Cbp+ Streptococcus mutans and Candida albicans are associated with Root Caries in older adults

Gingival recession becomes more prevalent with age, exposing root surfaces and increasing susceptibility to root caries, particularly among older adults. With the global population aging and root caries cases expected to rise, it is essential to better understand the risk factors contributing to this condition. This cross-sectional study enrolled 117 adults aged 65 years or older, including 56 with root caries and 61 without. Saliva and site-specific plaque samples were collected to assess levels of Mutans streptococci and Candida spp., alongside microbiome composition. Demographic, behavioral, biological, dental, and medical factors were also examined. Participants with root caries demonstrated significantly higher salivary counts of Mutans streptococci and Candida spp. compared to healthy individuals. Co-infection with C. albicans and S. mutans, particularly Cbp+ S. mutans, markedly increased the risk of root caries. Plaque microbiome analysis revealed an overrepresentation of Capnocytophaga leadbetteri in root caries lesions. Additionally, individuals with root caries were more likely to report xerostomia, less likely to use an electric toothbrush, and less likely to floss daily. Collectively, this study provides a comprehensive evaluation of microbial, biological, medical, and behavioral factors associated with root caries in older adults, highlighting critical targets for prevention and management strategies.