OCB02-1017 Dentinogenesis

Question 1

What is dentineogenesis?

Answer 1

Formation of dentine

Question 2

Where does dentineogenesis occur?

Answer 2

Dental papilla

Question 3

What cells perform dentineogenesis?

Answer 3

odontoblasts

Question 4

When does dentineogenesis occur?

Answer 4

Later bell stage

Question 5

What do differentiating odontoblasts undergo rapid changes in?

Answer 5

size and polarisation

Question 6

Where does cytodiffrentiation start?

Answer 6

tip of cusps or incised margins, and travels rootwards

Question 7

What is the structure of the odontoblast?

Answer 7

Large nucleus at the basal part

Many small cell processes directed towards the basement membrane

Question 8

Where is the predentine?

Answer 8

In the space between the odontoblast cell body and mental dentine

Question 9

What colour is the staining of pre dentin?

Answer 9

Pale

Question 10

What is another term for mineralisation front?

Answer 10

Metadentine

Question 11

What is the mineralisation front?

Answer 11

It is part of the predentine, directly below mineralised dentine

Question 12

What do odontoblast processes secrete?

Answer 12

Dentine phosphoprotein
Dentine sialophosphoprotein
Minerals associated with proteoglycans

Question 13

Where does mineralisation start?

Answer 13

With mantle dentin and moves towards circumpulpal dentin

Question 14

What occurs when the odontoblast secretes mantle dentin?

Answer 14

It buds off matrix vesicles which are 30-200nm in diameter

Question 15

What is the purpose of alkaline phosphatase in the vesicles of mineralisation?

Answer 15

They increase PO43- concentration to develop crystals

Question 16

Where are crystalline structures only present in?

Answer 16

Mantle dentine

Question 17

What is controlled to control odontoblasts?

Answer 17

Controlling influx of Ca2+ ions

Controlling secretion and metabolism of matrix proteins

Question 18

How does mineralisation of circcumpulpal dentine occur?

Answer 18

By Ca2+ nucleation at spaces present with bundles of collagen

Question 19

What controls mineralisation of circumpulpal dentine?

Answer 19

DPP

Dentine phosphoprotein

Question 20

What does it mean by circupulpal dentine having a linear mineralisation front?

Answer 20

The calcification of dentine appears uniform

Question 21

What are the properties of DPP?

Answer 21

Highly acidic so binds to Ca2+

Can change shape to bind Ca2+ ions to allow crystal growth

Question 22

What are the functions of DPP?

Answer 22

Transports Ca2+ to mineralisation front
Stabilisation of formed crystals
Inhibits crystal formation in high concentration

Question 23

What are the proteins of odontoblasts?

Answer 23

Osteonectin
Osteopontin
Boe Sialoprotein
Proteoglycans

Question 24

What does osteonectin do?

Answer 24

Inhibits growth of hydroxyapatite and promotes Ca2+ and Po4 3- binding to collagen

Question 25

What does osteopontin do?

Answer 25

Promotes mineralisation

Question 26

Where is bone sialoprotein found?

Answer 26

Early mineralising dentine, predentine and peritubular dentine

Question 27

What are circular areas of mineralisation called?

Answer 27

Calcospherites

Question 28

What are areas where calcospherites fail to fuse called?

Answer 28

Interglobular dentine

Question 29

When does the peritubular dentine layer form?

Answer 29

Same time as interlobular dentine

Question 30

What is root dentine initiated by?

Answer 30

The formation of HERS

Question 31

How does the rate of formation of root dentine differ to coronal dentine?

Answer 31

Root dentine forms slower than coronal dentine

Question 32

What is mineralisation like in multicoated teeth?

Answer 32

They have isolated areas of mineralisation

Question 33

What are the properties of root dentin (hyaline layer)?

Answer 33

No dentinal tubules | Non-collageous fibrillar matrix

Question 34

What signalling molecules are in tertiary dentine formation?

Answer 34

TGF-B