Study finds coronaviruses 'inactivated' by mouthwash, but what does that really mean?

A new study conducted by researchers at the Penn State College of Medicine has found that a common dental item can inactivate human coronaviruses -- mouthwash and oral rinses.

DES MOINES, Iowa (WHO) -- A new study conducted by researchers at the Penn State College of Medicine has found that mouthwash and oral rinses can inactivate human coronaviruses.

Products like Listerine or Crest Pro Health mouthwashes were found to inactivate 99.9% of the coronavirus called 229E that causes common colds.

The study did not investigate SARS-CoV-2, the new coronavirus that has killed over 225,000 Americans. According to The New York Times, while the two viruses are similar, they should not be considered interchangeable.

Infectious Disease Specialist Dr. Rossana Rosa said those looking for a quick fix may be disappointed. Using these rinses to actually prevent contracting coronavirus may not be possible.

"If you are infected with COVID and you are in that phase where the virus is replicating within certain parts of your body, that is not something that happens once. That is actually something that happens over a few number of days," Rosa said. "So if you indeed gargle mouthwash and you kill some of the virus that's in there, that doesn't mean that that was all that COVID that you had in your body."

Rosa said though such studies are useful for exploring possible solutions to the pandemic, for now, it's best to use mouthwashes to protect from things like gingivitis and use masks and social distancing against COVID-19.

"I think it's important as new information comes in that one assesses it and see how reasonable it is. We certainly have to be humble, we all remember that at some point we really thought that face cloth masks would not really work," Rosa said. "Now, more evidence has come out showing that it actually works. So I do think that if something new comes up, it's important that you see where is it published, is it a reputable journal, you know, talk to your provider about the strength of that evidence."

Items tested in the study were 1% solution of baby shampoo, a neti pot, peroxide sore-mouth cleansers and mouthwashes.