Toothpaste
Toothpaste is a paste or gel dentifrice that is used with a toothbrush to clean and maintain the aesthetics of teeth. Toothpaste is used to promote oral hygiene: it is an abrasive that aids in removing dental plaque and food from the teeth, assists in suppressing halitosis, and delivers active ingredients to help prevent tooth decay and gum disease. Due to variations in composition and fluoride content, not all toothpastes are equally effective in maintaining oral health. The decline of tooth decay during the 20th century has been attributed to the introduction and regular use of fluoride-containing toothpastes worldwide. Large amounts of swallowed toothpaste can be poisonous. Common colors for toothpaste include white and blue.
History
Early toothpastes
Since 5000 BCE, the Egyptians made a tooth powder, which consisted of powdered ashes of ox hooves, pumice, powdered and burnt eggshells and myrrh. The Greeks, and then the Romans, improved the recipes by adding abrasives such as crushed bones and oyster shells.In the 9th century, the Iraqi musician and designer Ziryab invented a type of toothpaste which he popularized throughout Islamic Spain. The exact ingredients of this toothpaste are unknown, but it was reported to have been both "functional and pleasant to taste". It is not known whether these early toothpastes were used alone, were to be rubbed onto the teeth with rags, or were to be used with early toothbrushes, such as neem-tree twigs and miswak. During Japan's Edo period, inventor Hiraga Gennai's Hika rakuyo contained advertisements for Sosekiko, a "toothpaste in a box." Toothpastes or powders came into general use in the 19th century.
Tooth powder
Tooth powders for use with toothbrushes came into general use in the 19th century in Britain. Most were homemade, with chalk, pulverized brick, or salt as ingredients. An 1866 Home Encyclopedia recommended pulverized charcoal, and cautioned that many patented tooth powders that were commercially marketed did more harm than good.Arm & Hammer marketed a baking soda-based toothpowder in the United States until approximately 2000, and Colgate markets toothpowder in India and other countries.
Modern toothpaste
An 18th-century American and British toothpaste recipe called for burned bread. Another formula around this time called for dragon's blood, cinnamon, and burned alum.In 1873 the Colgate company began the mass production of aromatic toothpaste in jars.
By 1900, a paste made of hydrogen peroxide and baking soda was recommended for use with toothbrushes. Pre-mixed toothpastes were first marketed in the 19th century, but did not surpass the popularity of tooth-powder until World War I.
Together with Willoughby D. Miller, Newell Sill Jenkins developed the first toothpaste containing disinfectants, branded as Kolynos. The name is a combination of two Greek words, meaning "beautifier" and "disease preventer". Numerous attempts to produce the toothpaste by pharmacists in Europe proved uneconomic. After returning to the US, he continued experimenting with Harry Ward Foote, professor of chemistry at Sheffield Chemical Laboratory of Yale University. After 17 years of development of Kolynos and clinical trials, Jenkins retired and transferred the production and distribution to his son Leonard A. Jenkins, who brought the first toothpaste tubes on the market on April 13, 1908. Within a few years the company expanded in North America, Latin America, Europe and the Far East. A branch operation opened in London in 1909. In 1937, Kolynos was produced in 22 countries and sold in 88 countries. Kolynos has been sold mainly in South America and in Hungary. Colgate-Palmolive took over the production of American Home Products in 1995 at a cost of one billion US dollars.
Fluoride was first added to toothpastes in the 1890s. Tanagra, containing calcium fluoride as the active ingredient, was sold by Karl F. Toellner Company, of Bremen, Germany, based upon the early work of chemist Albert Deninger. An analogous invention by Roy Cross, of Kansas City, Missouri, was initially criticized by the American Dental Association in 1937. Fluoride toothpastes developed in the 1950s received the ADA's approval. To develop the first ADA-approved fluoride toothpaste, Procter & Gamble started a research program in the early 1940s. In 1950, Procter & Gamble developed a joint research project team headed by Joseph C. Muhler at Indiana University to study new toothpaste with fluoride. In 1955, Procter & Gamble's Crest launched its first clinically proven fluoride-containing toothpaste. On August 1, 1960, the ADA reported that "Crest has been shown to be an effective anticavity dentifrice that can be of significant value when used in a conscientiously applied program of oral hygiene and regular professional care."
Usefulness
Toothpastes are generally useful to maintain dental health. Toothpastes containing fluoride are effective at preventing tooth decay. Toothpastes may also help to control and remove plaque build-up, promoting healthy gums. A 2016 systematic review indicated that using toothpaste when brushing the teeth does not necessarily impact the level of plaque removal. However, the active ingredients in toothpastes are able to prevent dental diseases with regular use.Ingredients
Toothpastes are derived from a variety of components, the three main ones being abrasives, fluoride, and detergent.Abrasives
Abrasives constitute 8-20% of a typical toothpaste. These insoluble particles are designed to help remove plaque from the teeth. The removal of plaque inhibits the accumulation of tartar helping to minimize the risk of gum disease. Representative abrasives include particles of aluminum hydroxide, calcium carbonate, magnesium carbonate, sodium bicarbonate, various calcium hydrogen phosphates, various silicas and zeolites, and hydroxyapatite.After the Microbead-Free Waters Act of 2015, the use of microbeads in toothpaste has been discontinued in the US, however since 2015 the industry has shifted toward instead using FDA-approved "rinse-off" metallized-plastic glitter as their primary abrasive agent. Some brands contain powdered white mica, which acts as a mild abrasive, and also adds a cosmetic glittery shimmer to the paste. The polishing of teeth removes stains from tooth surfaces, but has not been shown to improve dental health over and above the effects of the removal of plaque and Calculus.
Abrasives, like the dental polishing agents used in dentists' offices, also cause a small amount of enamel erosion which is termed "polishing" action. The abrasive effect of toothpaste is indicated by its RDA value. Toothpastes with RDA values above 250 are potentially damaging to the surfaces of teeth. The American National Standards Institute and American Dental Association considers toothpastes with an RDA below 250 to be safe and effective for a lifetime of use.
Fluorides
in various forms is the most popular and effective active ingredient in toothpaste to prevent cavities. Fluoride is present in small amounts in plants, animals, and some natural water sources. The additional fluoride in toothpaste has beneficial effects on the formation of dental enamel and bones. Sodium fluoride is the most common source of fluoride, but stannous fluoride, and sodium monofluorophosphate are also used. At similar fluoride concentrations, toothpastes containing stannous fluoride have been shown to be more effective than toothpastes containing sodium fluoride for reducing the incidence of dental caries and dental erosion, as well as reducing gingivitis. Some stannous fluoride-containing toothpastes also contain ingredients that allow for better stain and calculus removal. A systematic review revealed stabilised stannous fluoride-containing toothpastes had a positive effect on the reduction of plaque, gingivitis and staining, with a significant reduction in calculus and halitosis compared to other toothpastes. Furthermore, numerous clinical trials have shown gluconate chelated stannous fluoride toothpastes possess superior protection against dental erosion and dentine hypersensitivity compared to other fluoride-containing and fluoride-free toothpastes.Much of the toothpaste sold in the United States has 1,000 to 1,100 parts per million fluoride. In European countries, such as the UK or Greece, the fluoride content is often higher; a sodium fluoride content of 0.312% w/w or stannous fluoride content of 0.454% w/w is common. All of these concentrations are likely to prevent tooth decay, according to a 2019 Cochrane review. Concentrations below 1,000 ppm are not likely to be preventive, and the preventive effect increases with concentration. Clinical trials support the use of high fluoride dentifrices, for prevention of root caries in elderly adults by reducing the amount of plaque accumulated, decreasing the number of mutans streptococci and lactobacilli and possibly promoting calcium fluoride deposits to a higher degree than after the use of traditional fluoride containing dentifrices.
Most toothpaste products have a shelf life of about two years, after which the fluoride and antibacterial properties may become less effective. While expired toothpaste is generally safe to use, regulatory bodies like the FDA require expiration dates on fluoride-containing toothpaste to ensure optimal effectiveness.
Surfactants
Many, although not all, toothpastes contain sodium lauryl sulfate or related surfactants. SLS is found in many other personal care products as well, such as shampoo, and is mainly a foaming agent, which enables uniform distribution of toothpaste, improving its cleansing power.Other components
Antibacterial agents
, an antibacterial agent, is a common toothpaste ingredient in the United Kingdom. Triclosan or zinc chloride prevent gingivitis and, according to the American Dental Association, helps reduce tartar and bad breath. A 2006 review of clinical research concluded there was evidence for the effectiveness of 0.30% triclosan in reducing plaque and gingivitis. Another Cochrane review in 2013 has found that triclosan achieved a 22% reduction in plaque, and in gingivitis, a 48% reduction in bleeding gums. However, there was insufficient evidence to show a difference in fighting periodontitis and there was no evidence either of any harmful effects associated with the use of triclosan toothpastes for more than 3 years. The evidence relating to plaque and gingivitis was considered to be of moderate quality while for periodontitis was low quality. Recently, triclosan has been removed as an ingredient from well-known toothpaste formulations. This may be attributed to concerns about adverse effects associated with triclosan exposure. Triclosan use in cosmetics has been positively correlated with triclosan levels in human tissues, plasma and breast milk, and is considered to have potential neurotoxic effects. Long-term studies are needed to substantiate these concerns.Chlorhexidine is another antimicrobial agent used in toothpastes; however, it is more commonly added in mouthwash products. Sodium laureth sulfate, a foaming agent, is a common toothpaste ingredient that also possesses some antimicrobial activities. There are also many commercial products available in the market containing different essential oils, herbal ingredients, and natural or plant extracts. These ingredients are claimed by the manufacturers to fight plaque, bad breath and prevent gum disease. A 2020 systematic metareview found that herbal toothpastes are as effective as non-herbal toothpastes in reducing dental plaque at shorter period of follow-up. However, this evidence comes from low-quality studies.
The stannous ion, commonly added to toothpastes as stannous fluoride or stannous chloride, has been shown to have antibacterial effects in the mouth. Research has shown that stannous fluoride-containing toothpaste inhibits extracellular polysaccharide production in a multispecies biofilm greater than sodium fluoride-containing toothpaste. This is thought to contribute to a reduction in plaque and gingivitis when using stannous fluoride-containing toothpastes when compared to other toothpastes, and has been evidenced through numerous clinical trials. In addition to its antibacterial properties, stabilised stannous fluoride toothpastes have been shown to protect against dental erosion and dentine hypersensitivity, making it a multifunctional component in toothpaste formulations.