Mouthwash, also known as oral rinse, is a liquid product used to supplement the daily routine of brushing and flossing. Rinses are broadly categorized into two main types: cosmetic and therapeutic. Cosmetic mouthwashes primarily offer a temporary, pleasing taste and mask bad odors without having a biological effect on oral health. Therapeutic rinses contain active ingredients designed to deliver a chemical or biological benefit, such as reducing plaque, preventing decay, or managing gum inflammation.
Controlling Odor and Freshening Breath
A common reason people reach for a mouthwash is to combat halitosis, or bad breath. Cosmetic rinses use flavorants and fragrances to temporarily cover up the odor. Therapeutic mouthwashes address the underlying cause of the odor, which is often the metabolic waste produced by bacteria in the mouth.
These bacteria, especially those found on the back of the tongue, break down food debris and proteins to produce foul-smelling volatile sulfur compounds (VSCs). Ingredients like zinc salts, chlorhexidine, and cetylpyridinium chloride (CPC) can chemically neutralize VSCs or kill the odor-producing bacteria. Essential oils, such as eucalyptol, menthol, and thymol, also inhibit VSC-producing bacteria. Therapeutic rinses containing these agents offer more prolonged control over oral malodor.
Reducing Plaque and Treating Gingivitis
For individuals seeking to improve gum health, therapeutic mouthwashes contain antimicrobial agents that target the bacterial biofilms forming plaque. Plaque accumulation along the gumline is the primary cause of gingivitis, the initial stage of gum disease characterized by inflammation, redness, and occasional bleeding. Antiseptic ingredients work by disrupting the cell walls of oral microbes, either killing them or inhibiting their growth.
Over-the-counter (OTC) antiseptic rinses often utilize essential oils or cetylpyridinium chloride (CPC) to reduce plaque and manage gingivitis. CPC is a broad-spectrum antimicrobial that binds to the oral tissues, preventing bacteria from colonizing. For moderate to severe cases of gingivitis, a dentist may prescribe a stronger antimicrobial mouthwash containing chlorhexidine. Chlorhexidine is highly effective at reducing bacteria and inflammation, though it is typically reserved for short-term use due to potential side effects like tooth and tongue staining.
Supporting Enamel Health
A primary function of certain mouthwashes is to strengthen tooth enamel and prevent dental caries, or cavities, through the action of fluoride. Enamel, the hard outer layer of the tooth, constantly undergoes demineralization and remineralization. Acids produced by plaque bacteria cause demineralization, weakening the enamel structure.
Fluoride works by promoting remineralization, facilitating the deposit of calcium and phosphate ions back into the enamel. When fluoride is present, the remineralized enamel forms a crystal structure called fluorapatite, which is significantly more resistant to acid attacks. Fluoride mouth rinses deliver this mineral to all tooth surfaces, including hard-to-reach areas, providing a supplementary benefit beyond what is achieved with fluoride toothpaste alone. This topical application helps repair microscopic damage and fortifies the teeth against future decay.
Guidelines for Safe and Effective Use
To maximize the benefits of any mouthwash, follow specific application guidelines. The typical recommended dosage is between 3 to 5 teaspoons (about 20 milliliters), which should be swished vigorously for 30 seconds to one minute, depending on the product’s instructions. After swishing, the rinse should be spit out, as the ingredients are not meant to be ingested.
For therapeutic rinses, particularly those containing fluoride, avoid eating, drinking, or rinsing with water for at least 30 minutes after use. Rinsing with water immediately afterward dilutes the active ingredients, washing away the protective film and reducing effectiveness. Mouthwash should be used after brushing and flossing to ensure the active agents can reach the cleaned tooth surfaces. Alcohol is included in some formulations to dissolve active ingredients, but alcohol-free versions are widely available for those who experience sensitivity or dry mouth.