DETERMINATION OF ROOT CANAL MICROBIOTA IN CHRONIC APICAL PERIODONTITIS AND EVALUATION OF THE MICROBIOLOGICAL ACTIVITY SPECTRUM OF POLYHEXANIDE AGAINST THE IDENTIFIED MICROBIAL FLORA

Introduction: Chronic apical periodontitis is characterized by the formation of a stable mixed microbial flora within the root canal system. To improve the effectiveness of endodontic treatment, it is necessary not only to identify the microbiological composition of infected canals but also to select an irrigant with proven activity against key pathogens. Materials and Methods: Microbiological samples were obtained from 35 patients with chronic apical periodontitis. The identification of microbiota was performed using cultural methods, MALDI-TOF MS, and 16S rRNA sequencing. The antibacterial activity of various irrigants, including Lavasept solution at concentrations of 0.1% and 0.2% (polyhexanide-based) sodium hypochlorite 3% and 2% chlorhexidine bigluconate, was evaluated against the most frequently isolated strains of primary microflora. Results: The most frequently detected microorganisms in the samples were Streptococcus mutans (42.86%), Streptococcus sanguinis (28.57%), Actinomyces israelii (34.29%), and Porphyromonas gingivalis (31.43%). Upon one-hour exposure, Lavasept solutions at concentrations of 0.1% and 0.2% completely inhibited the growth of these microorganisms, demonstrating equivalent effectiveness to 2% chlorhexidine bigluconate and 3% sodium hypochlorite. Conclusions: Polyhexanide-based solutions exhibit pronounced bactericidal activity against the main pathogens of chronic apical periodontitis. The obtained data support the feasibility of using polyhexanide-based solutions as an antiseptic irrigant in endodontic practice. © 2025 Elsevier B.V., All rights reserved.