The Truth About Whether Toothbrushing Can Protect Against Covid

A dental expert has suggested brushing your teeth more often could be used as a preventative measure against Covid-19, in a similar vein to hand-washing.

Professor Martin Addy, a dentistry professor at the University of Bristol, said toothpaste contains the same detergents as those found in soap and hand wash gels, which could help prevent the virus behind Covid-19 from making itself too comfortable in your mouth.

“The antimicrobial action of toothpaste in the mouth persists for three to five hours and, thereby, would reduce the viral load in saliva or infection by viruses entering the mouth,” he reportedly told The Telegraph.

Prof Addy suggested people should brush their teeth before going out. “For the vast majority, the timing of tooth brushing should be focused when they are about to go out of their homes for exercise or shopping,” he said. “Ideally, tooth brushing frequency should be increased.”

Prof Addy has been keen to spread the word on toothbrushing against coronavirus for some time now. In April, he wrote a letter, published in the British Dental Journal, asking why the profession has not been promoting oral hygiene, through toothbrushing, in the preventive approach to Covid-19.

“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 his letter.

“Although, we may assume such oral hygiene practices are already the norm, this is certainly not the case, particularly for those individuals who coincidentally are most at risk of contracting Covid-19.”

While brushing your teeth often is obviously not a bad thing – and is great for overall health – Professor Paul Hunter, of the Norwich School of Medicine at the University of East Anglia, believes the claim it could be used as a protective measure against Covid-19 is “pushing it a bit far”.

“Whilst I cannot say for certain there would be no effect whatsoever, I do not think it likely that teeth brushing would make that much difference,” he tells HuffPost UK.

Prof Hunter points out that droplets can (and do) infect through the nose, and can be inhaled directly to the back of the throat, deeper into the respiratory tract – “so any residual disinfection around the teeth is very unlikely to have much, if any, benefit,” he says. 

“The other issue,” he adds, “is that viruses are intracellular pathogens and once taken into a cell are protected from any surface disinfection, so any disinfectant would have to kill a virus very quickly before the virus is taken into a cell.”

Proving that regular brushing of teeth does or does not protect against Covid-19 “would be very difficult”, he adds. 

Results from cell culture experiments show some commercially available mouthwashes can “deactivate” the virus. Researchers said such mouthwashes should not be used to treat Covid, but it could be used as a preventative measure before dental treatments, for example.

“Gargling with a mouthwash cannot inhibit the production of viruses in the cells,” said study author Toni Meister, of Ruhr University Bochum, “but could reduce the viral load in the short term where the greatest potential for infection comes from, namely in the oral cavity and throat – and this could be useful in certain situations, such as at the dentist or during the medical care of Covid-19 patients.”