DID YOU KNOW: Enamel is the hardest substance in the body.
Tooth enamel is one of the four major tissues that make up the tooth in humans and many other animals. It is a protective layer which represents the visible part of the tooth, covering the crown. The other four major tissues are dentin, cementum, and dental pulp.
Enamel is known to be the most solid and most mineralized substance in the body. It is made of 96% minerals and 4% of water and organic materials, where the primary mineral is called hydroxyapatite.
The hardness of enamel is an important property as the main role is to protect the softer underlying dentin of the tooth. Enamel also serves as the surface for chewing grinding and crushing of food and this is another reason for its hardness. Since this protective tooth layer also keeps teeth from becoming sensitive, it must withstand heat and cold, as well as biting into hard surfaces.
Enamel is formed on the tooth while the tooth is developing within the gum, before it erupts into the mouth. Once fully formed, it does not contain blood vessels or nerves. For that reason, enamel is one of the only body tissues that DOES NOT regenerate itself when it is damaged, meaning that technically it should last a lifetime.
Enamel can break down over time due to build-up of bacteria known as plaque or it could be eroded after prolonged exposure of acids and low pH foods. In addition to breakdown in enamel that can happen over time, enamel can be subject to chipping and cracking from a traumatic injury or biting on a hard substance. Remineralisation of teeth can repair damage to the tooth to a certain degree but damage beyond that cannot be repaired by the body. For this reason, it is indispensable to focus on prevention by keeping the teeth healthy and cavity free.