Bones support and protect the various organs of the body, produce red and white blood cells, store minerals and also enable mobility.
Other types of tissue found in bones include marrow, endosteum, periosteum, nerves, blood vessels and cartilage.
Enamel is the hardest substance in the human body and contains the highest percentage of minerals,[3] 96%, with water and organic material composing the rest.
In humans, enamel varies in thickness over the surface of the tooth, often thickest at the cusp, up to 2.5 mm, and thinnest at its border with the cementum at the cementoenamel junction.
[9] Enamel does not contain collagen, as found in other hard tissues such as dentin and bone, but it does contain two unique classes of proteins: amelogenins and enamelins.
While the role of these proteins is not fully understood, it is believed that they aid in the development of enamel by serving as a framework for minerals to form on, among other functions.
[14] Cementum is avascular, receiving its nutrition through its own imbedded cells from the surrounding vascular periodontal ligament.
Cementum on the root ends surrounds the apical foramen and may extend slightly onto the inner wall of the pulp canal.