Every day we use it and never wonder about it, so here is a little bit of history for you.
The earliest known reference to toothpaste is in a manuscript from Egypt in the 4th century, but toothpastes or powders did not come into general use until the 19th century.The Greeks and then the Romans, improved the recipes for toothpaste by adding abrasives such as crushed bones and oyster shells(eurkk).
In the 9th century Persian musician and fashion designer Ziryab is known to have invented a type of toothpaste. The exact ingredients of this toothpaste are currently 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 (rags doesn't sound very clean)
An 18th century American and British toothpaste recipe containing burnt bread has been found. Another formula around this time called for dragon's blood a resin, cinnamon, and burnt alum. (eurk again)
By 1900, a paste made of hydrogen peroxide and baking soda was recommended for use with toothbrushes
In 1892, Dr. Washington Sheffield manufactured toothpaste into a collapsible tube.
Fluoride was first added to toothpastes in 1914 and was criticized by the American Dental Association in 1937.
In 1955, Procter & Gamble's Crest launched its first clinically proven fluoride toothpaste.
In June, 2007, the US Food and Drug Administration advised consumers to avoid certain brands of toothpaste manufactured in China, after some were found to contain the poisonous diethylene glycol, also called diglycol or labeled as "DEG" on the tube. The chemical is used in antifreeze as a solvent and is potentially fatal.
Most toothpaste contains trace amounts of chemicals which are toxic when ingested, and it is not intended to be swallowed.
A homemade version of toothpaste can be made by mixing 3 parts baking soda and 1 part salt with: 3 teaspoons of glycerin, 10-20 drops of flavoring and 1 drop of food coloring.
Don't forget to brush and keep on smiling;)