The modern level of knowledge on the etiology and pathogenesis of periodontal disease identifies microbial factor as the dominant cause of the development of aggressive and typical forms of periodontitis. The study involved 125 patients with chronic generalized periodontitis and aggressive forms of periodontitis divided in 2 groups. The treatment tactics was chosen selectively depending on the amount of periodontopathogenic microorganisms revealed by real-time PCR. In patients treated with antibiotics this amount decreased significantly resulting in clinical improvement and rapid remission.