Biological Factors (Melfi)

Question 0

T or F: dental-pulp all junction is always changing

Answer 0

True

Question 1

What are the two most bio- compatible tissues of a tooth?

Answer 1

Dentin and pulp

Question 2

What embryological germ layer do oral tissues arise?

Answer 2

Ectoderm

Question 3

What histological tissue type is dentin and pulp?

Answer 3

Connective tissue

Question 4

What type of tissue is enamel?

Answer 4

Hard derived epithelial tissue

Question 5

What are the four classic pulp tissue functions?

Answer 5

1. Formative: produces dentin
2. Nutritive: nourishes a vascular dentin
3. Protective: carries nerves that give dentin sensitivity
4. Reparative: produces new dentin due to external stimuli

Question 6

What tissue helps maintain dentin as a vital tissue?

Answer 6

Pulp

Question 7

What is the chemical composition of dentin?

Answer 7

70% inorganic hydroxyapatite
20% organic mostly collagen type 1
10% water

Question 8

What percent of enamel is inorganic?

Answer 8

96%

Question 9

What is contained in the dentinal tubules?

Answer 9

Odonoblast processes and tissue fluid

Question 10

Where is the nucleus of the odonoblast located?

Answer 10

In pulp

Question 11

What cell secretes dentin?

Answer 11

Odonoblast

Question 12

What is the hardest part of dentin?

Answer 12

Peritubular dentin: wall of tubule

Question 13

What is the softest dentin?

Answer 13

Predentin

Question 14

What makes up the composition of pulp?

Answer 14

• different cell types
• extracellular substance (organic): type 1 collagen (90%)
• tissue fluid
• blood vessels, lymph vessels, nerve fibers

Question 15

What is the origin and function of tissue fluid?

Answer 15

Origin: blood supply
Function: conveys nutrients and metabolites to pulp and dentin

Question 16

What are the two classes of extracellular substance in pulp?

Answer 16

1. Fibers: type 1 collagen (90%)

2. Non-fibrous (ground substance): glycosaminoglycans, glycoprotein

Question 17

What cell type belongs to both pulp and dentin?

Answer 17

Odontoblasts

Question 18

What are the four cell types in pulp?

Answer 18

1. Odonoblasts ( most prominent cell of dental pulp)
2. Fibroblasts (most numerous cell in pulp tissue)
3. Defense cells: macrophages and dendritic cells
4. Undifferentiated mesenchymalmcells (stem cells)

Question 19

What cell secretes and loses the extracellular substances?

Answer 19

Fibroblasts

Question 20

What is the first tissue to show up in a developing tooth?

Answer 20

Dentin

Question 21

What is the predentin layer?

Answer 21

Unmineralized dentin secreted by Odonoblasts

Question 22

The dentinopulpal junction forms what?

Answer 22

Tight junction

Question 23

What is the current theory of tooth pain?

Answer 23

Hydrodynamic theory- when cut, the tissue fluid is disturbed and current travels to nerve for pain

Question 24

T or f: there are nerves in dentin?

Answer 24

False

Question 25

What are dead tracts of dentin?

Answer 25

Empty dentinal tubules filled with air that does not transmit pain

Question 26

What is reparative dentin?

Answer 26

Reactive. It's produced by Odonoblasts directly after stimulus. It is formed under the stimulus at the pupal surface of dentin

Question 27

What is sclerotic dentin?

Answer 27

Transparent dentin. Deposition of mineral salts within dentinal tubules-> tubules obliterated.

Question 28

What is one major reason reparative dentin is made?

Answer 28

To protect the pulp

Question 29

From external to internal, order the following: Dead tract dentin, sclerotic dentin and reparative dentin.

Answer 29

External: sclerotic ( closest to stimulus) Middle: dead tract Internal: reparative

Question 30

What are pulp stones?

Answer 30

Ectopic mineralizations with in pulp tissue

Question 31

T or f: a young tooth has a bigger pulp chamber than a old tooth?

Answer 31

True