The article describes a joule metric information-measuring system developed by the authors for non-invasive express diagnostics of periodontal tissue states. The information-measuring system is based on the joule metric method for rapid assessment of electrochemical parameters changing in biological objects under inflammatory processes, tissue destruction, or tissue remodeling after treatment. The dependence of tissue resistance to the electrical impulse transmitted via it is determined by the physiological state and morphological features, which allows the use of their electrical conductivity measurement in biological and medical studies. The use of joule metric methods makes it possible to obtain information on the biological object status at the time of examination to plan further treatment of the patient. An examination of 40 patients with periodontal diseases, and 20 healthy subjects with intact periodontium was conducted. The correlation between joule metric parameters and changes in periodontal tissues depending on the phase and course of inflammatory process, and the amount of tissue damage was revealed. Thus, joule metric information-measuring systems can be used in clinical practice for non-invasive rapid diagnosis of periodontal diseases, as well as for dynamic assessment of ongoing therapy.