Association between restoration of missing teeth with dentures and cognitive function

Abstract

A commentary on: Ma X, Zhang Y, Wang J et al. Association between denture restoration for tooth loss and cognitive impairment: a systematic review and meta-analysis. J Prosthodont Res 2025; https://doi.org/10.2186/jpr.JPR_D_24_00060 .

Data sources: A search was conducted across five electronic databases, including PubMed, EMBASE, Cochrane Library, MEDLINE, and CNKI, from January 2000 to January 2024. The search strategy included keywords related to tooth loss, dentures, cognitive function, memory loss and dementia. Reference lists of relevant studies were also screened to identify additional articles. The search was limited to the English language only.

Study selection: Observational studies examining the association between denture restoration and cognitive impairment were included. Eligible studies had to report cognitive impairment or dementia as the outcome and denture restoration as the exposure factor. Six studies with a total of 24,252 participants met the inclusion criteria.

Data extraction and synthesis: Two independent reviewers extracted relevant data, including study design, participant characteristics, dental status, cognitive assessment methods, and statistical results. Meta-analysis was conducted using risk ratios (RR) with 95% confidence intervals (CI), applying a random-effects model due to clinical and methodological variations. Newcastle-Ottawa Scale and the Agency for Healthcare research and quality scale were used for quality assessment of included studies. Beg- Mazumdar and Egger regression tests were used to assess the publication bias.

Results: The meta-analysis revealed that participants with tooth loss without dentures had a 1.27-fold higher odds of having cognitive impairment, whereas those with dentures had only a 1.02-fold odds. A dose-response analysis showed that each additional missing tooth increased the cognitive impairment risk by 1.009 times in the non-denture group, while the denture group exhibited a lower risk increase of 1.003 times. Heterogeneity was influenced by follow-up duration and cognitive assessment tools. There was significant evidence of publication bias in non denture group as compared to the denture restoration group which showed nonsignificant evidence of publication bias.

Conclusions: This study suggests denture restoration is associated with a reduced risk of cognitive impairment in individuals with tooth loss. The findings highlight the potential protective role of timely denture rehabilitation in mitigating cognitive decline. Future research should focus on longitudinal and interventional studies to establish causality.