Dentine-Pulp Complex Flashcards

(51 cards)

1
Q

what is the dental pulp

A

the connective tissue ‘core’ of the tooth

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2
Q

what does the dental pulp contain

A
cells
extracellular components
nerves
blood vessels
lymphatics
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3
Q

what are the cells in the dental pulp

A

odontoblasts
fibroblasts
defence cells

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4
Q

what are the extracellular components of pulp

A

fibres (collagen, oxytalan)

matrix (proteoglycans, chondroitin SO4, dermatan SO4)

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5
Q

what are the nerves of the pulp

A
sensory
autonomic (sympathetic)
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6
Q

what are the functions of the dental pulp

A
nutritive (blood vessels)
dentine growth 
dentine repair
defence
neural
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7
Q

what is the function of the neural function of the dental pulp

A

sensory - pain - everything is felt as pain

control of dentinogenesis

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8
Q

what are the 3 types of links between dentine and pulp

A

developmental
structural
functional

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9
Q

what is the developmental link between dentine and pulp

A

they both develop from the dental papilla

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10
Q

what is the structural link between dentine and pulp

A

some plural elements extend into dentine

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11
Q

what pulpal elements extend into dentine

A
  • Odontoblast processes
  • Nerve terminals
  • Immune cells (dendritic cells)
  • Dentinal fluid
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12
Q

what are the functional links between dentine and pulp

A

formation of secondary dentine
formation of tertiary dentine in response to tooth wear (reactionary and reparative dentine)
regulate exchange of material between dentine and pulp

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13
Q

describe the hemodynamics and hydrodynamics of the pulp

A

fluid leaks from pulp capillaries into interstitial space due to pressure
fluid passes along dentinal tubules resulting in dentinal fluid
flow of dentinal fluid is proportional to pulp pressure
believed to have defence role

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14
Q

what are the different ways tooth wear can happen

A
o Mastication (abrasion) 
o Bruxism (attrition) 
o Abfraction (occlusal overload leads to fractures and cervical lesions) 
o Diet (erosion) 
o Caries – pathological
o Operative procedures
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15
Q

how can operative procedures result in tooth wear

A

 Occlusal equilibrium (used to cut teeth to give individuals a better occlusal arrangement)
 Cavity cutting; crown preparation etc – if this reaches dentine then this can cause a reaction

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16
Q

when is tertiary dentine formed

A

When you expose the dentine you may create a reaction of the dentine-pulp complex to produce dentine, this dentine is referred to as tertiary dentine

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17
Q

what is reactionary dentine

A

 It is in response to mild stimulus

 The response is mild and the dentine is laid down by primary odontoblasts

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18
Q

what is reparative dentine

A

 It is in response to intense stimulus that has destroyed the primary odontoblasts
 It is laid down by secondary odontoblasts (stem cells)

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19
Q

what can the odontoblast layer be considered as

A

a permeability barrier
separates the pulp and tubular space
regulates movement of material between the 2 - movement may be in either direction

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20
Q

what materials move from the pulp to the dentine

A

nutrients, to sustain cells
formation of secondary and tertiary dentine
potassium needed for function of tubular nerves

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21
Q

what materials move from dentine to pulp

A

medicaments applied to dentine

diffusion of toxins from bacteria, components of filling materials

22
Q

what nerves supply the pulp

A

alveolar nerve

23
Q

describe the anatomy of the pulp nerves

A

 Neurovascular bundles enter pulp via the apical foramen and pass along the root canal in the center of pulp towards the coronal pulp chamber
 The branches fan out in the sub-odontoblastic layer to form plexus of Raschkow
Terminal branches enter the odontoblast layer, some nerves enter the dentinal tubules

24
Q

what % of tubules under cusps contain nerves

25
why do more cusp tubules have nerves
cusp tubules have more as they have a sensorial function, a monitory system inside the tooth to generate a response if there is more tooth wear, stimulating the pulp to form tertiary dentine
26
how far do axons extend in the cusp tubules
100-200 nanometres
27
what is the % of tubular innervation in coronal dentine
15
28
what is the % of tubular innervation in root dentine
4
29
what is name of the mechanism for activating interdental sensory nerves
hydrodynamic mechanism
30
where do most axons end in coronal and root dentine
pulp-predentine region
31
what is the hydrodynamic mechanism
1. Stimulus (thermal, mechanical, evaporative, chemical) acts on exposed dentine (open tubules) 2. This increases the rate of dentinal fluid flow 3. This causes the generation of action potentials in intra dental nerves 4. These action potentials pass to the brain to cause pain
32
what are the two directions of dentinal fluid flow
outward | inward
33
what causes outward fluid flow
cooling, drying, evaporation, hypertonic solutions, decreased hydrostatic pressure
34
what causes inward fluid flow
heating, mechanical, increased hydrostatic pressure
35
what type of fluid flow is more effective at activating intradentall nerves and why
outward | outward movement stretches the axons causing generation of an action potential
36
what stimuli bypass the hydrodynamic mechanism and act directly on the interdental nerves
intense heating intense cooling electrical current pain-producing chemicals
37
how can high fillings cause dentinal pain
force distorts the dentine and alters tubular flow
38
what do Abeta and Adelta fibres do
activated by hydrodynamic stimuli applied to dentine | probably mediate normal dentinal sensitivity
39
what do c fibres do
o Probably activated directly by stimuli, rather than hydrodynamic mechanism o They respond to most forms of intense stimuli o Probably mediate pain associated with pulp inflammation (e.g caries)
40
what is the blood supply to teeth
branches of the maxillary artery
41
what is pulp blood flow controlled by
local factors nerves circulating hormones drugs
42
what can use of an uncooled bur with high speed motor cause
irreversible damage to the pulp as it can dramatically reduce blood flow and so benefits of the circulation will be eliminated which starves the pulp causing it to inflame
43
what does pulp infammation result in
causes an increase in pressure due to swelling but there is no room to expand unlike normal tissue where there is expansion. The pulp cannot swell due to constraint and so the ability of exchange of nutrients will be effected ultimately causing necrosis
44
what are the function of the pulp nerves
``` sensory control of pulp blood vessels promote neurogenic inflammation promote dentine formation facilitate immune response ```
45
what is the immediate dentine pulp response to injury
Nociceptor activation – pain
46
what is the response to injury after 1 minute
 Early inflammatory response |  Vasodilation
47
what is the response to injury after 10 minutes
 Nociceptor sensitization  Extravasation of fluid, oedema  Polymorph migration
48
what is the response to injury after 100 minutes
 Enzyme activation |  Monocyte presence
49
what is the response to injury after 1 day
 Nerve sprouting (NGF)  Increased axonal transport  Altered excitability of CNS synapses
50
what is the response to injury after a week
 Repair; tertiary dentine formation
51
describe pulpitis
 acute inflammation in the dental pulp is similar to that in other tissues except that the pulp cannot swell as it is confined to the pulp chamber  oedema causes an increase in pulp pressure  this can have variable effects on blood flow and on nerve excitability