Dentin Pulp Complex TEST #3 2/23/17

Question 1

What is the main cellular component of the tooth?

Answer 1

-Pulp

Question 2

What is the main mineralized structural component of the tooth?

Answer 2

-Dentin

Question 3

What is the main mineralized protective component of the tooth?

Answer 3

-Enamel

Question 4

What is the percentages of material in dentin?

Answer 4

• 70% inorganic (hydroxyapatite)
• 20% Organic
• 10% Water

Question 5

Are the dentin tubules fluid filled?

Answer 5

-Yes

Question 6

What form does collagen have?

Answer 6

-Triple helix

Question 7

Can fluoride, magnesium, and zinc be incorporated into the inorganic material of dentin?

Answer 7

-Yes

Question 8

In Dentin, what are the shapes of the Hydroxyapatite crystals?

Answer 8

-Flattened into rectangular plates

Question 9

T/F Bone is harder than dentin

Answer 9

False

-Dentin is slightly harder than bone

Question 10

In the 20% of the organic material found in dentin what percentage of that is collagen?

Answer 10

-90%

Question 11

In the 20% of the organic material found in dentin what percentage of that is non-collagenous proteins?

Answer 11

-10%

Question 12

In the organic material in dentin what is the main type of collagen found?

Answer 12

-Type I

Question 13

What are the three types of collagen found in the organic material of dentin?

Answer 13

• Type I
• Type III
• Type V

Question 14

What is the purpose of the fibrillar collagen scaffold?

Answer 14

-It is where HA crystals are laid down

Question 15

Dentin Sialophosphoprotein (DSPP) are cleaved into what three dentin specific non-collagenous proteins of dentin?

Answer 15

• DSP
• DGP
• DPP

Question 16

What enzyme cleaves DSPP?

Answer 16

-BMP-1

Question 17

What cleaved product of DSPP is a proteoglycan?

Answer 17

-DSP

Question 18

What cleaved product of DSPP is a glycoprotein?

Answer 18

-DGP

Question 19

What is the purpose of DGP?

Answer 19

-Helps in mineralization

Question 20

What is the purpose of DSP?

Answer 20

-Prevent mineralization

Question 21

What cleaved product of DSPP binds lots of Ca2+ to initiate HA formation?

Answer 21

-DPP

Question 22

What cleaved product of DSPP is attached to collagen?

Answer 22

-DPP

Question 23

What can defects in DSPP cause?

Answer 23

-Dentinogenesis imperfect Type II and III

Question 24

What is type I dentinogenesis imperfecta caused by?

Answer 24

-Defect in Collagen I

Question 25

What happens with the pulp chamber in type I dentinogenesis imperfecta?

Answer 25

-Fills with abnormal dentin

Question 26

What is type II dentinogenesis imperfecta caused by?

Answer 26

-DSPP defect

Question 27

What happens with the pulp chamber in type II dentinogenesis imperfecta?

Answer 27

-Fills with abnormal dentin

Question 28

What type of pulp chamber do you see in type III dentinogenesis imperfecta?

Answer 28

-Enlarged pulp chambers

Question 29

What type of dentinogenesis imperfecta results from Osseogenesis imperfecta?

Answer 29

-Type I

Question 30

What are the results of type III dentinogenesis imperfecta?

Answer 30

-Hypo-mineralization

Question 31

What causes type III dentinogenesis imperfecta?

Answer 31

-Failure of DSPP expression

Question 32

What origin are dentin cells?

Answer 32

-Mesenchymal

Question 33

T/F Odontoblasts continually secrete dentin throughout the course of their lives.

Answer 33

True

Question 34

What does the dentin-pulp complex arise from?

Answer 34

-Dental papilla

Question 35

When odontoblasts differentiate what zone to they fill?

Answer 35

-Acellular zone between the IEE and dental papilla

Question 36

T/F There is no vascular support for the developing Odontoblasts

Answer 36

False | -There is vascular support

Question 37

What is the interface between the enamel and dentin when they are in direct apposition?

Answer 37

-DEJ

Question 38

What type of edge does the DEJ have?

Answer 38

-Scallped

Question 39

What are two reasons the shape of the DEJ is critical?

Answer 39

- Define the shape of the crown | - Keeps denting directly attached to enamel during loading (no shearing)

Question 40

How is the DEJ bound together?

Answer 40

-Merging of the Enamel HA and the dentin HA in ridges

Question 41

What is the DEJ most pronounced?

Answer 41

-Under the crown

Question 42

What is the first layer of dentin formed?

Answer 42

-Mantle Dentin

Question 43

What is the only part of dentin that is not tubular?

Answer 43

-Mantle Dentin

Question 44

What type of fibers are .1-.2 mm collagen III fibrils that are associated with fibronectin during dentin formation?

Answer 44

-Von Korff's fibers

Question 45

Developing odontoblasts begin extending processes known as what?

Answer 45

-Tomes' fibers

Question 46

Where do the tome's fibers extend into?

Answer 46

-Developing matrix

Question 47

If the Mantle dentin penetrates the IEE what feature does that give?

Answer 47

-Enamel spindles

Question 48

What is the future odontoblast process?

Answer 48

-Tome's fibers

Question 49

What does dentin start as when it is deposited?

Answer 49

-Non-mineralized organic matrix known as predentin

Question 50

Where does mineralization start for dentin?

Answer 50

-within the Odontoblasts secreted matrix vesicles

Question 51

What are the two types of dentin mineralization?

Answer 51

- Globular | - Linear

Question 52

What happens to secreted matrix vesicles from dentin?

Answer 52

-They rupture and release mineralized matrix crystals

Question 53

What type of proteins regulate subsequent dentin formation that results in tubular primary dentin?

Answer 53

-Non-collagenous matrix proteins

Question 54

After the DEJ formation what type of dentin begins to form?

Answer 54

-Circumpulpal

Question 55

What initiates odontoblastic differentiation in the root?

Answer 55

-Hertwig's root sheath (HERS)

Question 56

What do HERS eventually break into?

Answer 56

-Cell rests of Malaxxez

Question 57

What is the first dentin formed during development that comprises the mantle dentin and the initial deposition of circumpulpal dentin?

Answer 57

-Primary Dentin

Question 58

What type of dentin is tubular dentin that is laid down subsequent to root formation?

Answer 58

-Seondary dentin

Question 59

How long is secondary dentin produced?

Answer 59

-Throughout life

Question 60

What section of dentin tubules have a sigmoidal curve?

Answer 60

-Coronal dentin

Question 61

What section of dentin tubules have a much straighter tube?

Answer 61

-Root dentin

Question 62

Does primary or secondary dentin have a sigmoidal curve?

Answer 62

-Primary

Question 63

When is tertiary dentin produced?

Answer 63

-In response to insult

Question 64

What is the purpose of tertiary (pathological) dentin?

Answer 64

- Seal off dentinal tubules - Form bridges between dentin and restoration - Response to trauma

Question 65

If the trauma does not damage odontoblasts what classification of tertiary dentin forms?

Answer 65

-Reactionary

Question 66

If the trauma damages damages odontoblasts what classification of tertiary dentin forms?

Answer 66

-Reparative

Question 67

What does the damage of odontoblasts do?

Answer 67

-Recruitment and differentiation of mesenchymal cells forming new odontoblasts

Question 68

What are the 3 main structures found in dentin?

Answer 68

- Dentin tubules - Peritubular dentin - Intertubular dentin

Question 69

T/F Tertiary dentin more resembles bone than dentin

Answer 69

True

Question 70

Where is the density of the dentin tubules higher at DEJ or near the Pulp?

Answer 70

-near the Pulp

Question 71

What are the dentin tubules surrounded by?

Answer 71

-Highly calcified peritubular dentin

Question 72

T/F Secondary branches can form from the dentinal tubules

Answer 72

True

Question 73

What is the response of the ondontoblasts when caries are traveling down the tubules?

Answer 73

-Tertiary dentin is formed

Question 74

When you seal off the dentin tubule with tertiary dentin and trap the air inside the tubule what is that known as?

Answer 74

-Dead tracts

Question 75

What is the collective term for tubules that have become occluded?

Answer 75

-Sclerotic dentin

Question 76

What does sclerotic dentin look like in a ground section?

Answer 76

- Glassy | - Translucent

Question 77

T/F As you get older you have less porous dentin

Answer 77

True

Question 78

What are areas of hypomineralized dentin known as?

Answer 78

-Interglobular dentin

Question 79

What is formed when fusion of mineral containing vesicles fail?

Answer 79

-Interglobular dentin

Question 80

What can interglobular dentin be associated with?

Answer 80

- Vitamin D deficiency | - Fluoride exposure during initial dentin formation

Question 81

Where is interglobular dentin more commonly found?

Answer 81

-Near mantle dentin

Question 82

Dentin matrix is deposited continually at how much per day?

Answer 82

-4 microns

Question 83

Every 5 days there is a layer of dentin deposited that has a noticeably different orientation of collagen fibers forming lines known as what?

Answer 83

-lines of von Ebner (Seen at 20 micron intervals)

Question 84

What are enhanced lines that indicate disruption of tooth formation?

Answer 84

-Contour lines of Owen

Question 85

Where do you find the Granular layer of Tomes?

Answer 85

-Root Dentin (more granular toward the apical end of tooth)