Experiments have shown that mouthwash can quickly kill coronaviruses, the school said, but there’s no evidence that it can prevent the virus from infecting people. The school is investigating how well mouthwash works to reduce the amount of coronavirus in the mouths of those with COVID-19 and if it can reduce the chance of spreading the virus to others.
The focus of the research will be to find a way to reduce the risk of coronavirus transmission in situations where masking and being more than six feet apart might not be an option, such as during dental procedures.
“While we are excited about the benchtop data, the true test is whether these mouthwashes have an effect on saliva in patients’ mouths and whether a mouth rinse could reduce the risk of SARS-CoV-2 transmission through oral droplets,” said principal investigator Laura Jacox, an orthodontist and oral health sciences researcher who is director of the Orthodontic Research Program at the Adams School of Dentistry.
Specifically, researchers plan to measure how much virus is found in saliva before and after using mouthwash according to the directions on the label. Adults who have tested positive for COVID-19 within the past seven days are eligible to participate in the clinical trial.
Because the mouth continually makes saliva, samples will be collected and tested every 15 minutes for up to an hour to track how long any reduction in viral load and infectivity lasts. The clinical trial will test commercially available mouthwashes that include common antiseptic ingredients such as cethylpyridinium chloride or ethanol.
“The study will allow us to determine which active ingredient in mouthwash has the most promise,” Jacox said. “Ideally it is an ingredient that is already FDA approved so it can go into use immediately.”
If proven effective, mouthwash could be a tool in controlling the spread of COVID-19 at one of the body’s primary points of coronavirus entry and transmission, the school said. Preliminary results of a study led by the Adams School of Dentistry and the National Institutes of Health showed that the salivary glands, tongue, and tonsils in particular are vulnerable to coronavirus infection.
COVID-19 commonly spreads during close contact when an infected person coughs, sings, talks, or sneezes, the school said.
“Using a mouth rinse is an easily implementable intervention that is low risk, inexpensive, and holds the potential for high reward,” said Jennifer Webster-Cyriaque, professor at the Adams School of Dentistry and the Department of Microbiology and Immunology at the UNC School of Medicine.
“The potential benefit can reach far beyond dental care to educational settings and places of worship and help essential workers when close contact is unavoidable,” Webster-Cyriaque said.