Mouthwash | Research & Encyclopedia Articles

Mouthwash

Mouthwash is an oral care product primarily designed to freshen breath and remove food debris. Certain brands are also formulated to aid in the prevention of cavities, decrease buildup of plaque and reduce gum disease.

The first references to mouth freshening products can be found in the records of the early Christian era which indicate that liquid products designed to clean the mouth and freshen breath were in existence at least as early as the first century A.D. Not much is known about these products other than that they were probably simple mixtures of essential oils. During the Arabian Period, between the seventh and twelfth centuries A.D., the science of cosmetics began to flourish. During this time fragrance and flavor oils (such as cassia, clove. nutmeg, musk, myhrr, tamarind, and rose) were discovered. Some of these oils were eventually incorporated into early oral care products.

However, it wasn't until the early nineteenth century that truly functional modern mouthwashes were invented. The first such product was Listerine Antiseptic mouthwash, which was, and still is, marketed by Warner-Lambert. According to company history, Listerine got its start "not in the bathroom but in the operating room." In the late 1880s scientist Joseph Lister discovered that infections could be stopped by killing germs with antiseptic substances such as carbonic acid. One of Lambert's contemporaries, Dr. Joseph Lawrence, was among the many researchers also experimenting with antiseptics. In 1879 Lawrence found a unique combination of essential oils that could be safely used to kill bacteria. Lawrence formulated these oils into a product for use in surgical procedures and named it Listerine in honor of Dr. Lister. Lawrence sold the rights to his invention to in 1884 to Jordan Wheat Lambert who co-founded Warner-Lambert. Lawrence positioned Listerine as the first commercial mouthwash and it went on to become the first product of its kind to earn the American Dental Association's seal of approval. Today a variety of mouthwash products are available in a range of flavors and functions.

Most mouthwash formulations contain water, alcohol, flavor oils, antimicrobial ingredients, foaming agents, colorants, and preservatives. Water is the predominant ingredient and is used as a diluent and solvent for the other ingredients. Water makes up more than 90% of some mouthwash formulations, depending on whether or not alcohol is present. Historically, ethyl alcohol has been added to mouthwashes to give the product a certain mouth-feel, known as bite. The alcohol also helps dissolve the flavor oils and maintains product clarity.

Flavor oils such as peppermint, spearmint, wintergreen are commonly used in mouthwashes. Other popular flavoring agents are based on cinnamon or clove. Listerine uses a combination of natural oils including thymol at 0.064%, eucalyptol at 0.092%, methyl salicylate at 0.060%, and menthol at 0.042% to give it a unique flavor. This blend of ingredients also provides the product with its antimicrobial properties.

In addition to the ingredients used by Listerine, there are a number of other antimicrobial ingredients used in mouthwashes today to kill the germs that contribute to halitosis, or bad breath. These ingredients include cetylpyridinium chloride, domiphen bromide, and benzakonium chloride.

Foaming agents, or surfactants, are added to mouthwashes to help solubolize other ingredients, to aid in cleansing, and to provide a slight amount of foam. Popular foaming agents include anionic surfactants such as sodium lauryl sulfate or nonionic surfactants like Poloxamer.

Finally, a variety of colorants and preservatives are also added to these products. Colorants make the product more aesthetically pleasing while preservatives prevent spoilage from microbial growth. As with all ingredients used in oral care products these must be safe for use in the mouth.

Although mouthwashes were originally little more than flavored water, today's products can deliver efficacious therapeutic agents. For example. the FDA has approved mouthwash formulas for the delivery of fluoride to prevent cavities. In addition, many products are formulated with antiplaque and anticalculus agents. Listerine claims that it "Helps prevent and reduce supragingival plaque accumulation and gingivitis when used in a conscientiously applied program of oral hygiene and regular professional care." Furthermore, it has the American Dental Association Seal of Acceptance for helping control plaque and gingivitis.

In the 1990s mouthwashes have come under increased regulatory scrutiny. In the early 1990s, media attention was focused on a research report which indicated that high levels of alcohol in mouthwash may be linked to certain oral cancers. Despite the attention the matter has received, the data on this subject is not conclusive and the industry maintains that their products are completely safe when used as directed. Still, media pressure prompted many manufactures to eliminate alcohol from existing brands or start new brands which were alcohol free. Other areas of regulatory concern are related to the ability of mouthwashes to reduce plaque and gingivitis. While major manufacturers continue to market products claiming to treat gum disease, the FDA may one day rule that these are drug claims which are not allowable for cosmetic products.