L5: Dentine-Pulp Complex

Question 1

what common ancestry do dentine and pulp share?

Answer 1

dental papilla

Question 2

what collagen types are present in dentine and pulp?

Answer 2

dentine: I
pulp: I, II, V

Question 3

does peripheral dentine have type IV collagen?

what is type IV collagen?

Answer 3

No,

basement membrane

Question 4

what type of dentinogenesis do existing odontoblast cells stimulate?

Answer 4

reactionary dentinogenesis

Question 5

what type of dentinogenesis requires progenitor cells from the pulpal tissues in order to be stimulated?

Answer 5

reparative dentinogenesis

Question 6

what is mantle dentine?

Answer 6

the first layer of dentine

Question 7

what is mantle dentine layed down by?

Answer 7

odontoblasts

Question 8

when is primary dentine formed?

Answer 8

it is formed by odontoblasts during the development of the tooth

Question 9

when is secondary dentine deposited?

Answer 9

slowly throughout the life of the tooth

Question 10

when is teritary dentine laid down?

Answer 10

rapidly on the pulpal aspect when there is occlusal wear/disease

Question 11

where is dentinal fluid derived from?

Answer 11

pulpal extracellular fluid

Question 12

What is the function of Dentin phosphoprotein (phosphophoryn) in mineralised dentine?

Answer 12

Modulates remineralisation

Question 13

How is dentine and pulp related?

Answer 13

They are functionally coupled and integrated as a united tissue

Question 14

What is the dentine pulp complex?

Answer 14

a dynamic tissue that responds mechanical, bacterial and chemical stimuli as a functional unit

Question 15

Where is the dentine-pulp complex found?

Answer 15

in the dentine surrounding the pulp

Question 16

What happens to the dentinal tubules in dentine closer to the pulp?

Answer 16

Number and size of dentinal tubules increases

Question 17

Why do the number of dentinal tubules increase as it moves closer to the pulp?

Answer 17

To allow communication between the dentine and pulp via nerves and odontoblast extentions

Question 18

How does tertiary dentine form?

Answer 18

Via communication through dentinal tubules by odontoblast processes, afferent nerve terminals and even processes of some immunocompetent cells

Question 19

what is the function of dentinal fluid?

Answer 19

supply nutrients and structural materials to dentine via pulpal blood vessels

Question 20

Which part of the tooth initiates an inflammatory response during dental disease?

Answer 20

dental pulp

Question 21

what happens to the dental pulp if infection continues to progress?

Answer 21

death of dental pulp

Question 22

What is the treatment following the death of dental pulp?

Answer 22

Endodontic treatment (pulp removal)

Question 23

What happens to the dentine with pulp removal?

Answer 23

Dentine becomes an inert tissue incapable of any response or repair

Question 24

Visually, what happens to the tooth when it becomes non vital?

Answer 24

discolouration

Question 25

Mechanically, what happens to the tooth when it becomes non vital?

Answer 25

fracture

Question 26

When is reactionary dentine formed?

Answer 26

During mild grades of injury, (shallow carious lesions/mild tooth wear related to erosion) the odontoblasts and other pulpal cells underlying the lesion may well survive, and are stimulated or upregulated to secrete a reactionary type of tertiary dentine

Question 27

What is reactionary dentine?

Answer 27

A wound-healing response to reconstruct circumpulpal dentine as a response to injury

Question 28

What is required during reactionary dentine formation?

Answer 28

stimulation of existing odontoblast cells

Question 29

What is reparative dentine?

Answer 29

The formation of dentine by a new generation of odontoblast-like cells which may consist of a "bridge" formation

Question 30

When is reparative dentine formed?

Answer 30

When pulp is exposed, deepening of the carious lesion

Question 31

What is required during reparative dentinogenesis?

Answer 31

Reparative dentinogenesis needs recruitment of progenitor cells from the pulpal tissue

Question 32

What happens to the dentinal fluid when cutting burs produce vibrations during endodontic treatment?

Answer 32

Causes inward and outward fluid shifts | = A CRISIS for dentin-pulp complex

Question 33

What happens following the fluid movement when cutting burs produce vibrations during endodontic treatment?

Answer 33

Barrage of hydrodynamic stimuli across the dentine into the dental pulp resulting in pain for the patient if not anaesthetised

Question 34

What happens to the cells in dentine during endodontic treatment?

Answer 34

Displacement of odontoblasts= disruption of their internal cytoskeleton = cell death

Question 35

What happens following cell death of odontoblasts?

Answer 35

cells are replaced by new odontoblasts over the next few days - If the dentine is sterile and well-sealed, displacement of odontoblasts and their replacement with new cells would cause no pulpal inflammation.

Question 36

list the stages of pulpal inflammation after a cavity prep

Answer 36

1. dentine not sealed well following a cavity prep 2. microleakage within the restoration 3. acute pulpal reactions into chronic stage due to MICRO-ORGANISMS and thier products