Toothpaste

Toothpaste is a paste or gel dentifrice used to clean and improve the aesthetic appearance and health of teeth. It is almost always used in conjunction with a toothbrush. Toothpaste use can promote good oral hygiene: it can aid in the removal of dental plaque and food from the teeth, it can aid in the elimination and/or masking of halitosis, and it can deliver active ingredients such as fluoride to prevent tooth and gums (Gingiva) disease. Most people in developed countries consider toothpaste a necessity and use it at least twice a day.

History
It is believed that first traces of oral hygiene were found to be dated around 5000 years ago in Egypt, China and India.

India has a long history of Ayurveda. Neem twigs (a.k.a. daatun) were used for brushing teeth in India. This practice is perhaps one of the earliest and most effective forms of dental care and is still prevalent in villages in India. The usage is simple: you chew one end of the neem twig until it somewhat resembles the bristles of a toothbrush, and then use it to brush your teeth. The tooth brush seems to have its origins in the daatun.

The earliest known reference to a toothpaste is in a manuscript from Egypt in the 4th century A.D., which prescribes a mixture of powdered salt, pepper, mint leaves, and iris flowers. The Romans used toothpaste formulations based on human urine. An 18th century American toothpaste recipe containing burnt bread has been found. Another formula around this time called for dragon's blood (a resin), cinnamon, and burnt alum. 

However, toothpastes or powders did not come into general use until the 19th century in Britain. In the early 1800s, the toothbrush was usually used only with water, but tooth powders soon gained popularity. Most were home made, with chalk, pulverized brick, and salt being common ingredients. An 1866 Home Encyclopedia recommended pulverized charcoal, and cautioned that many patented tooth powders then commercially marketed did more harm than good.

In 1892, Dr. Washington Sheffield of New London, Connecticut manufactured toothpaste into a collapsible tube. Sheffield's toothpaste was called Dr. Sheffield's Creme Dentifrice. He first came up with the idea of toothpaste in a collapsible tube after his son travelled to Paris and saw painters using paint from tubes. In 1896, Colgate Dental Cream was packaged in collapsible tubes imitating Sheffield.

By 1900, a paste made of hydrogen peroxide and baking soda was recommended. Pre-mixed toothpastes were first marketed in the 19th century, but did not surpass the popularity of tooth-powder until World War I. In New York City in 1896, Colgate & Company manufactured toothpaste in the first collapsible tube, similar to that recently introduced for artists' paints.

Fluoride was first added to toothpastes in 1914, and was criticized by the American Dental Association (ADA) in 1937. Fluoride toothpastes developed in the 1950s received the ADA's approval. Countries limit and suggest different amounts acceptable for health. Much of Africa has a slightly higher percent than the U.S.

In June, 2007, the US Food and Drug Administration and similar agencies in Panama, Puerto Rico and Australia advised consumers to avoid, return, or discard certain brands of toothpaste manufactured in China, after batches of Chinese made toothpaste were found to be contaminated with the poisonous chemical Diethylene glycol, also called Diglycol or Diglycol stearate, (or labelled as "DEG" on the tube). The chemical is used in antifreeze as a solvent and is potentially fatal.

Toothpaste is most commonly sold in flexible tubes, though harder containers are available. The hard containers stand straight up, availing more of the toothpaste and saving shelf space.

Active ingredients
Fluoride in various forms is the most popular active ingredient in toothpaste to prevent cavities. Fluoride is the chemical component of toothpaste that makes your teeth white and shiny. Although it occurs in small amounts in plants and animals, and has effects on the formation of dental enamel and bones, it is not considered to be a dietary essential and no deficiency signs are known. Sodium fluoride (NaF) is the most common form ; some brands use sodium monofluorophosphate (Na2PO3F). Nearly all toothpaste sold in the United States has 1000 to 1100 parts per million fluoride ion from one of these active ingredients, in the UK the fluoride content is often higher, a NaF of 0.32% w/w (1450ppm fluoride) is not uncommon. This consistency leads some to conclude that cheap toothpaste is just as good as expensive toothpaste. When the magazine Consumer Reports rated toothpastes in 1998, 30 of the 38 were judged excellent. Application of fluoride also prevents moisture build-up in some surfaces.

Fluoride has been used in toothpaste since the 1950s: history of fluoride use.

A range of other ingredients are less commonly used.

Hydroxyapatite nanocrystals are used for remineralization, as in the Apagard and BlanX brands.

A more recent family of active ingredients use calcium phosphate for remineralization. Calcium phosphate technologies include: These are used both with and without fluoride.
 * NovaMin
 * Recaldent
 * SensiStat
 * Amorphous Calcium Phosphate
 * Nanit active

Calprox is used in Supersmile. Cuprident uses mono-copper citrate (MCC).

Some toothpastes include ingredients to reduce sensitivity; they can either treat an underlying cause (if sensitivity is caused by demineralization, remineralization repairs this), or suppressing the symptoms by desensitizing the nerves.

Inactive ingredients
Many, though not all, toothpastes contain sodium lauryl sulfate (SLS) or another of the sulfate family. SLS is found in other personal care products as well, such as shampoo, and is largely a foaming agent. SLS may cause a greater frequency of mouth ulcers in some people as it can dry out the protective layer of oral tissues causing the underlying tissues to become damaged. Some brands include powdered white mica. This acts as a mild abrasive to aid polishing of the tooth surface, and also adds a cosmetically-pleasing glittery shimmer to the paste. Many may include frustules of dead diatoms, as a mild abrasive.

Ingredients such as baking soda, enzymes, vitamins, herbs, calcium, calcium sodium phosphosilicate, mouthwash, and/or hydrogen peroxide are often combined into base mixes and marketed as being beneficial. Some manufacturers add antibacterial agents, for example triclosan or zinc chloride, to prevent gingivitis. Triclosan is a very common ingredient in the UK.

Toothpaste comes in a variety of flavors, most often being some variation on mint (spearmint, peppermint, regular mint, etc). Other more exotic flavors include: anise, apricot, bubblegum (marketed mostly to children), cinnamon, fennel, neem, ginger, vanilla, lemon, orange, pine. Flavors which have been introduced but discontinued due to poor reception include peanut butter, iced tea, and even whisky. Some brands of toothpaste are unflavored, but many are both flavored and sweetened. Because sugar can cause tooth decay, artificial sweeteners are generally employed for this purpose. The inclusion of sweet-tasting but highly toxic diethylene glycol in Chinese-made toothpaste led to a multi-nation and multi-brand toothpaste recall in 2007.

Many toothpastes contain colorings for better visual acceptance.

Toxicity
Toothpaste is not intended to be swallowed and may cause nausea or diarrhea; fluoride toothpaste is toxic when swallowed. Extended consumption while the teeth are forming can result in fluorosis. This is why young children should not use fluoride toothpaste except under close supervision. There are several non-fluoride toothpaste options available in the market for those with no tolerance to fluoride.

Striped toothpaste
Striping of toothpaste is solely for the purpose of providing an alternative appearance; it provides no functional benefit to the consumer.

Striped toothpaste can be produced by including two different colored toothpastes in an unusual type of packaging. The collapsible tube has two tanks, one filled with each color paste (see figure). Squeezing the tube pushes the two pastes out the opening. The tube nozzle layers the pastes to produce a striped pattern. To keep the cost of packaging to a minimum, it is now common for tubes to be filled with striped paste (e.g. Aquafresh). As the tube is squeezed, the stripes flow parallel to each other and do not mix. The patterned paste that gets dipensed is simply a narrower version of what is in the tube. Filling is done using a multi-nozzle filling head that dispenses a different colored stripe in each direction. To keep the stripes parallel to the axis of the tube, the head starts at the bottom and retracts as it fills, staying just above the level of the paste. Tubes with two compartments are generally reserved for toothpastes containing two formulas intended to react together and therefore kept isolated until dispensed (e.g. Colgate Simply White).