BACKGROUND: Previous studies show social inequality in tooth loss, but the underlying pathways are not well understood. The aim was to investigate the mediated proportion of sugary beverages (SBs) and diabetes and the association between educational level and tooth loss, and to investigate whether the indirect effect of SBs and diabetes varied between educational groups in relation to tooth loss.

METHODS: Data from 47,109 Danish men and women aged 50 years or older included in the Danish Diet, Cancer and Health Study was combined with data from Danish registers. Using natural effect models, SBs and diabetes were considered as mediators, and tooth loss was defined as having <15 teeth present.

RESULTS: In total, 10,648 participants had tooth loss. The analyses showed that 3% (95% confidence interval 2-4%) of the social inequality in tooth loss was mediated through SBs and diabetes. The mediated proportion was mainly due to differential exposure to SBs and diabetes among lower educational groups.

CONCLUSIONS: The findings show that SBs and diabetes to a minor degree contribute to tooth-loss inequalities. The explanation indicates that individuals in lower educational groups have higher consumption of SBs and more often suffer from diabetes than higher educational groups.