Does Mouthwash Actually Do Anything?

Does Mouthwash Actually Do Anything?
Photo: Ju Jae-young, Shutterstock

After brushing and flossing, mouthwash completes the trifecta of daily dental care. But do we really need all three steps? Dentists wouldn’t dare tell you to skip flossing or brushing, but it turns out they’re a lot more equivocal about mouthwash.

Where did mouthwash even come from?

Mouthwash, which is more technically known as “mouthrinse,” arguably got its start as one of many uses for the surgical disinfectant Listerine. In the late 1800’s, Joseph Lister figured out that carbolic acid could be used to keep surgical tools and wounds clean, and that patients were a lot less likely to die as a result. A few years later, he allowed his name to be used for a different antiseptic, one made of a combination of essential oils. That was Listerine.

Early ads were directed at doctors and described the many things one could sanitize with it, both inside and outside of the body. (I kept coming across claims that the stuff was originally intended as a floor cleaner, but can’t confirm that it was ever marketed for that specific use.)

Eventually, the Listerine company figured out a new way to market the stuff, and ran ad after ad for the general public playing up the dreadful problem of halitosis and promising that rinsing your mouth regularly with Listerine could treat it or even prevent it from happening in the first place. Halitosis, despite the sciencey-sounding name, just means bad breath. It’s not recognised as a medical condition.

What do dentists think of mouthwash today?

The American Dental Association points out that there are actually two types of mouthrinse: cosmetic and therapeutic.

A lot of your typical drugstore stuff is cosmetic. Here’s what the ADA has to say about it:

Cosmetic mouthrinses may temporarily control bad breath and leave behind a pleasant taste, but have no chemical or biological application beyond their temporary benefit. For example, if a product doesn’t kill bacteria associated with bad breath, then its benefit is considered to be solely cosmetic.

That’s right: Making your mouth feel fresh and clean is the whole point of a cosmetic mouthrinse. It’s not a side effect of some bacteria-blasting power.

So what about therapeutic mouthrinses? The ADA has a list of products that have earned their seal of approval, which include mouthwash products that either contain fluoride or have been shown to kill specific mouth-dwelling bacteria. Speaking more generally, they list a few active ingredients that actually do something:

Cetylpyridinium chloride may be added to reduce bad breath.4 Both chlorhexidine and essential oils can be used to help control plaque and gingivitis.4, 5 Fluoride is a proven agent in helping to prevent decay.7 Peroxide is present in several whitening mouthrinses.1

So should you use it? If your dentist recommends a specific type for a specific reason, follow their recommendations (and their instructions for when and how to use it). I’ve been prescribed chlorhexidine mouthwash in the past, and told to use it for just a few weeks for a specific issue I was having. My current dentist is a fan of fluoride mouthwash and suggested I use it nightly.

But in general? Mouthwash is “not a necessary step to maintain good oral health,” an ADA spokesperson told us last time we started asking detailed questions about how to use it. So keep using your mouthwash if it’s a dentist-recommended product or if you simply like that fresh and clean feeling. Otherwise, feel free to drop it from your routine.

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