DIAGNOSTIC SIGNIFICANCE OF MICROBIOLOGICAL SCREENING IN PERI-IMPLANTITIS

Abstract

INTRODUCTION. Peri-implantitis is one of the most common complications of dental implantation, characterized by inflammatory and destructive changes in the tissues surrounding the implant. Microbial factors play a leading role in its pathogenesis, particularly the formation of dysbiotic biofilm communities that differ from the microbiota of healthy peri-implant tissues and periodontal lesions. Studying the spectrum of microorganisms and their associations is essential for improving diagnostic and therapeutic approaches. The aim of the study to investigate the microbial profiles of the peri-implant microbiota in peri-implantitis and to identify the dominant microbial complexes associated with the inflammatory process. Materials and Methods. The study was conducted on the basis of clinical databases of the departments of the Faculty of Dentistry of the State Higher Educational Institution “Uzhhorod National University”. In 2024–2025, 252 patients with stage II–III periodontitis were examined. A total of 491 bacterial isolates were obtained from the peri-implant zone. The samples were cultured on nutrient media using the sectoral inoculation method according to Gold on differential diagnostic media (Himedia, India). Anaerobic representatives of the microbiota were cultivated on Schaedler agar supplemented with 5% sheep blood (Himedia, India). Anaerobic conditions were provided using the AnaeroGen System (Oxoid, UK). Results. In 39 patients, one dominant bacterial species was isolated; in 148 patients – two species; and in 52 patients – three predominant pathogens. The most frequently isolated bacteria were Streptococcus spp. (41.1%), Peptostreptococcus spp. (17.1%), Porphyromonas spp. (10.6%), Prevotella spp. (7.9%), and Staphylococcus spp. (6.1%). Less frequently, Actinomyces spp., Enterococcus spp., Enterobacterales spp., Fusobacterium spp., and Rothia spp. were detected. Characteristic pathogen associations included Streptococcus spp. + Porphyromonas spp., Streptococcus spp. + Prevotella spp., Peptostreptococcus spp. + Porphyromonas spp., among others. Conclusions. Peri-implantitis is a complex polymicrobial infection that develops as a result of successional changes in the microbiota and the formation of dysbiosis. The dominance of opportunistic and anaerobic periodontopathogenic microorganisms in clinically significant titers confirms their leading role in the development of the inflammatory process. The results highlight the importance of microbial screening for optimizing antimicrobial therapy and developing preventive strategies in the management of patients with peri-implantitis.