ADC PART 1 · FREE TRIAL · DAY 1 · SESSION 2
ADC Part 1 · Free Trial · Day 1
Session 2 of 4 · The Alexander Case — Q1 through Q5 · 60 minutes
Session 2 — Live walkthrough
Session 1 gave you the framework. Now you are going to see it applied to a real ADC vignette — question by question, reasoning step by step.
Read all five questions and the explanations first. Then watch the video — where you will see the wrong reasoning demonstrated before the correct reasoning, so you can feel exactly what the examiner is trying to catch.
The Official ADC Sample Vignette
The Alexander Case
This is the only vignette the ADC has ever released publicly. Read it carefully. Every detail is clinically significant.
Alexander, a 64-year-old patient who is receiving warfarin as part of the management of his atrial fibrillation, tells you that one of his lower right back teeth was restored three years ago by a dentist who has since retired from your practice. The tooth is now occasionally sensitive to hot and cold. The clinical notes confirm the history and indicate that the tooth was restored using a resin composite material. You obtain a periapical radiograph.
Five questions follow. For each one you will see the correct answer, the reasoning chain that gets you there, and the cognitive error the examiner built into the wrong options.
Question 1 · Information Gathering · Cluster C2
Which additional test is most appropriate to assist in making a diagnosis?
In addition to testing the pulp vitality with either cold or an electric pulp tester, which of the following clinical tests or procedures would be the most appropriate to assist in making a diagnosis?
Correct reasoning chain
Vitality testing is already being done. The diagnostic question is: has the periapical region been affected? The percussion test answers that directly — a positive response indicates periapical involvement. No other option on this list answers that specific question.
Why the wrong options fail
A — OPG: you already have a periapical. Higher dose, lower resolution for a single tooth. ARPANSA requires individual justification.
B — Bitewing: useful for caries detection. Does not assess periapical status.
D — Crack test: nothing in the vignette indicates a crack. Do not apply a test for a condition without clinical indication.
E — INR: relevant to treatment planning, not to making a pulpal diagnosis. Wrong stage.
⚡ Examiner trap
Candidates select D (crack test) reasoning that composites can cause crack sensitivity. Plausible — but there is no clinical evidence of a crack in this vignette. Applying a test for an unindicated condition is the trap.
Question 2 · Diagnosis · Cluster C3
What is most likely to cause the failure of the Class II composite?
Correct reasoning chain
The gingival seat of a proximal box sits on dentine or cementum — not enamel. Bonding to dentine is less reliable and more moisture-sensitive. Polymerisation shrinkage pulls the material away from exactly this margin. The gingival margin of the proximal box is the most predictable, documented primary failure site of a Class II composite.
Why the wrong options fail
A — Incremental placement causes leakage: this reverses the evidence. Incremental placement reduces shrinkage stress. It does not cause leakage.
C — Occlusal loads/flexure: real but secondary. Plausible for clinicians with experience — this is the most appealing distractor. The gingival margin failure is the primary mechanism.
D — Extended curing causes greater shrinkage: factually reversed. Longer curing improves monomer conversion and reduces residual shrinkage.
⚡ Examiner trap
Candidates with good clinical experience select C (occlusal flexure) because it matches what they see in practice. The examiner knows this. C is true but secondary. The trap is selecting the plausible answer over the primary evidence-based failure mode.
Question 3 · Diagnosis · Cluster C3
What sensitivity description would you expect Alexander to report?
Given the history and radiographic evidence, what is the best description of the sensitivity to hot and cold you would expect Alexander to report?
Correct reasoning chain
The question asks you to read the clinical picture — not just recall pain descriptions. Three-year-old composite, gingival margin failure, ongoing microleakage, bacterial ingress. This tooth is progressing toward irreversible pulpitis. Irreversible pulpitis has one diagnostic hallmark: pain that lingers after the stimulus is removed. Dull, lingering 1–2 minutes. That is option C. The word to look for is lingering.
Why the wrong options fail
B — Sharp, relieved on removal: this is reversible pulpitis. The clinical picture points beyond reversible pulpitis.
D — Always present, worse with stimulus: this is acute pulp necrosis or abscess — constant pain. Alexander reports occasional sensitivity, not constant pain.
E — Worse in the morning: not a recognised dental pulpal pain pattern.
⚡ Examiner trap
Candidates select B (sharp, relieved on removal) because it is the most commonly taught description of dental sensitivity. The trap is applying the reversible pulpitis pattern when the clinical picture points beyond it. The discriminating cue is the word lingering in option C.
Question 4 · Treatment · Cluster C4
INR is 2.4. What is the most appropriate action?
You have decided to extract the tooth and in planning for the procedure you find that the patient's International Normalized Ratio (INR) is 2.4. What is the most appropriate action to take at this time?
Correct reasoning chain
INR 2.4 is within the therapeutic range for atrial fibrillation (2.0–3.0). The Therapeutic Guidelines September 2025 are explicit: do not stop warfarin for simple dental extractions with INR within therapeutic range. The thromboembolic risk of stopping warfarin in an AF patient — stroke, systemic embolism — significantly outweighs the bleeding risk from a simple extraction managed with local haemostatic measures. Proceed. Apply haemostatic measures. Give post-operative instructions.
Why the wrong options fail
B — Stop warfarin 3 days: creates a sub-therapeutic window in a high-risk cardiac patient. Directly contradicts TG Sept 2025.
C — Stop warfarin, start aspirin: aspirin adds antiplatelet effect on top of reduced anticoagulation. Clinically dangerous.
D — Consult cardiologist to stop warfarin: not required for simple extraction with INR in therapeutic range. Over-escalation.
E — Refer to OMFS: a single-tooth extraction is within GP scope. This is not a complex surgical problem.
⚡ Examiner trap
Candidates select D or E — warfarin plus cardiac history feels like a specialist problem. The trap is appropriate caution applied incorrectly. The Australian standard is clear: INR within therapeutic range, simple extraction, proceed with local haemostatic measures.
Question 5 · Professionalism & Autonomy · Cluster C1
Which prosthodontic option is most appropriate after extraction?
After removal of tooth 46, which prosthodontic option would be most appropriate for Alexander?
Correct reasoning chain
Q5 is always the professionalism and autonomy cluster. This question is not testing your prosthodontic knowledge. It is testing whether you understand that the decision to replace a missing tooth belongs to Alexander — not to you.
You do not know whether Alexander is bothered by the gap, whether he has aesthetic concerns, or what his priorities are. The Australian standard requires that the patient be given the opportunity to experience the result and form a view before a replacement plan is prescribed. Options A through D all prescribe a treatment before the patient has been consulted. Option E does not. It respects autonomy.
Why the wrong options fail
A — Immediate implant: no implant assessment has been performed. Bone quality, systemic suitability, and patient preference are unknown.
B, C — Immediate or delayed RPD: prescribes a specific solution before the patient has assessed their own need.
D — Fixed bridge: assumes abutment suitability without assessment, and prescribes without patient input.
⚡ Examiner trap — the most dangerous in the entire case
Candidates select C (RPD after healing) believing they are being clinically responsible. It sounds conscientious. It sounds like planning. It is wrong because it treats the replacement decision as the clinician's to make. Prescribing C without patient input fails the autonomy cluster. The question the examiner is actually asking is: whose decision is this?
Watch now
The Alexander Case — Live Walkthrough
12 minutes · Wrong reasoning shown first, then correct · Direct to camera
▶
[ Replace this block with your video embed ]
You have already read the explanations. The video shows the live reasoning process — including the wrong way first.
What This Case Teaches
Five questions. One patient. The same methodology applied every time:
Identify which cluster the question is testing before selecting an answer
Apply the Australian benchmark — TG Sept 2025, ARPANSA, AHPRA — not clinical instinct
Recognise the trap — the most appealing wrong answer is always plausible. That is the point.
Q5 is always professionalism — prepare for it as a category, not a surprise
Session 2 complete
You have now seen the methodology in practice.
Session 3 is the trial exam.
Twenty questions. Thirty minutes. No explanations until you submit. When you do, your results dashboard will show your performance by cluster, by difficulty, and by trap category — the first honest measure of where you stand.