Enamel Structure

Question 1

Incisors

Answer 1

Cut or shear food, phonetics, functions and esthetics

Question 2

Canines

Answer 2

Seize, pierce, tear and cut food,

Longest roots, key to protection

Question 3

Premolars

Answer 3

Grind and tear

Fine chewing

Question 4

Molars

Answer 4

Large, crushing grinding chewing

Question 5

Enamel

Answer 5

Hardest tissue in body.
Striated because of rods that run all the way to the DEJ.

90-95% inorganic (HA)

Question 6

Dentin

Answer 6

Yellowish, softer than dentin but still harder than bone, striated because of tubules

50% vol inorganic (HA), 25% vol collagen, 25% vol water

75% wt inorganic, 20% wt collagen, 5% wt water

Question 7

Where does enamel come from?

Answer 7

Ameloblasts deposit and then dextinct.

Epithelial origin

Question 8

Hardest enamel is the …

Answer 8

Gnarled enamel

Question 9

Rods run from ____ to surface following a ____ pattern

Answer 9

DEJ, wavy

Question 10

Where does dentin come from?

Answer 10

Mesoderm origin, odontoblasts remain in pulp

Question 11

Dental tubule function

Answer 11

Allow fluid movement and ion transport (remineralization, apposition if peritibular dentin, pain reception)

Question 12

Odontoblastic processes

Answer 12

Cytoplasmic extensions of cell body (tomes fibers)

Question 13

Odontoblasts

Answer 13

Cell bodies line the wall of the pulp chamber

Question 14

Principal organic compound in dentin is…

Answer 14

Collagen

Question 15

Predentin

Answer 15

Unmineralized zone of dentin immediately adjacent to cell bodies of odontoblasts

Question 16

Primary dentin

Answer 16

First dentin formed, up to 3 years after teeth erupt

Question 17

Secondary dentin

Answer 17

Without and obvi stimulus, dentin direction changes and deposition slows

Question 18

What part of the tooth is 100% repairable (as long as pulp is okay)?

Answer 18

Dentin

Question 19

Name the 4 dental pulp functions

Answer 19

Formative or developmental (repairs, makes new dentin)

Nutritive (supplies nutrients and moisture to dentin thru blood vessels)

Sensory or protective (ONLY HAS PAIN RESPONSE, can feel temp)

Defensive it reparative (deposition of reparative dentin, inflammation when hurt)

Question 20

Cementum

Answer 20

Hard, avascular dental tissue covering an atomic roots, formed continually through life. Formed by cementoblasts.

Light yellow, slightly lighter than dentin

Rarely seen clinically

Removed by polishing and abrasion

Highest floride content