Can brushing your teeth prevent the spread of COVID-19? Not exactly
Philippe Hujoel, a dentist and University of Washington professor, holds a toothbrush and toothpaste as he poses for a photo in an office at the school in Seattle on Friday, Aug. 3, 2018. (Elaine Thompson / The Associated Press)
TORONTO -- A U.K. dental expert has suggested that frequent tooth brushing could be used as a preventative measure against COVID-19 in a similar vein to hand washing, a claim Canadian experts say is unfounded but may have some truth.
Speaking to The Telegraph, Martin Addy, a dentistry professor at the University of Bristol, claimed that the antimicrobial action of toothpaste in the mouth may reduce the viral load of COVID-19 in saliva, even suggesting that it may prevent infection by viruses entering the mouth.
Addy likens the effect to that of washing your hands with soap or hand sanitizer.
“The majority, if not all toothpastes, contain detergents, which confer significant antimicrobial properties to the product, indeed the same detergents are present in many hand washing formulations, recommended against coronavirus,” he wrote in April in a letter published in the British Dental Journal calling on experts to promote good oral hygiene amid the pandemic.
According to the World Health Organization, COVID-19 spreads from an infected person’s mouth or nose in small liquid particles referred to as “respiratory droplets” when the person coughs, sneezes, speaks, or breathes heavily.
With that in mind, theoretically, Addy’s suggestion makes sense.
“Theoretically, it makes sense that brushing your teeth or washing your mouth could reduce the risk of catching COVID-19 because we know that the main infection is occurring through the mouth and nose,” Dr. Liran Levin, head of the periodontology division at the Faculty of Medicine and Dentistry, University of Alberta, told CTVNews.ca by phone Tuesday.
But Levin notes there is no study to show that brushing your teeth will decrease the coronavirus load in the oral cavity.
“It’s very difficult to get a good answer whether this is some protective measure that should be recommended,” he said while noting there is no harm in brushing your teeth once or twice more a day if you feel so inclined.
Similarly, the Canadian Dental Association (CDA) says these claims are nothing more than theoretical.
“Most dental products are anti-microbial in nature, that’s what they’re designed to do, and so they would reduce certain bacterial loads for sure,” Dr. Aaron Burry, associate director of professional affairs at the CDA, told CTVNews.ca by phone Tuesday.
“Toothpastes are largely detergents and we know that detergents, just like hand washing, is effective in reducing viral loads. But for how long and is that of consequence to COVID, I don’t think is possible to say.”
Some experts note that using antiseptic mouthwash may help reduce the risk of spreading COVID-19 should you be infected. But, again, there is little research to prove such claims.
Levin notes that at the University of Alberta’s dental school, patients are now required to use a mouthwash before undergoing exams because of the “perception” that it may reduce the viral load, he says.
Kal Khaled, president of the Ontario Alliance of Dentists, says there is some evidence that mouthwash can reduce the viral load in the mouth, but notes it’s unclear how long the effect lasts.
“For a period of time you may be less likely to infect others [through your saliva]. The question is for how long… it could be 20 minutes, it could be 30 minutes, it could be an hour. But it will come back,” Khaled told CTVNews.ca by phone Tuesday.
The CDA recommends that Canadians keep up with their oral health care amid the ongoing pandemic, including regular use of things like toothpaste that help control the bacteria in the mouth to prevent cavities and periodontal disease.