Related Experiment Video
Updated: Apr 18, 2026

Oral Health Assessment by Lay Personnel for Older Adults
Published on: February 2, 2020
Association Between Change in Dental Hygiene Practices and Incidence of Dementia
Sangwoo Park1, Jonghyeok Lee1, Sun Jae Park1
1Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea.
Aim:
To investigate whether changes in toothbrushing frequency influence the incidence of dementia.
Materials And Methods:
This is a retrospective cohort study using the Korean National Health Insurance Service database. Among 91,978 adults who received two oral health screenings between 2002 and 2005, 74,156 were included after exclusions. Participants were followed until 2019. Participants were categorised into nine groups based on toothbrushing frequency (≤ 1, 2, ≥ 3 times/day) at each screening. Main outcomes such as incidence of overall dementia, Alzheimer's disease (AD) and vascular dementia (VaD) were assessed using Cox proportional hazards models, adjusting for potential confounders.
Results:
Individuals who increased their toothbrushing frequency to ≥ 3 times/day showed reduced risks of overall dementia (aHR 0.79, 95% CI 0.64-0.99) and AD (aHR 0.76, 95% CI 0.59-0.96). Those who decreased their brushing to ≤ 1 time/day had a higher risk of AD (aHR 1.31, 95% CI 1.05-1.65). A decrease from moderate brushing frequency was associated with elevated VaD risk (aHR 1.32, 95% CI 1.02-1.70).
Conclusion:
Improvements in dental hygiene practices may lower dementia risk, even among those with poor baseline habits. Conversely, lapses in oral care among previously consistent brushers may increase dementia risk.
Related Concept Videos
Dementia
The progression of dementia is generally gradual....
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Alzheimer Disease l: Introduction
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Dementia l: Introduction
The Oral Microbiota

