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Person brushing teeth.

Dental care can have an impact on the brain

Oral diseases starting with gingivitis double the risk of stroke already in working-age people, while intact molars can help keep the mind sharp.

  • Text Ulla Kaltiala | Photos Raija Törrönen and Mostphotos

In Finland, an oral disease more common than even tooth decay is periodontitis, which affects over 60 percent of the adult population. It is an inflammatory disease of the tooth-supporting tissue, with early symptoms including inflammation of the gum, and bleeding from the gum when brushing or flossing. Plaque and calculus accumulating on the surface of the teeth contribute to the development of periodontitis.

Advanced periodontitis can lead to the loosening and loss of teeth, but it can also significantly increase the risk of many other serious diseases by maintaining low-grade inflammation. “Inflammation can spread from the mouth to other parts of the body. Inflamed gums are also a gateway through which bacteria from the mouth can enter the bloodstream,” Professor of Translational Dentistry Pirkko Pussinen says.

The mouth harbours the second richest microbiome of the human body, i.e., a community of micro-organisms such as bacteria, yeasts and viruses – only the gut has more. In a healthy mouth, the microbiome is balanced, but in periodontitis, this balance is disturbed, and harmful bacteria take over. “These bacteria feed on the tissue destroyed by inflammation, and their proliferation, in turn, accelerates inflammation, creating a vicious cycle.”


The oral microbiome can still be restored to a healthy state by treating gingivitis, but not after it has advanced to periodontitis.

Pirkko Pussinen

Pirkko Pussinen.

The loss of molars increased the risk of dementia, and the risk was greater the more pairs of opposing molars were missing from the upper and lower jaw.

Sam Asher

Sam Asher.