Mouthwash is a liquid solution that is swished around inside the mouth to cover the teeth, gums and tongue, and then is spit out. Some types of mouthwashes help to temporarily mask bad breath (halitosis) as well as rinse the area of debris and bacteria. Others are intended to coat the teeth with fluoride to strengthen them and help prevent decay. Mouthwash may be available in over-the-counter or prescription forms.

Mouthwash is intended to be a supplement to (not a replacement for) good oral hygiene practices, such as daily brushing and flossing. It is typically used after brushing and flossing and is not diluted.

When mouthwash is used, patients should follow the directions provided by their dentist or on the product packaging. Mouthwash should be swished around vigorously so that it rinses the front and sides of the mouth equally. In some cases, patients may be directed to gargle. This involves raising the chin and saying “ahhh” while holding liquid in the mouth and keeping the throat closed. This type of rinsing is especially effective at reaching the back of the tongue, where bacteria may accumulate.

In most cases, patients are urged to swish for about 30 seconds before spitting out the mouthwash. Typically, patients should avoid eating, drinking or rinsing the mouth for up to several hours after using mouthwash, depending on the type used.

Active ingredients in mouthwash can vary, and each provides a different function. Some common ingredient types include:

• Antimicrobials (e.g., cetylpyridinium chloride, chlorhexidine, sanguinarine, phenolic compounds). These ingredients help reduce the amount of bacteria in the mouth.
  
  
• Deodorizing and oxidizing agents (e.g., sodium bicarbonate and chlorine dioxide, respectively). These help to mask and neutralize bad odors.
  
  
• Oxygenating agents (e.g., hydrogen peroxide). Helps to kill anaerobic germs (those that live without oxygen) by adding oxygen to the area.
  
  
• Fluoride. Strengthens teeth and prevents tooth decay.
  
  
• Astringents (e.g., citric acid, zinc chloride). These provide a pleasant taste and shrink oral tissues.
  
  
• Pain-relieving agents (e.g., anodynes). These provide pain relief.
  
  
• Buffering agents. These ingredients may relieve soft-tissue pain, reduce acidity and dissolve build-up of film on the lining of the mouth.
  
  
• Antitartar (e.g., zinc citrate) agents. Reduce tartar build-up in the mouth.

Inactive ingredients in mouthwashes include those that dilute and sustain the active ingredients (e.g., water, alcohol), as well as those that add flavor or color. Most commercial mouthwashes contain a significant amount of alcohol as an inactive ingredient.

When selecting over-the-counter dental care products such as mouthwash, patients are advised to look for the American Dental Association Seal of Acceptance. This indicates a product is safe and effective.