Dental plaque microbiota in preschool children receiving palliative care and the effects of herbal infusions, furacilin, and chlorhexidine on strain biofilms

Relevance. The duration of palliative care in children is determined by the underlying medical condition and often extends over many years. Therefore, timely diagnosis, prevention, and treatment of dental diseases are of critical importance, as the severity of the primary condition can significantly complicate dental interventions. Despite notable advances in this field, investigation of the oral microbiota composition in children with disabilities as an additional noninvasive approach for the early identification of caries risk factors still requires a unified understanding of the mechanisms underlying dental plaque formation and the pathogenesis of dental hard tissue diseases in this patient population. The rationale for using dental plaque as the study material is based on its complex physiological role in the development of dental hard tissue diseases, as well as the accessibility of diagnostic sample collection.

Materials and methods. To analyze the dental plaque microbiota, a comprehensive clinical oral examination was performed in 15 children aged 6 years. Microbiological assessment included determination of the total microbial count and identification of bacterial and fungal strains, along with evaluation of their basic microbiological characteristics. Biofilms of the isolated strains were formed in flat-bottom microtiter plates and subsequently treated with herbal infusions, furacilin solution, and chlorhexidine. Biofilm thickness was assessed using crystal violet staining followed by ethanol extraction.

Results. Bacteriological examination of 15 dental plaque samples enabled the isolation and identification of 45 bacterial and fungal strains. The microbial community was dominated by representatives of the genus Staphylococcus — 16 strains (35.6%) isolated from 13 samples (86.7%). The majority of the isolated strains demonstrated a high capacity for biofilm formation. Conventional antiseptic agents (chlorhexidine and furacilin) showed little or no effect on mature biofilms. Infusions of all tested medicinal herbs effectively reduced the biofilm thickness of coagulase-positive staphylococci but had no significant effect on coagulase-negative species. Chamomile and nettle infusions demonstrated antibiofilm activity against Neisseria spp.; calendula and nettle infusions were effective against enterobacteria; and calendula and chamomile infusions reduced Candida biofilms.

Conclusion. Bacteriological analysis of dental plaque in children receiving palliative care revealed a diverse microbial composition, with predominance of enterobacteria and staphylococci. Conventional antiseptic agents (chlorhexidine and furacilin) showed minimal effects on the biofilm thickness of clinical strains. In contrast, the herbal infusions evaluated in this study exhibited pronounced antibiofilm activity.

1. Danilova M.A., Machulina N.A., Zalazaeva E.A. Experience of joint work of the Department of Pediatric Dentistry and Orthodontics of the Perm SMA and the Centre of Complex Rehabilitation of Disabled People. Pediatric dentistry and dental prophylaxis. 2013;44(1):70- 72 (In Russ.). Available from: https://elibrary.ru/item.asp?id=19034146

2. Ponomareva A.G., Krivoshchapov M.V., Vorobyova N.A., Lakshin A.M. Modern aspects of rehabilitation of patients with infantile cerebral paralysis (literature review). Cathedra. Dental education. 2019;(70):48-51 (In Russ.). Available from: https://elibrary.ru/item.asp?id=42938088

3. Oliveira AC, Paiva SM, Martins MT, Torres CS, Pordeus IA. Prevalence and determination factors of malocclusion in children with special needs. European journal of orthodontics. 2011;33(4):413-418. https://doi.org/10.1093/ejo/cjq094

4. Schultz ST, Shenkin JD, Horowitz AM. Parental perceptions of unmet dental need and cost barriers to care for develop mentally disabled children. Pediatr Dent. 2001;(4):321-325. Available from: https://pubmed.ncbi.nlm.nih.gov/11572490/

5. Gromova S.N., Kolevatykh E.P., Koledaeva A.K., Krivokorytov K.A., Maltseva O.A., Medvedeva M.S., et al. Relationship between the changes in plaque microbiota and the oral hygiene status during the period of supervised toothbrushing in 6-year-old children. Pediatric dentistry and dental prophylaxis. 2023;23(2):133-142 (In Russ.). https://doi.org/10.33925/1683-3031-2023-609

6. Antonova A.A. Local prevention of caries in children and correction of nutrition. Dal'nevostočnyj medicinskij zhurnal. 2006;(4):117-120 (In Russ.). Available from: https://elibrary.ru/item.asp?id=21152190

7. Leontiev V.K. Mineralizing function of saliva and its features. The Dental Institute. 2022; (2):82-83. (In Russ.). Available from: https://www.elibrary.ru/item.asp?id=49265016

8. Distel V.A., Skripkina G.I., Romanova Y.G. The masticatory apparatus reduction and dental caries. The Dental Institute. 2017;(2):40-41 (In Russ.). Available from: https://instom.spb.ru/catalog/article/10645/

9. O’Toole G.A. Microtiter dish biofilm formation assay. J. Vis. Exp. 2011;47:2437. https://doi.org/10.3791/2437

10. Stepanović S, Vuković D, Hola V, Di Bonaventura G, Djukić S, Cirković I, et al. Quantification of biofilm in microtiter plates: overview of testing conditions and practical recommendations for assessment of biofilm production by staphylococci. APMIS. 2007;115(8):891-899. https://doi.org/10.1111/j.1600-0463.2007.apm_630.x