Cavity-Prone? A Dentist Explains Why You Should Be Careful About Mouthwash

The rules of good dental hygiene are pretty simple: brush and floss at least twice a day and use mouthwash when you want to freshen up. But not all mouthwashes are created equal. And if you’re consistently using the wrong type of mouthwash, it might actually hurt your overall dental health. It might be time to consider an alcohol-free mouthwash.

Generally, using mouthwash is a great idea. “Especially when you don’t have time to brush your teeth and you’ve eaten a meal or snack,” Inna Chern, DDS, a dentist in New York City, tells Well+Good. “It helps to mechanically remove food particles and bacteria from the mouth.” Like floss, mouthwash can get in between your teeth, reaching food particles your toothbrush can’t get to. But some mouthwashes remove too many bacteria, killing the good along with the bad. And some are too acidic.

There are two categories of mouthwash: therapeutic and cosmetic, according to the American Dental Association (ADA). Therapeutic mouthwashes have active ingredients that target bad bacteria and reduce plaque, gingivitis, and cavities. Cosmetic mouthwashes, however, just temporarily freshen your breath and leave you with a minty taste but don’t do squat for cavities or gum disease.

Many of the mouthwashes the ADA may consider cosmetic contain alcohol, which can dry out your mouth. That makes alcohol-based mouthwashes especially bad for people who are already prone to dry mouth, a condition dentists call xerostomia. Dry mouth isn’t just uncomfortable, it can also lead to tooth decay because saliva neutralizes acids and limits bacteria growth. Dry mouth may be a consequence of certain medications, radiation treatment, health conditions like diabetes or autoimmune conditions like HIV/AIDS, getting older, and even sleeping with your mouth open. Dr. Chern recommends that anyone who is prone to dry mouth use an alcohol-free mouthwash or a mouthwash specifically made for dry mouth such as Biotene.

Even if you don’t have dry mouth, alcohol-based mouthwashes aren’t the best choice. In fact, Harold Katz, DDS, founder of The California Breath Clinics, urges patients to never use an alcohol-based mouthwash. “Most are very acidic,” he says, adding that this can exacerbate dry mouth and oral health issues. “Look for mouthwashes with a pH over 7, which are also non-alcohol.”

Acid is a tooth’s enemy. Cavities happen when acids in your mouth wear down the outer layer of your tooth, known as the enamel. Not all alcohol-free mouthwashes are on the base side of the pH scale, but many are, while many alcohol-based mouthwashes are acidic. So, if you’re prone to cavities, you’ll especially want to avoid an acidic mouthwash.

Another downside of alcohol-based mouthwash is that it’s too aggressive. “Aside from burning sensations, the alcohol in mouthwash completely destroys almost all the bacteria in your mouth. Both good and bad,” says Nammy Patel, DDS, a holistic dentist who practices in California. Although you may want to think the burning you feel with alcohol-based mouthwashes means it’s working, it actually means it’s overworking. Certain bacterias that live in the mouth protect your gums against the disease-causing bacteria, aid in digestion, and protect against harmful microbes in food, according to the National Institutes of Health.

If you’re looking for a good dental routine that includes the best mouthwash for gums, steer clear of alcohol-based rinses. All three of the dentists we spoke to listed alcohol as an ingredient to avoid. Dr. Patel also suggests staying away from chlorhexidine gluconate, an antiseptic that kills both good and bad bacteria as well, and methyl salicylate, a chemical added for flavor that some research has linked with reddening and irritation of the skin.

As for ingredients you should want in a mouthwash, Dr. Chern says to look for a mouthwash with either gingivitis or anticavity treatments, including fluoride. She recommends Tom’s of Maine’s Alcohol-Free Mouthwash but stresses that if you are prone to cavities, you try something with fluoride.

And, as always, remember to brush and floss regularly if you really want to fight off bad breath and cavities. Mouthwash can be a great part of a dental health routine, but it should never be your first defense.