If You Have Bad Breath but Not Significant Gum Disease or Tooth Decay…Use: Breath-freshening mouthwash, which neutralizes odor. Studies have shown that chlorine and zinc, the primary ingredients in these rinses, defuse foul-smelling sulphur compounds produced by bacteria. Some products, like Scope, also contain a germicide called cetylpyridinium, which has antigingivitis (gum disease-fighting) and antiplaque benefits, says Clifford Whall, Ph.D., the director of the American Dental Association (ADA) Seal of Acceptance program. Plus, breath-freshening mouthwashes are easier on the taste buds than Listerine and have lower alcohol contents. However, they aren't as effective as antibacterial rinses in counteracting plaque and gingivitis.
If You’re Concerned About Bad Breath or Gum Disease…Use: An antibacterial formula, which fights bad breath, plaque, and gingivitis. Listerine and other products that contain thymol, eucalyptol, methyl salicylate, and menthol are the only over-the-counter antibacterial mouthwashes to earn the ADA Seal of Acceptance for effectively reducing gum disease and plaque. Antibacterial formulas can reduce bacteria counts in the mouth by an average of 75 percent.
If You’re Cavity Prone, Don’t Have Flouridated Water, or Drink Bottled or Filtered Water…Use: A mouthwash containing fluoride, a mineral naturally found in water and soil, which coats the teeth with a protective film that strengthens tooth enamel, making it more resistant to decay. Fluoride is the only mouthwash ingredient that has been proven to prevent cavities, but it doesn't protect against gum disease. "Unfortunately, antibacterial ingredients are not compatible with fluoride," says John Featherstone, Ph.D., a professor of preventive and restorative dental science at the University of California, San Francisco, "so it's difficult to have an all-in-one mouthwash."
If You Have Gingivitis or Periodontitis…Use: A prescription mouthwash that fights gingivitis-causing germs. Clinical trials have shown that chlorhexidine, the active ingredient in prescription mouthwashes, has much stronger antibacterial properties than the ingredients in over-the-counter brands. These mouthwashes are the only ones approved for treating gum disease by the U.S. Food and Drug Administration. Note: Chlorhexidine can stain teeth a dingy brown. Mouthwashes containing chlorhexidine are prescription-only to ensure that a dentist monitors the staining. Most contain alcohol.