Regular dental scaling and dementia risk: a nationwide nested case-control study.

BACKGROUND: Dementia is a major public health issue. Emerging evidence suggests that periodontal disease and dental calculus are associated with increased risk of dementia or may serve as potential risk indicators. The role of dental scaling in prevention remains unclear. This study aimed to investigate whether regular dental scaling is associated with dementia risk across age groups. METHODS: We conducted a nested case-control study using data from the Taiwan National Health Insurance Research Database between 2000 and 2019. Cases were individuals with a first-time diagnosis of dementia during the study period, and controls were age-, sex-, and residence-matched individuals without dementia. Conditional logistic regression models were used to evaluate the association between dental scaling and the risk of dementia. A two-sided p-value < 0.05 was considered statistically significant. RESULTS: The study included 162,038 participants. After adjusting for potential confounders, dental scaling was associated with modestly lower odds of dementia (OR 0.95, 95% CI 0.92-0.98; p = 0.004). Subgroup analyses suggested that the association was more evident among individuals aged 50-64 years, females, and residents of the central and eastern regions. CONCLUSIONS: Regular dental scaling may be associated with a modest reduction in the risk of dementia, particularly in individuals aged 50-64 years and in females. Although the association was statistically significant, the observed effect size was modest and should be interpreted cautiously. Further prospective studies are needed to confirm these findings and investigate the underlying mechanisms.