Toothpastes that include zinc or stannous and mouthwash formulas with cetylpyridinium chloride (CPC) neutralize SARS-CoV-2 by 99.9%, according to Colgate, which conducted clinical studies among infected people to assess the efficacy of oral care products in reducing the amount of the virus in the mouth and potentially slowing its transmission.
In the studies, which Colgate said were the first to include toothpaste, Colgate Total and Meridol toothpastes neutralized 99.9% of the virus after two minutes of contact. Colgate Plax and Colgate Total mouthwashes were similarly effective after 30 seconds.
The results suggest that some toothpastes and mouthwashes may help reduce the spread of SARS-CoV-2, which causes COVID-19, by temporarily reducing the amount of virus in the mouth. The virus spreads through respiratory droplets or small particles produced when an infected person coughs, sneezes, signs, talks, or breathes.
“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.
“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,” Ryan said.
“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,” said Dr. David Alland, leader of the study and chief of infectious diseases and director of the Center for COVID-19 Response and Pandemic Preparedness.
“This suggests that reducing virus in the mouth could help prevent transmission during the time that oral care products are active,” Alland said.
Concurrent to the laboratory study, Colgate sponsored a clinical study involving some 50 hospitalized subjects with COVID-19 demonstrating the ability of Colgate Total (with CPC and zinc), Colgate Peroxyl, and Colgate PerioGard mouthwashes to substantially reduce the amount of virus in the mouth temporarily.
Additional Colgate-supported clinical research studies on toothpaste and mouthwashes are in the early stages at the Rutgers New Jersey Medical School, the Albert Einstein Institute in Sao Paulo, Brazil, and at the University of North Carolina at Chapel Hill Adams School of Dentistry, with some 260 people with COVID-19 participating.
“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,” said Ryan. “We think oral care has a role to play in fighting the global pandemic, alongside other preventive measures.”
“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 program Colgate has undertaken,” said Dr. Mark Wolff, Morton Amsterdam Dean of Penn Dental Medicine at the University of Pennsylvania.
“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,” Wolff said.