Association between denture restoration for tooth loss and cognitive impairment: A systematic review and meta-analysis

PURPOSE: This study aimed to investigate the association between denture restoration and cognitive impairment through a meta-analysis and to assess the correlation between different degrees of tooth loss. STUDY SELECTION: Observational studies exploring the association between denture restoration and cognitive function were systematically searched across six databases from January 2000 to January 2024. Two researchers independently searched electronic databases and extracted relevant studies from all articles. RESULTS: This study included 24,252 participants from six observational studies. The risk ratio and 95% confidence interval (CI) were used to compare the risk of cognitive impairment. Participants who experienced tooth loss without dentures had a 1.27-fold (95% CI: 1.20-1.38) higher risk of cognitive impairment, whereas those with dentures had only a 1.01-fold (95% CI: 0.92-1.12) higher risk. In the dose-response analysis, the risk of cognitive impairment in the non-denture group increased by 1.009 times (95% CI: 1.006-1.012) for each tooth lost, whereas the denture restoration group showed a 1.003 times (95% CI: 1.000-1.006) increased risk. The years of follow-up and clinical measurement tools simultaneously explained this heterogeneity. CONCLUSIONS: This study provides detailed evidence of a potential association between denture restoration and a reduced risk of cognitive impairment. Furthermore, there was a correlation between denture restoration and a reduced impact of the number of teeth lost on the risk of cognitive impairment. Therefore, timely and reasonable denture restoration may contribute to prevent cognitive impairment.