Enamel

Question 1

What is enamel?

Answer 1

Mineralised structure that makes up the outer layer of the tooth crown.

Question 2

Enamel is translucent, how does this impact the colour of a tooth?

Answer 2

Light passes through enamel and shows the colour of tooth as the colour of the dentine.

Question 3

Where is enamel thickest?

Answer 3

Incisal edge and surface enamel.
Thinnest at the ACJ and cervical region.

Hardness also follows the same pattern.

Question 4

What cells produce enamel?

Answer 4

Ameloblasts

Question 5

What cells produce dentine?

Answer 5

Odontoblasts

Question 6

What is the main unit of enamel?

Answer 6

Enamel rods.

Question 7

What are enamel rods?

Answer 7

Polarised cells which are crystallised- hydroxyapatite crystallites are deposited at right angles to ameloblast membrane.
Chrystallites are inside the rod but perpendicular to ADJ and parallel to the rod itself.

They run from ADJ to surface

Question 8

What makes up the bulk of enamel content?

Answer 8

90% hydroxyapatite
5-10% water
1-2% organic matrix- amelogenins, enamelings, peptides, amino acids.

Question 9

What is hydroxyapatite made of?

Answer 9

Calcium, phosphate and hydroxyl.