ORE Part 1 Medical Sciences — Questions and Answers
Question 1: A patient with a known cardiac murmur is scheduled for dental extraction. According to current NICE guidelines, what is the recommended antibiotic prophylaxis regimen?
- Amoxicillin 3g orally one hour before
- Clindamycin 600mg orally one hour before
- No routine antibiotic prophylaxis is recommended (Correct answer)
- Azithromycin 500mg orally one hour before
Correct answer: No routine antibiotic prophylaxis is recommended
NICE Clinical Guideline CG64 (updated) states that antibiotic prophylaxis against infective endocarditis is NOT routinely recommended for dental procedures in the UK, regardless of the cardiac condition. This differs from American Heart Association guidelines and is a key point for the ORE examination.
Question 2: Which coagulation pathway is assessed by the prothrombin time (PT) and INR?
- Intrinsic pathway
- Extrinsic pathway (Correct answer)
- Common pathway only
- Fibrinolytic pathway
Correct answer: Extrinsic pathway
The PT/INR assesses the extrinsic and common coagulation pathways (factors VII, X, V, II, and fibrinogen). It is the standard monitoring test for warfarin therapy. The APTT, by contrast, assesses the intrinsic pathway and is used to monitor heparin therapy.
Question 3: A diabetic patient becomes sweaty, confused, and tremulous during a dental appointment. What is the most appropriate immediate management?
- Administer intramuscular adrenaline
- Give oral glucose gel or a sugary drink if conscious (Correct answer)
- Place patient supine and wait
- Administer sublingual GTN
Correct answer: Give oral glucose gel or a sugary drink if conscious
These are signs of hypoglycaemia. If the patient is conscious and can swallow, the immediate treatment is oral glucose (glucose gel, tablets, or a sugary drink such as orange juice). If unconscious, intramuscular glucagon 1mg should be administered. This is a core medical emergency scenario for the GDC.
Question 4: What is the correct dose of intramuscular adrenaline for an adult experiencing anaphylaxis in a dental surgery?
- 0.1ml of 1:1000 (0.1mg)
- 0.5ml of 1:1000 (0.5mg) (Correct answer)
- 1ml of 1:10,000 (0.1mg)
- 1ml of 1:1000 (1mg)
Correct answer: 0.5ml of 1:1000 (0.5mg)
The Resuscitation Council (UK) guidelines recommend 0.5ml of 1:1000 adrenaline (500 micrograms) given intramuscularly into the anterolateral thigh for adult anaphylaxis. This can be repeated every 5 minutes if there is no improvement. Intravenous adrenaline should only be given by experienced specialists.
Question 5: Which hepatitis virus is most commonly transmitted through needlestick injuries in the dental setting?
- Hepatitis A
- Hepatitis B (Correct answer)
- Hepatitis C
- Hepatitis D
Correct answer: Hepatitis B
Hepatitis B has the highest transmission rate via needlestick injury (approximately 30% from an infected source), compared to hepatitis C (approximately 3%) and HIV (approximately 0.3%). This is why hepatitis B vaccination is mandatory for all dental healthcare workers in the UK.
Question 6: A patient taking a selective serotonin reuptake inhibitor (SSRI) attends for dental treatment. Which drug interaction is most relevant in dentistry?
- Increased bleeding risk due to impaired platelet function (Correct answer)
- Reduced efficacy of local anaesthetic
- Hypertensive crisis with adrenaline-containing LA
- Increased risk of cardiac arrhythmia
Correct answer: Increased bleeding risk due to impaired platelet function
SSRIs inhibit serotonin reuptake into platelets, impairing platelet aggregation and increasing bleeding risk, particularly when combined with other antiplatelet agents or NSAIDs. Dentists should be aware of prolonged bleeding times and exercise caution during surgical procedures.
ORE Part 1 Medical Sciences
A patient with a known cardiac murmur is scheduled for dental extraction.
According to current NICE guidelines, what is the recommended antibiotic prophylaxis regimen?