EX1; Enamel Tissue Flashcards Preview

May14 Oral Histology > EX1; Enamel Tissue > Flashcards

Flashcards in EX1; Enamel Tissue Deck (47)
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1

True or False
Enamel is the second hardest of the 4 mineralized tissues in the body

False; it IS THE hardest of the tissues

2

What is different about the ectodermal derived tissue that forms enamel

it is epithelium;
the other tissues of the tooth are connective tissue

3

What is different about the mineralization stages of enamel

it does not have an unmineralized or pre enamel formation stage
it has an immature (partially mineralized) and mature (fully mineralized)

4

Enamel is considered what because the ameloblast completes its enamel formative cycle once the correct thickness is achieved

finite

5

True or False
Enamel is the second mineralized tissue to appear

True; dentin is the first

6

Enamel is subject to what due to genetic and external factors (age changes, habits, smoking, etc.)

malformations

7

Enamel does not contain what compared to other tissues

enclosed cells; acellular, aneural, avascular, and alymphatic

8

*What is the definition of enamel

a composite biological mineral with apatite crystals oriented in a complex three dimensional pattern

9

What is apatite on the Mohs mineral hardness scale

5

10

What does enamel need to maintain its integrity

a wet environment

11

What forces is enamel subject to

attrition (normal)
abrasion
erosion

12

These are pathways for the diffusion of small molecules such as water and bactera

micropores (microporosity)

13

What is the inorganic, organic, and water weight of enamel

96% inorganic
1% organic
3% water

14

What is the principal mineral component of enamel

calcium hydroxyapatite (fluro exchanged when there is fluoride present)

15

What is the main protein (90%) composing the organic component of enamel

amelogenin

16

Enamel is the only tooth tissue that does not contain what

collagen fibers

17

How is the water distributed throughout enamel

via micropores between the crystals and proteins

18

What are the CEJ relationships

cementum overlaping enamel (most commong)
cementum meeting enamel
cementum does not touch enamel (least common)

19

What are the different configurations of the DEJ

scalloped
smooth

20

This DEJ configuration is better adapted for occlusal forces

scalloped; in the coronal area

21

This DEJ configuration is better for non-load bearing areas

smooth; in the cervical areas

22

These are growth lines found on enamel

lines of Retzius

23

These are ridges (wave-like) on the exposed surfaces of enamel centered between the lines of Retzius (grooves)

perikymata

24

This is the structural unit of enamel

enamel rods

25

Where are the HA crystals most dense in the enamel rod

in the center or core of the rod running parallel

26

What forms the enamel rods

ameloblast (one ameloblast = one rod)

27

This is the outer surface of the rod

enamel sheath

28

How are the HA crystals of the enamel sheath arranged

they are less dense (more organic %) and run in different directions

29

What substance is in the highest percentage of the organic material of the enamel sheath

amelin

30

This is located between the sheath of rods

interrod substance