Peculiarities of oral microbiota in patients with small and medium-sized dental defects and chronic periodontitis of moderate severity

BACKGROUND: Сhronic generalised periodontitis is one of the most widespread pathologies of the dento-mandibular system. To date, even if there is evidence of bacterial etiology, no biological markers have been developed to qualitatively assess the possibility of inflammation of periodontal tissues or its pathomorphosis to a more severe stage. AIMS: Study of peculiarities of oral microbiota in patients with acquired defects of dental rows in chronic generalised periodontitis of medium severity. MATERIALS AND METHODS: The study participants were 88 people with small/medium dental defects with no clinical signs of periodontal tissue inflammation (the first group) and chronic generalised periodontitis of medium severity (the second group). In order to assess the dental status, an index assessment of periodontal tissues and the intensity of tooth decay was carried out, and the degree of tooth mobility was determined. Using microbiological methods, biomaterial from the mucous membrane of the denture bed tissues was studied with determination of microorganisms composition. DNA of periodontal pathogens was detected and quantified by polymerase-chain reaction. Statistical analysis was performed using the Shapiro-Wilk criterion, t-criterion and χ2 criterion. RESULTS: The mean values of CFE and PMA indices in group 2 patients were 1.5 and 5.7 times higher, respectively, than in group 1. When analysing the composition of microorganisms in biological material from patients with chronic generalised periodontitis of moderate severity, Neisseria spp. were statistically significantly more common (p=0.002), Candida spp. (p=0.035), Enterobacterales (p=0.001), Enterococcus spp. (p=0.03) and statistically significantly lower Corynebacterium spp. (p=0.001) and S. salivarius (p=0.001). In the presence of partial defects of tooth rows in patients, the stated microorganisms formed persistent communities, the nature of symbiotic relations in which determined the clinical manifestations of inflammatory changes in the soft tissues of the periodontium. CONCLUSIONS: The increased incidence of Candida spp. and Enterobacterales in patients with acquired dental defects and periodontal soft tissue inflammation, as well as the formation of persistent relationships between them and antagonistic effects on oral autochthonous bacteria, is of interest for the development of targeted antimicrobial therapy in preparation for dental prosthetic treatment.