Shopping for mouthwash has become an increasingly confusing affair. In drugstores you’ll find shelf after shelf of rinses that claim to prevent bad breath, fight cavities and plaque (the sticky material that contains bacteria), whiten teeth, reduce dry mouth and even provide “advanced care” or “total care.”
There are two basic types:
Cosmetic rinses for breath freshening: The Food and Drug Administration (FDA) regulates them minimally, and the American Dental Association (ADA) does not evaluate them.
Therapeutic rinses: The active ingredients kill bacteria and reduce plaque and thus help protect against gingivitis, a form of periodontal (gum) disease. Regulated by the FDA, they may apply for the ADA seal, which certifies that the product works as claimed. The only nonprescription mouthwash with the ADA seal is Listerine and its generics (labeled “antiseptic” rinses), as well as rinses containing fluoride.
Keep in mind: No mouthwash can take the place of thorough brushing and flossing and regular visits to the dentist. In fact, poor oral hygiene and periodontal disease are major causes of bad breath. If you practice good oral hygiene, you may not need a mouthwash at all.
A mouthful of ingredients
Alcohol: This antiseptic, found in most Listerine rinses and generics, has antibacterial activity and helps prevent and reduce gingivitis and plaque above the gum line. It can, however, cause a burning sensation and be drying. Some researchers are concerned that long-term use of products with alcohol may increase the risk of oral cancer, but the ADA says alcohol rinses are safe. The FDA also says the combination of ingredients in Listerine mouthwash is “generally recognized as safe and effective.” Still, if you have a history of oral cancer or risk factors for it, such as smoking, the ADA says it may be prudent to avoid such rinses.
Antibacterial enzymes: Bacteria can be killed by many agents, including enzymes made in the human body. Some products (Biotène, for instance) contain enzymes such as lysozyme and lactoperoxidase (found in saliva), which may help reduce dry mouth.
Cetylpyridinium chloride: An ammonium compound that kills bacteria and inhibits plaque formation, this is particularly good at eliminating bad breath.
Chlorhexidine: This is the best ingredient for fighting plaque and treating periodontal disease. But it is found only in prescription mouthwashes, such as Peridex. Prolonged use can stain teeth.
Detergents, such as sodium lauryl sulfate and sodium benzoate: Advanced Formula Plax, for example, designed for rinsing before brushing, has detergents that loosen plaque.
Essential oils, such as menthol and Eucalyptol: Used in alcohol-based rinses such as Listerine, these act as breath fresheners and also have an antibacterial effect.
Fluoride: Stannous or sodium fluoride helps prevent cavities. If your water is fluoridated and your toothpaste has fluoride, you don’t need a fluoride rinse unless you’re prone to cavities because, for instance, you have lots of crowns or bridges. Sold by prescription, stronger fluoride rinses such as Periomed are also used to decrease tooth sensitivity and gum inflammation. Children shouldn’t use fluoride rinse more than once a week, since it can discolor teeth.
Herbs and other “natural” ingredients, such as sanguinaria (bloodroot), echinacea, goldenseal, aloe and vitamin C: Sanguinaria kills bacteria, but has been linked with a risk of leukoplakia (a precancerous oral condition). Plant-derived ingredients that freshen breath or kill bacteria are no more “natural” than fluoride or alcohol.
Hydrogen peroxide: This has antibacterial properties and may help reduce plaque and gingivitis. It whitens teeth modestly, but may cause irritation if overused.
Zinc chloride: Combats bad breath. At least one brand, Smart Mouth, claims to work for 12 hours, though there’s only one small study to support this claim.
Four mouthwash strategies
- To freshen breath: Any mouthwash is fine for temporary breath freshening, though cetylpyridinium chloride and zinc chloride may have a longer effect.
- If you have frequent cavities: Your dentist may advise you to use a rinse with fluoride.
- To combat plaque and gingivitis: Choose a rinse with cetylpyridinium or essential oils. Prescription rinses with chlorhexidine are most effective. Alcohol kills bacteria, but because of the cancer concerns, the previous ingredients are preferable.
- For dry mouth: Biotène can help reduce dry mouth. Use on professional advice. Avoid rinses containing alcohol.
Final words: Mouthwashes work best if you brush and floss before using them. If you brush afterward, toothpaste may wash away or deactivate the ingredients. A tablespoon after brushing and flossing should do. Keep mouthwash out of the reach of children.