Brush your teeth properly, clean between your teeth once a day, and replace missing teeth promptly

Moderate value
Evidence B
Buys life
Disputed
Costs a little
Takes minutes
Some willpower

In plain words

People who use floss or interdental brushes every day have about a 10% lower chance of dying over the same period. Older people who have lost all their teeth have about a 90% higher chance. Those with fewer than 20 teeth have about double. Electric toothbrushes remove 10% to 20% more plaque than manual ones and leave gums somewhat less inflamed, but how much that difference matters is still unclear.

Cost: Floss or interdental brushes cost a few dozen CNY a year, and a dental cleaning costs a hundred or two each time. It adds two or three minutes a day. The hard part is making cleaning between your teeth a daily habit. If a manual toothbrush doesn't get your teeth clean, you can switch to an electric one, a few hundred CNY a brush, with the brush head replaced regularly.
What you get: A Japanese study followed 9676 people for 6 years. People who used interdental cleaning tools had about 11% lower risk of death (hazard ratio 0.89). Those who used a tongue cleaner had about 23% lower (0.77). In addition, pooled studies of older people living in the community found that people with no teeth at all had about 1.87 times the odds of death (odds ratio, 95% CI 1.35–2.59, the plausible range). Those with fewer than 20 teeth had about 2.04 times (1.67–2.49). Electric versus manual: pooling 51 randomized trials, after 1 to 3 months of use the electric brush left about 11% less plaque, and after more than 3 months about 21% less. Gum inflammation was about 6% and 11% milder. The review authors say it is unclear how much these differences matter for health
Notes: Disputed. These studies only followed people. People with bad teeth often have poorer overall health and finances too, and it is hard to say whether the teeth dragged down the body or poor health dragged down the teeth. But this costs very little, and gum disease and missing teeth affect eating on their own. Among electric brushes, the round-headed type whose head rotates back and forth has the most trials and the most certain effect against manual brushing. Which type of electric brush is better than another, independent reviews did not conclude, because there are too few trials. For what an implant costs and which dental services insurance covers, see §24.12 (ask for an all-inclusive price before getting an implant)
Evidence grade: B : Supported by research but without a precise number, or based on small or single studies.
Sources: Wang K, Matsuyama Y, Kiuchi S, et al. (2026). Routine oral health practices and all-cause mortality. Journal of Dentistry. https://doi.org/10.1016/j.jdent.2026.106789
Ko MJ, Seo S, So JS, et al. (2026). Deteriorated oral health and function as risk factors for physical disability and mortality in community-dwelling older adults: a systematic review and meta-analysis. European Geriatric Medicine. https://doi.org/10.1007/s41999-025-01319-4
Yaacob M, Worthington HV, Deacon SA, et al. (2014). Powered versus manual toothbrushing for oral health. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD002281.pub3
Deacon SA, Glenny AM, Deery C, et al. (2010). Different powered toothbrushes for plaque control and gingival health. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD004971.pub2

Mentioned in

Before getting a dental implant, ask exactly what the package price includes, look first at providers that have committed to price controls, and don't trust low-price ads

Translated from the Chinese original. Original book, section 2, tip 10. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer