What should I look for in mouthwash?

Dear Alice,

I've been trying to take better care of my teeth lately (as a general health thing, not because my dentist says I'm in trouble or anything) and so I started using mouthwash after I brush. But I'm confused about what it actually does. If I get a kind with lots of alcohol (which bothers me) it seems like it's supposed to kill germs and keep bad breath away. But in the alcohol-free ones, there's a huge variety: freshening, fluoride, anti-plaque... What is the point of mouthwash supposed to be? What should I be looking for?

curious mouthwasher

Dear curious mouthwasher, 

Glad to see you’re looking to brush up on your oral hygiene, as it’s a key but frequently overlooked aspect of staying healthy! In fact, health care providers consider oral hygiene to be a reliable indicator of digestive, cardiovascular, and immune system health. As you may know, brushing and flossing are essential for helping rid the mouth of odor- and plaque-causing bacteria. If you’re looking to have a super clean mouth, you may want to try incorporating some tongue scraping or mouth swishing. You're right that different types of mouthwash target different oral hygiene concerns. Generally, they fall into two categories: therapeutic (antibacterial and antiseptic) and cosmetic (breath-freshening). Antibacterial and antiseptic mouthwashes usually have compounds that address the causes of bad breath, while breath-freshening mouthwashes only treat the symptoms. It’s good to know what these rinses do so that you’ll be able to pick a mouthwash that suits your needs. Read on for information that will help you navigate the dental hygiene aisle of any drugstore or supermarket like a pro! 

Antibacterial and antiseptic mouthwashes are the most effective at fighting gum disease, gingivitis, plaque, cavities, and bad breath by reducing the bacteria counts in the mouth through several different compounds. Additionally, antiseptic formulas often contain high percentages of alcohol and have quite a strong taste. While alcohol is a potent germicide, others find that it can dry and irritate the mouth. If the alcohol content in these types of mouthwashes is bothersome or undesirable for you, there are plenty of low-alcohol or alcohol-free options. Other common active ingredients in antibacterial and antiseptic mouthwashes include: 

  • Cetylpyridinium chloride combats bacteria, plaque buildup, and bad breath. 
  • Chlorhexidine is effective against plaque and gingivitis, but a prescription is necessary for it. Overuse may lead to tooth damage, such as staining. 
  • Hydrogen peroxide fights bacteria, plaque, and gingivitis, and may whiten teeth. Overuse may lead to irritation.  

Furthermore, therapeutic rinses are regulated by both the Food and Drug Administration (FDA) and the American Dental Association (ADA) — you’ll see an ADA seal on such products endorsed by the institution. For those with a history of oral cancer, the FDA gives alcohol-containing mouthwashes the green light, however the ADA advises against them.  

Breath-freshening mouthwashes are easier on the taste buds and have lower alcohol content than the stronger antibacterial and antiseptic options. Formulas containing chlorine or zinc work by defusing sulfur compounds produced by bacteria. Other products contain cetylpyridinium, and all natural brands rely on natural germ-fighting ingredients, such as witch hazel or grapefruit-seed extract instead of alcohol as antibacterial agents. These washes are good for those who have bad breath but not significant gum disease or tooth decay. Unless otherwise noted on the label, breath-freshening mouthwashes aren’t meant to prevent gingivitis, plaque, or tooth decay. 

Finally, if you’re cavity-prone, fluoride rinses may be a good option for you. These types of anti-cavity rinses coat the teeth with a protective film that strengthens tooth enamel and reduces risk for cavities. In the United States, fluoridated tap water is common. If you regularly drink water from the faucet, chances are you're getting adequate fluoride on your teeth already. However, those who drink bottled or filtered water may want to add a fluoride rinse to their routine. Fluoride has to remain on your teeth for about a half an hour to work, so if you pick this kind, it’s best to swish for a full minute and then avoid eating or drinking for a while afterward. No matter which type of mouthwash you choose, it’s a good idea to follow the instructions on the bottle. 

While it doesn't sound like you started using mouthwash in response to a problem, if you do find that you have persistent bad breath, you may want to consult a dental professional about other potential causes. Gum disease, tooth infection, cavities, poorly fitting crowns, and post-nasal drip are all possible causes of bad breath. Other culprits include certain foods, medications, cigarettes, and chewing tobacco, as well as infections in the tonsils or sinuses. In any case, if you’re not sure which mouthwash to use, it may be wise to talk with your dentist to figure out the best option for you. 

Wishing you a minty-fresh day, 

Last updated Sep 24, 2021
Originally published Feb 15, 2008

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