ORE Part 1 Pharmacology in Dentistry

Question 1

What is the mechanism of action of articaine, the most widely used local anaesthetic in UK dental practice?

Accepted Answer

Blocks voltage-gated sodium channels in the neuronal membrane, preventing action potential propagation and nerve conduction

Answer

Stimulates GABA receptors to inhibit pain transmission

Answer

Blocks calcium channels to reduce neurotransmitter release

Answer

Acts centrally on the thalamus to reduce pain perception

Question 2

What concentration of articaine is most commonly used for dental local anaesthesia?

Accepted Answer

4% articaine with 1:100,000 adrenaline

Answer

2% lignocaine alone

Answer

0.5% bupivacaine

Answer

10% lignocaine topical only

Question 3

Why is adrenaline (epinephrine) added to dental local anaesthetic cartridges?

Accepted Answer

To cause vasoconstriction, reducing systemic absorption, prolonging duration of anaesthesia, and providing a bloodless operative field

Answer

To increase the speed of anaesthetic onset

Answer

To reduce the risk of allergic reaction

Answer

To reduce the pH of the solution

Question 4

What is the maximum safe dose of lidocaine (lignocaine) with adrenaline in a healthy adult?

Accepted Answer

7 mg/kg (up to 500 mg maximum)

Answer

3 mg/kg (up to 200 mg)

Answer

10 mg/kg

Answer

1 mg/kg only

Question 5

A patient is taking a non-selective MAOI antidepressant. What dental anaesthetic concern arises?

Accepted Answer

Adrenaline should be used with extreme caution or avoided — MAOIs potentiate catecholamine effects, risking severe hypertension

Answer

MAOIs increase the risk of LA allergy

Answer

MAOIs cause LA to be ineffective

Answer

No concern — MAOIs have no effect on dental anaesthetics

Question 6

Which local anaesthetic has the longest duration of action, useful for postoperative analgesia?

Accepted Answer

Bupivacaine (Marcain) 0.5%

Answer

Lidocaine

Answer

Mepivacaine

Answer

Articaine