention and general questions of periodontal and oral mucosa diseases. The textbook deals with issues of anatomy and physiology of the periodontium and oral mucosa, clinical features, diagnosis, treatment and prevention of periodontal and oral mucosa diseases. Special attention is given to medicamental, surgical treatment (curettage, gingivectomy, flap operations etc.), physiotherapy (electrotherapy, ultrasound therapy, vacuum therapy, massage and so on). A separate chapter describes methods of examination of the patient. Self-control tests with answer keys are given for knowledge assessment. Textbook is established in accordance with the approved educational program and curriculum in therapeutic dentistry for students of higher education establishments. The textbook is intended for students of dental faculty of higher medical education establishments, interns, dentists.