Mouthwash 101: What it does and how to use it 

What is mouthwash?

Mouthwash, also known as mouthrinse, offers a solution to bad breath and can also be an excellent way to supplement your oral health routine. It is designed to be held in the mouth for a period of time, swished around, and then spit out. Mouthwash typically contains antimicrobial and other ingredients designed to inhibit odor-causing sulfur compounds, as well as reduce the bacteria that cause gingivitis and gum disease. Although it can’t replace brushing and flossing for getting rid of the bulk of bacteria on your teeth and gums, it may provide some additional long-term oral health benefit.

Different mouthwashes will have different ingredients depending on their purpose. Some may only tackle bad breath. Others target specific oral health problems with ingredients such as fluoride, which can help prevent cavities, or bacteria-killing agents that reduce plaque and gingivitis. Mouthwash is not a replacement for daily brushing and flossing, but it can help keep your breath fresh for longer and may help improve your oral health in the long run. The best time to use mouthwash is after you have thoroughly brushed and flossed your teeth.

It’s important to note that mouthwash can mask the underlying cause of bad breath (halitosis) which, in some cases, can be an oral or systemic health condition. Talk to your dentist if you’re worried about bad breath – he or she can help you determine the root cause and suggest the best type of mouthwash for your needs.  


Types of mouthwash

The U.S. Food and Drug Administration (FDA) regulates mouthwash as either cosmetic, therapeutic or both. Whereas cosmetic mouthwash is only designed to freshen breath temporarily, therapeutic mouthwash can reduce your risk for oral disease such as gingivitis or cavities.  


  • Cosmetic mouthwash

Cosmetic mouthwash is an over-the-counter product that helps to temporarily control bad breath and leaves behind a pleasant taste but has no chemical or biological application – which means it will not fight plaque, gingivitis, or cavities. Cosmetic mouthwash can, however, help to remove oral debris that might linger after brushing teeth and leave your mouth feeling cleaner than before.

Many dentists are skeptical about the value of cosmetic mouthwash since it will not necessarily improve oral health nor freshen breath for more than about 10-15 minutes.


  • Therapeutic mouthwash

Therapeutic mouthwashes often have multiple benefits. They have active ingredients that, depending on the specific formulation, address or help to prevent various oral diseases and conditions including tooth decay, gum disease, mouth pain, dry mouth, and bad breath. Besides freshening breath, some even offer whitening capabilities.

Many therapeutic mouthwashes are available over the counter, but some require a prescription from your dentist depending on the active ingredient or the strength. Look for mouthwash with fluoride and ingredients such as cetylpyridinium chloride, essential oils, chlorhexidine, and chlorine dioxide, to provide anti-bacterial protection and reduce plaque and gingivitis.

It’s important to note that some mouthwashes contain significant percentages of alcohol (anywhere between 18-26 percent). Although not designed to be swallowed, some may experience sensitivity when rinsing with a mouthwash containing alcohol.  

Which oral health conditions does mouthwash address?

Different formulations of therapeutic mouthwash can treat or address a variety of oral health concerns, including the following:


  • Halitosis (bad breath)

Bad breath is an extremely common oral condition that is most often the result of poor oral hygiene, dry mouth, consumption of certain foods and beverages, or tobacco use. It may also result from an infection within the mouth, certain nose or throat conditions, or even systemic medical conditions.

Mouthwash can remedy bad breath by reducing the amount odor-causing bacteria in the mouth and/or interfering with smelly sulfur compounds and leaving a fresh, clean scent in its place. If you practice good oral hygiene and have a healthy diet, but your bad breath persists, talk to your dentist to rule out any possible underlying conditions. 


  • Gingivitis

Gingivitis is an inflammation of the gums that commonly occurs as a result of plaque buildup on the teeth and gingiva. Plaque contains millions of bacteria. Certain types of mouthwash work to reduce plaque build-up and kill this bacteria, therefore helping to prevent or even reverse gingivitis.


  • Tooth decay

Mouthwash containing fluoride can help prevent tooth decay by strengthening tooth enamel and protecting from acid attacks. The bacteria within plaque produce acids, which eat away at enamel if teeth are not thoroughly cleaned on a regular basis. The bacteria feed on the sugars, starches, and other carbohydrates left on the teeth after eating. Tooth decay starts slowly with the acids eating away at the surface minerals of the tooth enamel. If the process goes on long enough it eventually results in a cavity, or a small hole that forms in your tooth after enough enamel is destroyed. The fluoride in water, toothpaste, rinses and other products helps replace the lost minerals and resist further acid attacks.


  • Topical pain relief

Mouthwashes that offer pain relief most often contain anesthetics, such as lidocaine, that gently numb the mouth to provide relief. These are typically prescribed by your dentist or physician.


  • Whitening

Some mouthwashes are formulated with active ingredients like hydrogen peroxide to reduce staining and whiten teeth. These typically require extended use before any results are noticeable and will not have the same effect as cosmetic whitening procedures performed by your dentist.


  • Dry mouth

Dry mouth, also known as xerostomia, is an oral condition that results from reduced or absent saliva flow; it is a common side effect of certain medications. Mouthwashes that advertise for dry mouth relief help rinse away food particles and freshen breath, and also contain ingredients that lubricate the mouth and ease dry mouth symptoms


  • Alveolar osteitis (dry socket)

Dry socket is a complication of tooth extraction in which the underlying bone and nerves beneath the extraction site are exposed. This results in pain within the socket and along the side of the face. Mouthwash made with chlorhexidine may help prevent dry socket following wisdom tooth (third molar) extractions.1 Chlorhexidene containing rinses must be prescribed by your dentist.


How to use mouthwash

Use mouthwash according to directions on the label or as advised by your dentist. In general, mouthwash can be used anytime but is most effective if you thoroughly brush and floss your teeth first. Simply hold a small amount in your mouth, swish it around, and spit it out. In order to get the maximum benefit from mouthwash, avoid eating, drinking, or smoking for at least 30 minutes after rinsing. Children under six years of age should not use mouthwash as their swallowing reflex is not yet sufficiently developed.

Keep in mind that mouthwash is not meant to replace brushing, and even mouthwashes marketed as anti-plaque or anti-cavity should still be used in addition to a fluoride-containing toothpaste. Studies show that fluoride rinses do, however, provide supplementary benefit in reducing tooth decay.2 If you’re prone to cavities, consider adding mouthwash to your normal routine. Your dentist may prescribe extra-strength fluoride products if you or your child are at especially high risk for decay.  

Mouthwash is not required for good oral hygiene, but it can provide supplementary benefits to your existing brushing and flossing routine. Therapeutic mouthwash, in particular, can help prevent cavities, gingivitis, and plaque buildup – while also reducing the number of odor-causing bacteria in the mouth and freshening breath.

Mouthwash can occasionally mask the signs of a more problematic underlying condition. If you’re experiencing persistent bad breath or other uncomfortable oral symptoms, talk to your dentist. Your dentist can advise you on products and use instructions that can best address the oral problems that you are experiencing.


Thinking about adding mouthwash to your oral health routine? Talk to a dentist.


Additional resources

Looking for more information? Learn more about general oral health and hygiene:



Rodriguez Sanchez F, Rodriguez Andres C, Arteagoitia Calvo I. Does chlorhexidine prevent alveolar osteitis after third molar extractions? Systematic review and meta-analysis. J Oral Maxillofac Surg 2017.

Marinho VC, Chong LY, Worthington HV, Walsh T. Fluoride mouthrinses for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews. Cochrane Systematic Review - Intervention Version published: 29 July ly 2016

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