Toothpaste
Toothpaste is a paste used, almost always in conjunction with a toothbrush, to clean teeth.
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. Many early toothpaste formulations were based on urine. However, toothpastes or powders did not come into general use until the 19th century.
In the early 19th century 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 Cyclopedia recommended pulverized charcoal, and cautioned that many patented tooth powders then commercially marketed did more harm than good.
By 1900, baking soda made into a paste by adding a small amount of hydrogen peroxide solution was recommended. Pre-mixed toothpastes were first marketed in the 19th century, but did not surpass the popularity of tooth-powder until about the time of the World War I.
Fluoride started to be added to toothpastes in the 1950s. Different countries have slightly different suggestions and limits in regards to the amount of the chemical to be added into the product. For example, much of Africa has a slightly higher percent than the US.
Like many shampoos, healthier ingredients (such as baking soda, psuedo-mouthwash etc) are often combined into base mixes of varying qualities and marketed as being benefical.
Toothpaste is most commonly sold in flexible tubes, although one may also purchase it in harder containers. Packages designed to stand straight up, so as to allow more of the toothpaste to be used, are a relatively recent innovation.
Toothpaste comes in a variety of flavors, most often being some variation on mint (spearmint, peppermint, regular mint etc). Other more exotic flavors include : orange, cinammon, bubblegum (marketed mostly to children), even unflavored.
Toothpaste is intended to be spat out. Some types of toothpaste may even be toxic if swallowed in sufficient quantity. This is why children of a young age should not use it, or use it only under close supervision.
Popular brands
There are others as well, including Tom's of Maine, which is a more-natural-ingredient-based blend.