(4) Dentinal-pulpal complex - dentine variations in structure

Question 1

What is the first layer of dentin to form and the most peripheral?

Answer 1

Mantle dentin

Question 2

what are the 7 structures in dentin?

Answer 2

Question 3

What is the width of mantle dentine?

Answer 3

20-150um

Question 4

what direction does dentin form?

Answer 4

Inwards

Question 5

does mantle dentin form throughout life?

Answer 5

Yes

Towards the pulp

Question 6

what is mantle dentin adjacent to?

Answer 6

Enamel

Question 7

what is the circumpulpal dentin?

Answer 7

All the dentin form the mantle dentin

Question 8

what is the most mineralised part of dentin?

Answer 8

The circumpulpal dentin

Question 9

What is more mineralised; mantle or circumpulpal dentine?

Answer 9

Circumpulpal dentine by 5%

Question 10

what is the direction of the collagen fibres in the mantle dentin?

Answer 10

Perpendicular on the amelo-dentinal junction

Question 11

Does the mantle dentin have a lot of looping of tubules?

Answer 11

Yes

Because of the branching of the odontoblastic processes at the beginning of the dentine formation

Question 12

How is mantle dentin mineralised?

Answer 12

Through small vesicles with crystals inside them

Question 13

what type of section is this?

Answer 13

Ground section

Question 14

Answer 14

Question 15

Answer 15

A = enamel
B = mantle dentin
C = circumpulpal dentine (primary curvature)

Arrows = interglobular dentin

Question 16

what is interglobular dentin?

Answer 16

Area which is hypomineralised and jut under the mantle dentin

Minerals deposited as globules (calcospheres)

Question 17

how does mineralisation occur in dentin?

Answer 17

globules which fuse together

Fuse to form a uniform calcified tissue

Question 18

When does interglobular dentin form?

Answer 18

If globules fail to fuse together to form dentin

Question 19

How does interglobular dentin compare to the rest of the dentin with regard to mineralisation?

Answer 19

just like normal dentin but is not as highly mineralised as threat of the dentin

Question 20

What passes through the interglobular dentin?

Answer 20

Tubules

Question 21

why do the interglobular dentin appear dark in a section?

Answer 21

The light passes through them

Question 22

Answer 22

Interglobular dentin

Question 23

Where is there lots f branching of the dentinal tubules and what occurs?

Answer 23

In the roots

So much branching creates loops

Question 24

What happens when loops are formed in the roots? (Section)

Answer 24

Air gets trapped in ground sections and reflect the light and they appear dark

Question 25

What are the dentinal tubule loops called in the roots?

Answer 25

Granular layer of Tome

Question 26

Is the granular layer of Tomes hyper or hypomineralised?

Answer 26

hypomineralised

Question 27

Answer 27

A = acellular cementum B = granular layer of tomes C = cementum (granular layer of Tomes)

Question 28

Answer 28

A = dentin B = granular layer of tomes C = hyaline layer D = acellular cementum

Question 29

What is the width of the hyaline layer?

Answer 29

Up to 20um

Question 30

Where do you find the hyaline layer in the tooth?

Answer 30

The root The crown has mantle dentin

Question 31

What is the role of the hyaline later?

Answer 31

Helps bonding dentin to cementum

Question 32

what does the hyaline layer lie outside of?

Answer 32

Granular layer of tomes

Question 33

What is the structure of circumpulpal dentin?

Answer 33

Uniform in structure except at peripherals

Question 34

What is predentine?

Answer 34

initially laid dentin matrix prior to mineralisation

Question 35

how does mineralisation of predentin occur in predentin?

Answer 35

In globules or a linear appearance

Question 36

What is the width of predentine?

Answer 36

10-40um in width

Question 37

is predentine thicker in young or older teeth?

Answer 37

Younger

Question 38

Answer 38

Question 39

What does the predentin always lie next to?

Answer 39

The pulp

Question 40

What is mantle dentin always net to?

Answer 40

The enamel

Question 41

What is the mineralisation front?

Answer 41

The interface between the fully mineralised dentin and newly formed dentin