Mapping the Evidence on Oral Health Interventions and Cognitive Status in Alzheimer's Disease: A Scoping Review.

BACKGROUND

Oral health is increasingly recognized as a potentially modifiable factor in Alzheimer's disease (AD), although its influence on cognitive outcomes remains uncertain.

METHODS

This scoping review followed the Arksey and O'Malley framework and was reported in accordance with PRISMA-ScR guidelines. Searches were conducted in PubMed, Scopus, and Web of Science through August 2025. Eleven studies met the inclusion criteria: one randomized controlled trial, one nonrandomized trial, and nine observational studies.

RESULTS

Poor oral health, including tooth loss, periodontal disease, and impaired mastication, was consistently associated with worse cognitive and dementia-related outcomes. Interventions improved oral and functional measures but yielded limited and inconsistent evidence of cognitive benefit. Proposed mechanisms, including systemic inflammation and microbiome alterations, were infrequently evaluated directly.

CONCLUSIONS

Overall, oral health correlates with cognitive status in AD, but the causal impact of interventions remains uncertain, highlighting the need for rigorous trials with standardized cognitive and mechanistic outcomes.