Dentine and Pulp

Question 1

Which substance of tooth forms the bulk of the tooth?

Answer 1

Dentine

Question 2

What is dentine harder and softer than?

Answer 2

• Harder then bone and cementum but softer than enamel

Question 3

What has a greater compressive and tensile strength: enamel or dentine?

Answer 3

Dentine

Question 4

What aspect of dentine makes it permeable?

Answer 4

It contains tubules

Question 5

What is tensile strength?

Answer 5

Ability to resist tension and sharing forces

Question 6

What is compressive strength?

Answer 6

Resist to compression, lower then enamel
- Dentine is able to cushion effect of sharing forces on enamel so able to absorb the force for enamel as sifter - work together - resist abrasion and sharing forces on tooth

Question 7

What is the hydroxyapatite content of dentine?

Answer 7

70% weight (50% volume)

Question 8

What is the water content of dentine?

Answer 8

10% weight (20%) volume

Question 9

What is the organic matrix content of dentine?

Answer 9

20% weight (30% volume)

Question 10

What does the primary curvature of dentine look like?

Answer 10

• S-shaped

Question 11

What is the secondary curvature of dentine?

Answer 11

• Wavy

Question 12

Does dentine form inwards or outwards?

Answer 12

Forms at ADJ and moves inwards to pulp

Question 13

What is primary dentine?

Answer 13

Formed when tooth begins to form

Question 14

What is secondary dentine?

Answer 14

Formed once tooth is fully formed

Question 15

What is tertiary dentine?

Answer 15

Formed after damage has been done to tooth

Question 16

What cells produce dentine?

Answer 16

Odontoblasts

Question 17

What is pre-dentine?

Answer 17

Non mineralised dentine

Question 18

What are the contents of dentinal tubules?

Answer 18

• Odontoblast process
• Unmyelinated nerve terminals
• Dendritic cells (immune system)
• Dentinal fluid or ECF from pulp

Question 19

What are proteoglycans?

Answer 19

• Proteins with sugar side chains

- They absorb water

Question 20

What is the connective tissue ‘core’ of the tooth?

Answer 20

Dental pulp

Question 21

What are the cells present in the dental pulp?

Answer 21

• Odontoblasts
• Fibroblasts
• Defence cells

Question 22

What are the extracellular components of dental pulp?

Answer 22

• Fibres (collagen, oxytalan)

- Matrix (proteoglycans, chondroitin SO4, dermatan SO4)

Question 23

What nerves are found within the dental pulp?

Answer 23

• Sensory; autonomic (sympathetic)

Question 24

Does dental pulp contain blood vessels and lymphatics?

Answer 24

Yes

Question 25

What are the functions of dental pulp?

Answer 25

• Nutritive (feeds odontoblasts to allow them to produce dentine)
• Dentine growth
• Dentine repair
• Defence (immune cells; lymphatics)
• Neural (sensory, control of dentinogenesis)