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Oral Histology > Enamel > Flashcards

Flashcards in Enamel Deck (91)
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0

% of mineralization of enamel?

96-98%

1

Color of enamel?

White to grayish white

Translucent

2

True or false. After eruption, enamel increases density?

True

3

True or false. After eruption, enamel becomes less permeable?

True

4

Substances that enamel allow to flow through? (2)

  • Water
  • Alcohol

5

Texture of enamel?

Smooth and glossy

6

Specific gravity of enamel?

2.8

7

Chemical formula of hydroxyapatite?

CaPO4

Fluorine and chlorine can be substituted for OH groups

8

Organic content of enamel?

Enamel proteins (2-4%)

9

Enamel proteins are collagenous or non-collagenous?

Non-collagenous

10

Loss of function of amelogenin would cause?

Thin enamel without enamel rods

11

It inhibits lateral growth of hydroxyapatite?

%?

Amelogenins; 90%

12

Hydrophobic proteins rich in proline, histidine and glutamine?

Amelogenin

13

Enamel protein found mostly in newly formed enamel?

Ameloblastin

14

Loss of ameloblastin would cause?

  • Terminal branching
  • Detachment of ameloblast from dentin
  • Amelogenesis aborts

15

Largest but least abundant enamel protein?

Enamelin

16

Fundamental organizational unit of enamel?

Enamel rods

17

Shape of immature enamel rods?

Hexagonal

19

General direction of enamel rods?

Perpendicular to DEJ

19

Direction of enamel rods under pits and fissure?

Tentlike

20

Direction of enamel rods in proximal?

Horizontal

21

Direction of enamel rods in cervical of deciduous teeth?

Coronally oblique

22

Direction of enamel rods cervical of permanent teeth?

Apically oblique

23

Its crystals are oriented in a different direction from enamel rod?

Interrod enamel

24

Accounts for the fish scale appearance?

Enamel rod sheath

25

True or false. Enamel rod sheath contains more inorganic material than enamel rod and interrod enamel?

False.

Enamel rod sheath is more organic

26

True or false. Enamel rod sheath are more acid resistant.

True

27

True or false. Enamel rod sheath covers the entire rod.

False

28

Incremental lines of enamel?

Striae of Retzius

29

Striae of Retzius run from the DEJ in an ________ direction to the occlusal surface.

Oblique