Tooth loss, dental prosthesis use, and cause-specific mortality in older Japanese adults: a 7-year cohort study

Poor oral health, particularly tooth loss, is associated with increased risk of all-cause mortality. However, the impact of dental prosthesis use on these associations remains unclear. This study evaluated the relationship between the number of remaining teeth, dental prosthesis use, and mortality from specific causes using seven-year follow-up data from the Japan Gerontological Evaluation Study (JAGES). All-cause mortality and ten cause-specific mortality outcomes were assessed. The number of remaining teeth and use of dental prostheses were the main exposures. Cox proportional hazard models were used to estimate hazard ratios (HRs). Among 43,774 participants (mean age 73.7 years [SD 5.9]; 53.2% women), 5,707 (13.0%) died during follow-up, corresponding to 20.7 deaths per 1,000 person-years. Participants with 0-9 or 10-19 teeth without dental prostheses exhibited higher cause-specific mortality rates than those with ≥ 20 teeth. Specifically, those with 0-9 teeth without dental prostheses had a significantly elevated risk of mortality from cancer, cardiovascular disease, respiratory disease, and injury (HRs ranging from 1.31 to 1.91; all p < 0.05). These associations were attenuated among dental prostheses users. Tooth loss was associated with increased risk of mortality from multiple specific causes; however, dental prostheses may mitigate this risk.