Saturday, March 29, 2008

What TOOTHPASTE all about

Fluoride in various forms is the most popular active ingredient in toothpaste to prevent cavities. 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: NovaMin
Amorphous Calcium Phosphate
Nanit active

These are used both with and without fluoride. 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. Other 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 damage. 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 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 With the exception of toothpaste intended to be used on pets such as dogs and cats, and toothpaste used by astronauts, most toothpaste is not intended to be swallowed, and doing so 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.

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.

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