Investigation of microcirculation in the periodontium can be beneficially conducted with certain devices like a multifunctional laser diagnostic complex "LAKK-M" and simultaneously using a number of non-invasive diagnostic methods. The study evaluates the following characteristics:
1) Microhemodynamics (laser Doppler fluometry – LDF method)
The essence of this method is that a low-intensity monochromatic light beam emitted by a laser diode embedded in a Doppler laser flowmeter passes through a flexible light guide and through the tip of the sensor illuminates the tissue under study. In the fabric, the light is scattered by reflecting particles. Part of the light is reflected back and passes through the receiving light guide to the internal photodetector of the device. In accordance with the Doppler effect, only moving particles (mainly red blood cells) lead to a frequency shift. The spectrum of the received signal is processed in the device in accordance with the algorithm obtained by Bonner for this type of reflection, and the flow volume (ml/min/100 g of tissue) is calculated. Thus, the LDF method is based on the measurement of the Doppler component in the spectrum of the reflected laser signal scattered on the shaped blood elements moving in the microvessels.
2) Delivery and consumption of oxygen in the microcirculatory bed (optical tissue oximetry – GRT method)
The method of optical tissue oximetry (GR) estimated delivery and consumption of oxygen in the microvasculature; and the relative volume fraction of erythrocytes (Vr) in the study of $\approx$ 4-5 mm3 and saturation mixed-blood (that is, arteriole and venules)
3) Saturation of arterial blood with oxygen (pulse oximetry method)
4) Content of oxidative metabolism enzymes (laser fluorescent diagnostics (LPD) method))
The spectrum of reflected radiation of the tissue is recorded when a laser beam probes it with a wavelength corresponding to the wavelength of the maximum absorption of the beam by a certain enzyme, sources with three wavelengths are used to excite the fluorescence of enzymes (nicotinamides, flavins, lipofuscin, porphyrin, etc.): 365 nm, 532 nm and 630 nm. Diagnosis of the main functions of the microcirculatory bed in the form of their comprehensive assessment (LDF + OTO + LPD) is more informative compared to the individual methods mentioned above, since microcirculation is variable and adapts to the specific physiological needs of the tissue. An integrated approach to the study of tissue in vivo allows obtaining complementary data on microdynamics, oxygen consumption and the state of metabolic processes for their analysis and decision-making in dental diagnostics.