Figure 5.
Dental hard tissues: colored scanning electron micrograph (SEM) of the boundary between tooth enamel (top) and dentin (bottom). Enamel is the outer covering of the crown (visible part) of the tooth. It is the hardest substance in the human body, comprising rows of hydroxyapatite (calcium and phosphorus salts) embedded in a protein matrix. Dentin makes up the majority of the tooth. It comprises mineralized connective tissue. Magnification: 500× when printed 10 cm wide (permitted by http://www.sciencephoto.com).
SEM: scanning electron micrograph.
