There is More to Your Mouthwash Than a Minty Taste

People gargle mouthwash thinking it will get rid of bad breath, but that is the minty liquid’s least effective function.

Dentists say mouthwash and other rinses can be beneficial to overall oral health and an important part of daily oral hygiene routines but aren't essential.

Mouthwashes can be divided into two main categories: cosmetic and therapeutic. Cosmetic rinses reduce and help control bad breath and leave a pleasant taste in the mouth, said Peter Arsenault, division head of operative dentistry at Tufts University School of Dental Medicine.

But, “they don’t really deal with the actual cause of bad breath—they don’t kill the bacteria and they don’t chemically inactivate the compounds that cause bad breath,” said Dr. Arsenault.

Therapeutic rinses have more targeted functions and come both over-the-counter and by prescription. They can help reduce tooth plaque or gingivitis, inflammation of the gum which can lead to gum disease. They can also help neutralize the acidity of the mouth to lessen the decay process. They may hydrate individuals who suffer from dry mouth, and help soothe canker sores. Fluoride and xylitol rinses aid in cavity prevention.

Sales of mouthwash have been robust, increasing each year over the past five years, according to data from Euromonitor International, a market research firm. In 2008 sales of mouthwashes and rinses totaled $1.4 billion and were projected to go up to $1.5 billion in 2014.

The American Dental Association, a professional association of dentists, tests products and has a council on scientific affairs which evaluates products to determine if they are safe and effective. Those that pass the tests receive a seal, which can be found on the product. Currently, 128 mouthwashes have the seal.

The ADA has found just two products that satisfy claims they eliminate bad breath and neither are mouthwashes. They are toothpastes, said Clifford Whall, director of the seal of acceptance program at the Chicago-based ADA.

Some therapeutic rinses work by neutralizing the pH of the mouth, said Dr. Arsenault. When the bacteria in our mouth consume carbohydrates and sugars, their metabolic waste is acid. The acid draws out the minerals, resulting in an acidic mouth that leads to tooth decay.

An important ingredient to look for in such rinses is xylitol, a naturally occurring sugar alcohol which certain bacteria are unable to metabolize. “It kind of results in the bacteria in your mouth choking,” said Dr. Arsenault. Xylitol stimulates salivary function due to its sweetness and taste and helps restore the mouth to a neutral level of acidity.

But some dentists, such as Judith Jones, a professor of general dentistry at Boston University, recommend looking for alcohol-free mouthwashes because they can dry out the mouth. A dry mouth can end up encouraging bacterial activity, resulting in worse breath.

Alcohol is used as a preservative—to increase the shelf life of mouthwash—and as a carrier for flavor. The alcohol itself isn't the antispectic. Rather, it dissolves essential oils (like menthol and eucalyptol) or active ingredients, which together have an antiseptic effect.

The therapeutic mouthwashes with the ADA seal currently have alcohol in them, said Dr. Whall.

“Your saliva is more than adequate to keep the mouth moist,” said Dr. Whall. “It might be an issue for people who have dry mouth,” as alcohol could irritate their mouth.

Studies have found an association between the alcohol in mouth rinses and oral cancer.

But some experts say such evidence is weak. “The association between mouthwash and oral cancers is not strong,” said Mumtaz Khan, a head and neck cancer surgeon at Cleveland Clinic. “I personally do not tell my patients not to use mouthwash.”

Dr. Jones, of Boston University, said she recommends only fluoride rinses and prescription mouthwashes, which are used in specific situations, such as after gum surgery or an infection. Fluoride rinses typically don't contain alcohol and can usually be used by children age 6 and above. Before that age manufacturers and dentists don’t recommend them because children may swallow the fluid.

“Daily fluoride rinses work really well,” said Dr. Jones. “It’s as good as getting two fluoride treatments.”

But fluoride rinses are only important for individuals who are prone to cavities, she said. “If you’ve had one or more new cavities in the last year then you should have some kind of additional fluoride,” she said.

Dentists warn that individuals who find that they need to use mouthwash excessively for bad breath may have an underlying problem that needs to be addressed.

“There are a lot of things that can cause bad breath that aren't going to be remedied by mouthwash—cosmetic or therapeutic,” said Ada Cooper,a dentist in Manhattan, New York, and an ADA Consumer Advisor spokesperson. “Deep cavities, untreated periodontal or gum disease, infections of the gum and bone, can all cause breath to be incredibly strong.”

Using mouthwash before or after you brush and floss doesn’t make a difference, said Dr. Cooper.

In some cases, a dentist may give more specific instructions. If a mouthwash is prescribed after oral surgery, a dentist may instruct you to focus it on the area where the surgery occurred. If you have a tendency to accumulate bacteria and plaque in your lower front teeth, the dentist may suggest that you focus on rinsing in that area, said Dr. Cooper.

Mouthwash isn't a substitution for flossing, said Dr. Cooper. “I often recommend it to my patients as a helpful adjunct to brushing and flossing. It simply can add additional protection against cavities and gum disease.”