Pain Experience: Odontogenic Pain

Question 1

What sensations can we get from teeth and where do they come from?

Answer 1

Pain: dentine/pulp, PDL

Touch: PDL

Cold: gingiva, dentine/pulp

Question 2

What kind of pain should be felt when stimulating enamel?

Dentine?

Pulp?

Answer 2

Enamel: short, sharp pain in a healthy tooth

Dentine: short, sharp pain

Pulp: long, dull ache

Question 3

What is nerve fibres innervate the pulp?

What is the clinical relevance?

Answer 3

• 70-80% non-myelinated c-fibres

the rest: myelinated, of which:

• 90% A-delta fibres
• 10% are A-beta
• Plexus of Raschkow (in cell free zone)
• marginal plexus - around odontoblasts and into dentine

Clinical relevance: nerves branch to supply >1 tooth pulp - difficult to localise dentinal/pulpal pain

Question 4

Answer 4

Question 5

What influences pulpal pain?

Answer 5

• Neurones activated and sensitised by inflammatory mediators
• Substance P
• C-fibres

Question 6

What are the theories of dentinal sensitivity?

Answer 6

• dentine is innervated, detects stimulus and causes pain
• odontoblast receptor theory, odontoblast acting as receptor
• hydrodynamic theory

Question 7

Explain the hydrodynamic theory:

Answer 7

Stimuli that cause pain when applied to dentine:

• increase fluid flow in dentine in vitro
• generate action potentials in intradental nerves in vivo
• action potential rate linked to fluid flow