Reports & Studies

Regular tooth brushing reduces the risk of stroke!

PD Dr. Kristina Bertl, PhD MSc MBA

‘Tooth brushing and risk of stroke’ – are the two really connected? This hypothesis is based on the following theory: Poor and insufficient oral hygiene can lead to gingivitis and, in turn, to periodontitis. In periodontitis, oral bacteria can enter the bloodstream, resulting in a local and systemic inflammatory reaction. This inflammatory reaction is accompanied by an increase in inflammatory markers, and it is this mechanism that could in turn increase the risk of having a stroke.

In a recently published study, a research group from Korea presented the data of more than 200,000 participants. In a follow-up period of approximately 10 years, 7337 of these participants had a stroke.

The researchers investigated the following parameters and their possible connection to having a stroke:

  • Frequency of tooth brushing
  • Regular visits to the dentist
  • Oral hygiene sessions
  • Rate of tooth loss
  • Number of areas of caries

Statistical analysis of these data revealed some extremely interesting results:

  • Participants who brushed their teeth frequently (two to three times daily or more often) had a 10–20% lower risk of stroke than participants who cleaned their teeth a maximum of once daily.
  • Participants who had a high rate of tooth loss (8–14 or 15 and more teeth lost) had a 20–30% higher risk of having a stroke than participants who had not lost any teeth.
  • Participants who had four or more teeth with caries had a 20–30% higher risk of having a stroke than participants who had no caries.

This study shows once again that the mouth should not be regarded as separate from the rest of the body. Inflammation in the oral cavity can definitely have negative impact on serious systemic diseases.


Chang Y, Woo HG, Lee JS, Song TJ. Better oral hygiene is associated with lower risk of stroke. J Periodontol. 2021;92:87–94.