OB- Dentine Pulp complex

Question 1

Compare the vascularisation of dentine and pulp?

Answer 1

Pulp is vascularised,

Dentine is not vascularised. It is protected by an odontoblast layer that prevents penetration (so dentine doesn’t bleed)

Question 2

How is the development of dentine and pulp linked?

Answer 2

They both develop from the dental papilla.

Question 3

How is the structure of dentine and pulp linked?

Answer 3

There are elements from the pulp that extend into the dentine e.g. odontoblast processes

Question 4

How are the functions of dentine and pulp linked?

Answer 4

To regulate the exchange of material

To form secondary and tertiary dentine.

Question 5

What is reactionary dentine?

Answer 5

A tertiary dentine that responds to a mild stimulus. It is laid down by primary odontoblasts

Question 6

What is reparative dentine?

Answer 6

A tertiary dentine that is produced in response to an intense stimuli. This is laid down by secondary odontoblasts.

Question 7

What is the function of the odontoblast layer?

Answer 7

This acts as a permeability layer regulating the movement of material between the pulp and the dental tubules

Question 8

What materials are exchanged from the pulp to the dentine?

Answer 8

Nutrients

Secondary and tertiary dentine

Pottassium

Question 9

What is the nerve supply of the pulp?

Answer 9

Alveolar nerve branches.

Question 10

Describe the route of the pulp nerves?

Answer 10

They enter the pulp via the apical foramen

Pass along the root canal in the centre of the pulp

Towards the coronal pulp chamber.

Question 11

What is raschow’s Plexus?

Answer 11

When the pulp nerve branches fan out in the sub-odontoblastic layer.

Question 12

What is neurogenic inflamation?

Answer 12

The activation of the nerves and the release of inflammatory agents.

Question 13

Where would you find more tubular nerve innervation in dentine?

Answer 13

Under the cusps.

Question 14

Describe the hydrodynamic mechanism?

Answer 14

This is how tooth pain is felt.

Exposed dentine (damaged) causes the dentinal tubules to open.

This increases the rate of dentinal fluid flow which generates the Action potential in the intra dental nerves.

Pain signals are sent to the brain.

Question 15

What fluid flow direction results in a greater pain feeling and why?

Answer 15

The flow of fluid away from the pulp as it stretches the axon, putting it under more pressure and activating the intra dental nerves.

Question 16

What fibres are activated by hydrodynamic stimuli?

Answer 16

A β and Aδ fibres

Question 17

Why does pain occur from a high restoration?

Answer 17

The force caused by biting down on a high restoration (filling or crown) causes the dentine to distort. This alters the tubular flow causing pain..

Question 18

What supplies blood to the teeth?

Answer 18

Branches of the maxillary artery.

Question 19

Why do we use water spray when using a burr?

Answer 19

To cool down the burr in order to prevent pulp damage (it is sensitive to heat)

Question 20

Describe the Dentine- pulp injury response?

Answer 20

1. Activation of nociceptors - causing pain
2. Inflamation begins & cells are recruited (to cause vasodilation)
3. Sensitisation of nociceptors, extravasation of fluid & polymorph migration
4. Activation of enzymes and nerve growth fibres (for re-organisation of nerves)
5. Sprouting of nerve fibres (increasing axonal transport and altering CNS excitability)
6. Formation of teritary dentine for tooth repair.

All Irish Speak And Sing Fast.

Question 21

How do we tell the difference between primary and secondary dentine in an image?

Answer 21

The change of direction of the dentinal tubules shows us where primary dentine stops and secondary dentine starts.

Question 22

Compare the dentinal tubules closer to the pulp to those further away.

Answer 22

A-Dentinal tubules located close to the pulp have a wider diameter and are closer together (because there is less room around the pulp)

B-Dentinal tubules further away are thinner and further apart