STUDIES in a Colgate clinical research programme have shown that toothpastes containing zinc or stannous and mouthwash formulas with cetylpyridinium chloride (CPC) can neutralise the virus that causes COVID-19 by 99.9 percent.

According to a press release from Colgate, this research programme includes clinical studies among infected people to assess the efficacy of oral care products in reducing the amount of the virus in the mouth, potentially slowing the transmission of the COVID-19 virus.

During the laboratory studies, Colgate Total and Meridol toothpastes were the first to neutralise 99.9 percent of the virus after two minutes of contact. Colgate mouthwashes Plax and Total were similarly effective after 30 seconds. Completed in October, the studies were conducted in partnership with Rutgers New Jersey Medical School’s (NJMS) Public Health Research Institute and Regional Biosafety Laboratories.

“We’re at the early stages of our clinical investigations, but our preliminary laboratory and clinical results are very promising,” said Dr Maria Ryan, Colgate’s chief clinical officer, in a press release. “While brushing and rinsing are not a treatment or a way to fully protect an individual from infection, they may help to reduce transmission and slow the spread of the virus, supplementing the benefit we get from wearing masks, social distancing and frequent hand washing.

“Colgate is collaborating with numerous investigators throughout the globe to conduct clinical research to explore the potential of oral care products to reduce oral viral loads as a risk reduction strategy. We think oral care has a role to play in fighting the global pandemic, alongside other preventive measures.”

The programme’s results show that some toothpastes and mouthwashes may assist with reducing the spread of SARS-CoV-2, the virus that causes COVID-19, by temporarily reducing the amount of virus in the mouth. COVID-19 spreads through respiratory droplets or small particles produced when an infected person coughs, sneezes, sings, talks, or breathes, according to the US Centres for Disease Control and Prevention.

Dr David Alland, chief of infectious diseases and director of the Center for COVID-19 Response and Pandemic Preparedness, who led the Rutgers NJMS study along with colleagues Drs. Pradeep Kumar and Riccardo Russo, explained how the virus works and how it can be deterred by dental hygiene products.

“Given that saliva can contain amounts of virus that are comparable to that found in the nose and throat, it seems likely that SARS-CoV-2 virus originating in the mouth contributes to disease transmission, especially in persons with asymptomatic COVID-19, who are not coughing,” he said. “This suggests that reducing virus in the mouth could help prevent transmission during the time that oral care products are active.”

Colgate sponsored a clinical study, concurrent to the laboratory study, which involves some 50 hospitalised subjects with COVID-19. This study demonstrated the ability of three Colgate mouthwashes to drastically reduce the amount of the virus in the mouth on a temporary basis.

Dr Mark Wolff, Morton Amsterdam Dean of Penn Dental Medicine at the University of Pennsylvania, is excited about the research’s results.

“With this pandemic, the more we understand about the virus, the more effective we can be in fighting it, so I am excited to see the impressive research programme Colgate has undertaken,” Dr Wolff said. “We need to continue to take the precautions recommended by health authorities, and with these studies we may demonstrate an additional way to address the transmission of disease among people in close contact, particularly in dental practice. That would be an important advance.”