O microbioma associado à lesão de cárie radicular difere do microbioma oral recolhido no esmalte saudável do mesmo indivíduo?

Abstract

Introduction: Root caries is an increasingly prevalent condition in older adults, associated with age-related factors such as oral hygiene, medication use, and changes in the oral microbiome. Understanding bacterial dynamics in these lesions may support more effective preventive strategies. Goal: To compare the microbial profile of root caries lesions with the healthy oral biofilm from the same individual, focusing on Streptococcus mutans, Actinomyces naeslundii, and Streptococcus mitis. Materials and methods: Samples of saliva, healthy oral biofilm, and root caries lesion biofilm were collected from individuals aged 65 years or older. Bacterial quantification was performed using qRT-PCR to assess the relative load of each species in the different ecological niches. Results: Substantial interindividual variability was observed. In some cases, lower bacterial loads were found in the lesions, while in others, higher concentrations of cariogenic species were detected. S. mitis showed a more consistent presence across both environments, suggesting greater ecological resilience. Conclusion: The microbiome associated with root caries may differ considerably from the healthy oral microbiome, reflecting potential local or systemic imbalances. This study highlights the importance of microbial dynamics in assessing caries risk, particularly in elderly populations.

Date of Award	28 Jul 2025
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Maria José Correia (Supervisor) & Pedro Lopes (Co-Supervisor)