NDCS-led study finds that keeping your teeth could add years of independent living

• The first Singapore-based study to estimate how the number of natural teeth impacts the years of life lived without limitations in daily activities or physical function among older adults.
• The biggest benefits were observed among men and those with primary or lower education, suggesting that poor oral health may contribute to inequalities in ageing outcomes.

A study led by the National Dental Centre Singapore (NDCS), in collaboration with researchers from Duke-NUS Medical School, has found that maintaining more natural teeth is associated with significantly additional years of independent living among older adults, especially among those who do not use removable dental prostheses.

The study, published in the Journal of Epidemiology and Community Health, assessed how tooth retention influences the number of years lived with and without limitations in daily activities (Activities of Daily Living [ADLs], such as bathing, dressing and eating and physical function such as walking and climbing stairs).

Specifically, the study found that among older adults who did not use removable dental prostheses, those who retained 20-32 natural teeth experienced substantially longer periods of independent living compared to those with no natural teeth[1]:

·       At age 60: more than 5 additional years without ADL limitations and more than 3 additional years without physical function limitations

·       At age 70: more than 4 additional years without ADL limitations and 2.5 additional years without physical function limitations

·       At age 80: more than 2 additional years without ADL limitations and over 1 additional year without physical function limitations

Professor Marco Peres, NDCS’ Deputy Chief Executive Officer, Research, Innovation and Education, and senior co-author of this research who led the oral health-related analysis, explained: "Our findings suggest that good oral health is not only about having a nice smile—it is essential to supporting our physical function, independence, and overall well-being in older age. This research highlights the importance of both tooth retention and prosthetic rehabilitation, which can add more meaningful years of healthy, independent living and in promoting healthy ageing."

The research also highlighted the role of removable dental prostheses in supporting healthy ageing, particularly when tooth loss is unavoidable. Among prosthesis users with secondary or higher education, those with 20-32 natural teeth experienced more years without ADL limitations, while those with 10-19 natural teeth experienced more years without physical function limitations, compared to those with no natural teeth.

These findings were concluded from a nationally representative longitudinal survey of more than 3,000 Singaporeans aged 60 and above[1], reinforcing the importance of maintaining natural dentition for as long as possible. Retaining more teeth may be associated with more years of independent living, without limitations in ADLs or physical function. Removable dental prostheses may partially mitigate the effects of tooth loss.

The research adds to increasing evidence that oral health plays a crucial role in overall wellbeing and quality of life in older age. The findings suggest that investing in preventive dental care, tooth retention strategies and access to removable dental prostheses could yield significant benefits for healthy ageing at both individual and population levels.

Assoc. Prof. Rahul Malhotra, senior co-author of this research, said, “This study shows that oral health is closely linked to how long people can remain independent as they age. We found that the benefits of retaining more natural teeth—particularly among those who do not use removable dental prostheses—were more pronounced among men and participants with lower levels of education. This suggests that oral health may play an important role in shaping inequalities in ageing outcomes. It also highlights the importance of tooth retention and equitable access to appropriate dental care, not just for clinical outcomes, but for healthy ageing more broadly.”

With Singapore’s rapidly ageing population, the study provides timely evidence for policymakers, clinicians, patients and caregivers. Promoting tooth retention, improving access to prosthetic solutions, and encouraging regular dental check-ups may help older adults maintain their independence and quality of life for longer.