Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. combination inorganic/organic material
7. combination inorganic/organic animal material
8. [bone and bone components materials]
9. bone (material)
10. [bone by form as material]
11. [tooth and tooth components as materials]
12. [tooth components as material]

Anotations

Scope note:

Intensely hard calcareous substance covering the dentin, that is, part or all of the crown of the tooth in mammals. Enamel, when mature, consists predominantly of apatite crystals containing calcium and phosphate. Enamel is the hardest tissue of the body; it is not living and contains no nerves. The thickness and density of enamel vary over the surface of the tooth.