Mycotic flora characteristics of the endontic flora in patients affected by COVID-19

BACKGROUND: Owing to the fact that, presently, at a dental appointment, it is possible to observe a wide range of consequences arising after COVID-19, among which are observed lesions of the pulp and periodontium of the tooth, additional diagnostic methods should be introduced before choosing treatment tactics. In our previous study, we analyzed the contents of root canals of teeth in patients who had COVID-19 using bacterioscopy. Coccus flora was detected in all cases and elements of Candida yeast-like fungi were recorded in 89 cases (76.1%). Based on the obtained data, it was advantageous to perform microbiological examination of the endodontium in this group of patients to further study their physical and chemical properties and correct the treatment regimen in gangrenous form of chronic pulpitis and aggravated forms of periodontitis, which determined the relevance of the present study.

AIM: To reveal the characteristics of the mycotic flora of the endodontium in patients who previously had COVID-19.

MATERIALS AND METHODS: A bacteriologic study of root canal contents in patients who had previously undergone a new coronavirus infection at different times, diagnosed as “exacerbation of chronic periodontitis”, “chronic gangrenous pulpitis”, and “acute suppurative periodontitis”, was conducted to detect fungi of the genus Candida in the tooth root canal system, which was obtained during mechanical treatment with a sterile endodontic instrument. The patients (n=49) were divided into groups according to their final diagnosis: group 1, chronic gangrenous pulpitis (27 patients); group 2, acute purulent periodontitis (9 patients); and group 3, exacerbation of chronic periodontitis (13 patients). Then, the collected material was placed in a tube with Amies transport medium and sent to the laboratory. Seeding of the material was performed in sterile Petri dishes on Sabouraud agar by rubbing with a plastic spatula. Further, Petri dishes were placed in the thermostat for 24–48 hours of incubation at 37±10 °C. Then, the study was carried out according to the generally accepted scheme: the obtained cultures were identified to species by the character of growth on dense medium.

RESULTS: The given bacteriological study of the patients’ endontic contents confirmed the data of bacterioscopy and concretized the previously obtained results. On final examination, black colonies of Candida albicans were observed in 95.92% of cases. No growth of Candida albicans colonies was observed in two cases (4.08%).

CONCLUSION: The bacteriologic study performed after bacterioscopy of diagnosis confirmed the presence of fungi of the genus Candida in the root canals of teeth in patients who previously had COVID-19. The study showed that when treating similar patients, the high risk of infection of periodontal complex tissues by Candida fungi should be considered. It is advisable to supplement the standard protocols of endodontic treatment with physical exposure, for example, laser radiation, or additional medication with antifungal drugs, such as fluconazole.