Presents a modern understanding of the role of periodontophatogenic bacteria types: Aggregatibacter actinomycetemcomitans (Actinobacillus actinomycetemcomitans), Tannerella forsythia (Bacteroides forsythus) and Porphyromonas gingivalis as indicators of periodontitis emergence and development risk. Therminological definitions are given of factors, indicators and markers of risk of periodontium inflammatory diseases development that show the level of importance of their association with the disease as well as the quantitative evaluation of these associations.

Dentists prefer macrolide antibiotics, protected penicillins, and fluoroquinolone combined with 5-nitroimidazole. All patients have taken antibiotics themselves at least once a year. Microbial complexes in patients with acute and exacerbated apical periodontitis in 79% of cases are susceptible to amoxicillin/clavulanic acid, to azithromycin - 52%, lincomycin - 36%, 5-nitroimidazole - 68%, ciprofloxacin - 73.7%. In patients with apical abscess high rates of resistance of microbial complexes to all types of antibiotics was revealed (33% for lincomycin 76,1% for ciprofloxacin, 28,6% for 5-nitroimidazole). Patients with moderate to severe periodontitis in 90.5% are sensitive to amoxicillin/clavulanic acid and azithromycin, in 62.4% to lincomycin. Sensitivity to ciprofloxacin was detected in 85.7% of patients, in 14.3% - moderate resistance.

Aim. Comparative study of frequency of detection of genetic markers of resistance to antibiotics forming in anaerobic bacteria under the conditions of mixed biofilms in a clinical setting and comparison of data of phenotypic and genotypic methods of study. Materials and methods. 66 strains of bacteria forming biofilm with PCR detection of antibiotics were studied: Streptococcus sanguinis, Streptococcus salivarius, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and anaerobic pathogens - Porphyromonas gingivalis, Tannerella forsythia, Parvinonas micra, Prevotella intermedia. Modelling of microbial biofilms in vitro and scanning electron microscopy were carried out. Results. The studied strains of resident and pathogenic microbiota were established to have genes that code resistance to P-lactam antibiotics, carbapenems, macrolides, tetracyclines. Genetic markers of resistance to p-lactam antibiotics (STX-M и МЕСА - cepha-losporines), including carbapenems (VIM and NDM, but not Oxa-48), glycopeptides (VanA and VanB), macrolides (ERM), tetracycline (Tet) and QNRB plasmids (fluoroquinolones) were detected in strains by PCR. Conclusion. The most frequently used preparations in dental practice - metronidazole and lincomycin (for the last 20 - 30 years) have shown the highest number of resistant strains - 52.3 and 22.7%, respectively. The frequency of detection of genetic markers of resistance to other studied preparations did not exceed 2.5 - 11.4%. Minimal quantity of resistant strains of anaerobic bacteria was detected for carbapenems and fluoroquinolones.

The place of high-tech methods of molecular biology in clinical laboratory diagnostics of various diseases and the development of a system of biomarkers as an important component of diagnostic research is currently attracting the closest attention of the scientific community. In this paper, an attempt is made to use high-tech metagenomic analysis to solve problems that arise due to the high frequency of association of periodontal diseases with systemic pathology, in particular, with type 2 diabetes mellitus. The aim of the study was to determine the taxonomic and metabolic features of the microbiome of periodontal tissues in periodontal diseases associated with type 2 diabetes mellitus, as a model of the ratio of local and systemic effects of periodontal pathogenic bacteria. The study included 16S shotgun sequencing of bacterial DNA as part of biological material from periodontal pockets/dentoalveolar furrows of 46 people - 15 patients with chronic periodontitis associated with type 2 diabetes mellitus, 15 patients with chronic periodontitis unrelated to systemic pathology, as well as 16 healthy people in the control group, followed by bioinformatic processing of the data obtained. The obtained data allowed us to establish the taxonomic features of the periodontal microbiome in the association of chronic periodontitis with type 2 diabetes mellitus, which included the predominance of representatives of the families Prevotellaceae and Spirochaetaceae in its composition. The features of metabolic processes in periodontal tissues with the participation of the microbiome were also revealed, which consisted in an increase in the exchange of cysteine and methionine against the background of a decrease in the metabolism of pyrimidine, methane, sphingolipids, and the synthesis of fatty acids, which are of diagnostic value in assessing the condition of patients with type 2 diabetes mellitus.

Aim. To determine the relationship between surface roughness and surface topography of the basic dental polymethyl methacrylate polymer polished by different methods and microbial adhesion of microorganisms (Porphyromonas gingivalis, Fusobacterium nucleatum and Streptococcus sanguis) and fungi (Candida albicans) causing periodontal diseases. Methods. Surface topography of the basic dental polymethyl methacrylate polymer was studied by atomic force microscopy; microbiological methods were used to study the adhesion of bacteria and Candida fungi causing periodontal diseases to the surfaces of the samples polished by different methods. Results. It was shown that Streptococcus sanguis had the highest adhesion degree to the polymer surface after milling, Porphyromonas gingivalis and Candida albicans had moderate, and Fusobacterium nucleatum - low adhesion degree. The adhesion dropped significantly after the sample had been polished in dental laboratory or using the «Ergo Boxing» compared to dental unit polishing, where the decrease was less significant. The article contains 2D- and 3D-atomic force microscopy pictures of polymer surface after different polishing methods use. Images obtained by atomic force microscopy clearly display the surface of the basic dental polymethyl methacrylate polymer polished by different methods. Conclusion. Polymer samples processed by «Ergo Boxing» and dental laboratories are characterized by minimal microbial adhesion when compared with other methods.