Dentine

Question 1

Where is Peritubular dentine?

Answer 1

Walls of tubules Highly mineralised Also known as intratubular dentine

Question 2

Where is Intertubular dentine?

Answer 2

Between the tubules Highly mineralised Forms the bulk of dentine around the dentinal tubulesWhat

Question 3

Where is Mantle dentine?

Answer 3

Outermost layer along the DEJ First dentine formed in a band of 150um wide Is mineralised by matrix vesicleswhat is granular layer of Tomes

Question 4

What is Primary dentine?

Answer 4

Forms prior to eruption Rapidly formed more mineralised than secondary Contains incremental lines

Question 5

What is secondary dentine?

Answer 5

Formed after completion of root formation Formed slower & less mineralised than primary Increases the thickness of dentine Causes the canals to get smaller over time

Question 6

What is Tertiary dentine?

Answer 6

Formed as a result of injury/trauma Traumatic cavity prep Irregular pattern of tubules

Question 7

What is granular layer of Tomes?

Answer 7

Thin layer of dentin adjacent to the cementum Only root surface Just beneath the Hyaline layer Branching and looping of tubules

Question 8

What is Contour lines of Owen?

Answer 8

Accentuated incremental lines in the dentin thought to be due to disturbances in the mineralization process. Only found in the crown area

Question 9

What is globular dentine?

Answer 9

Layer between the mantle & circumpupal Only in Crown coronal portion This form of dentin is hypomineralized

Question 10

What are the 3 types on dentine

Answer 10

Primary Secondary Tertiary

Question 11

What does peritubular dentine consist of?

Answer 11

Lacks collagen fibrous matrix 15% more mineralised than intertubular Crystals-carbonated apatite

Question 12

What is in the root layer of dentine?

Answer 12

Hyaline layer - Glass like or clear lies just outside the granular layer Grandular layer of Tomes - in the root not crown Circumpupal dentine

Question 13

What is in the crown layer of dentine?

Answer 13

Mantle dentine - The outer most layer of dentine Interglobular dentine - where minerals are deposited Circumpupal dentine - Bluk of dentine

Question 14

What is the Hyaline layer?

Answer 14

Most peripheral layer initially unmineralised dentine 0.5-0.8 μm thick Contains enamel matrix-like protein Initial fibers of the periodontal ligament embed Aids cementum in binding to the dentine Very narrow, non-tubular structure-less band

Question 15

What chemicals are in Interglobular dentine?

Answer 15

Sulfur - see in crown

Question 16

What chemicals are in Tomes granular layer?

Answer 16

Calcium & Phosphorus - see in root

Question 17

What is Predentine?

Answer 17

The innermost layer of dentine 10 to 40 μmin thickness Thicker in young teeth Non-mineralised Always adjacent to pulp tissue Very Pale in colour

Question 18

What is Predentine composed of?

Answer 18

Collagen & proteoglycans secreted produce Metadentin Matrix deposition precedes mineralisation Secreted by odontoblasts ◦Golgi apparatus◦Mitochondria

Question 19

What is Translucent dentine?

Answer 19

Forms with aging due to tubule occlusion by peritubular dentine Found at the root apex Used in forensic dentistry to tell age

Question 20

What is Sclerotic dentine?

Answer 20

Tubular occlusion by a stimulus Similar appearance to translucent dentine but related in site to the stimulus

Question 21

What does Sclerotic dentine do?

Answer 21

They can just shut down, this is believed to be a protective mechanism to pulp & increase with age

Question 22

What are Dead tracts?

Answer 22

When dentine is damaged, odontoblastic processes die or retract leaving empty dentinal tubules, termed dead tracts DT When the dentinal tubules are opened or sufficiently irritated, their contents coagulate and die.

Question 23

How do we get Dead tracks?

Answer 23

What dentine is damaged odontbalstic process dies leaving empty tubules DT Odontoblastic processes killed by a stimulus Empty tubules

Question 24

What do Dead tracks look like?

Answer 24

Appear dark under transmitted light microscope

Question 25

What are the layers of dentine?

Answer 25

Question 26

Looking at the layers of detnine.

Answer 26