Mouthwashes may be classified as cosmetic, therapeutic or a combination of the two.

Cosmetic mouthwashes (sometimes called antiseptics) are available over the counter. They are typically made up of phenol-related essential oil compounds that contain active ingredients such as thymol, methyl salicylate, menthol and eucalyptol. Many contain a significant amount of alcohol, although some are available without alcohol.

Most cosmetic mouthwashes perform the following functions:

• Temporarily mask bad breath (halitosis)
• Rinse away oral debris
• Temporarily reduce bacterial levels in the mouth
• Provide a pleasant, refreshing taste

Manufacturers often claim these types of mouthwashes are an effective way to promote oral health, but dental experts disagree about their effectiveness in reducing dental plaque. An antiseptic mouthwash may kill germs, but does so temporarily because bacteria can develop quickly in the mouth. In fact, some experts believe that rinsing the mouth with water may be as effective as using a cosmetic mouthwash.

Some recent studies have contended that an oral rinse can be as effective as flossing in reducing plaque. However, the American Dental Association (ADA) states that these claims have not been adequately substantiated. Flossing continues to be an important method of removing debris that becomes stuck between teeth and may be difficult to rinse away. Even if these mouthwashes do reduce plaque, they should be used in addition to, not in place of, proper brushing and flossing.

In addition, cosmetic mouthwashes mask rather than eliminate bad breath. The odor-masking properties of these mouthwashes last for up to three hours. Patients with persistent bad breath are advised to contact their dentist or physician. Chronic halitosis may indicate a dental condition (e.g., oral infections, dry mouth) or medical condition (e.g., diabetes, respiratory tract infection) that needs treatment.

Therapeutic mouthwashes offer most of the benefits of cosmetic rinses, but contain an added active ingredient that helps prevent or treat certain oral health conditions. These types of rinses are regulated by the U.S. Food and Drug Administration (FDA) and voluntarily approved by the ADA. They usually fall into one of two categories:

• Antiplaque/antigingivitis rinse. This type of therapeutic mouthwash has been shown to control bacterial plaque and to reduce and inhibit gingivitis. Many of these rinses contain chlorhexidine gluconate and are available by prescription only. They may have an unpleasant taste or may leave a bitter aftertaste in the mouth. These solutions usually include alcohol, although they may be available without alcohol. They are recommended for short-term use only (e.g., six months or less).
  
  
• Anticavity fluoride rinse. These rinses include fluoride, which helps strengthen teeth and prevent decay. They are available over-the-counter and by prescription (for a higher-concentration level of fluoride). People at high risk of tooth decay, as well as patients with orthodontic appliances, may be advised to regularly use these types of rinses in addition to their daily oral hygiene regimen.

In lieu of commercial mouthwashes, a simple saltwater mouth rinse can be made at home. This involves mixing 1/2 teaspoon salt in 8 ounces of water. It is less irritating than alcohol-based rinses and can be used to cleanse oral tissue.