To explore the effects of tooth loss and denture use on cognitive impairment in the elderly.

Based on the data of China Health and Retirement Longitudinal Study (CHARLS), over 60-year-old elderlies were selected as the research subjects.Logistic regression was conducted to explore the effects of tooth loss, denture use on cognitive impairment in elderly and subgroup analysis, and interaction analysis were performed for gender and social participation.

A total of 4 372 elderly people were enrolled, and the rate of cognitive impairment was 16.20% (709/4 372). Older age, female, rural living, lower education, no spouse, with depressive symptoms, and without social-participation are risk factors for cognitive impairment. Group of non-total tooth loss without dentures (OR=1.382; 95% CI: 1.145-1.669) and group of total tooth loss without dentures (OR=2.074; 95% CI: 1.186-3.627) were associated with an increased risk of cognitive impairment. The results of subgroup analysis showed that the male population with non-total tooth loss and no dentures (OR=1.413; 95% CI: 1.077-1.853), with total tooth loss and no dentures (OR=2.600; 95% CI: 1.263-5.352) was still associated with an increased risk of cognitive impairment, while the female with non-total tooth loss and no dentures (OR=1.363; 95% CI: 1.046-1.776) was significantly associated with an increased risk of cognitive impairment.The non-social-participation-group with non-total tooth loss and no dentures (OR=1.475; 95% CI: 1.123-1.937), with total tooth loss and no dentures (OR=2.720; 95% CI: 1.294-5.715) were associated with an increased risk of cognitive impairment.There was no interaction between tooth loss, denture use, genderand social participation in the incidence of cognitive impairment(P>0.05).

The combination of tooth loss and denture use is an independent influence factor for cognitive impairment. The use of dentures can reduce the adverse effects of tooth loss on cognitive dysfunction, especially for those with partial tooth loss. The elderly should be encouraged to retain natural teeth, restore missing teeth in time. Although there is no interaction between tooth loss, denture use and social participation, older adults are suggested to take part in social activities.