BDS Viva: How to Answer, Not Just What to Know

In short: Examiners test reasoning and safety, not recall — questions escalate until they find your ceiling, and that is by design. Structure answers aloud, reason through clinical questions step by step, pause before answering, never bluff, and practise the clean "I don't know, but here is what I do know" until it comes out calmly.

Most BDS students prepare for the viva by memorising answers. Examiners are not testing recall — they are testing whether you can reason, and whether you would be safe with a patient. Those need different preparation.

What the examiner is actually assessing

• Do you understand it, or have you memorised it?
• Can you apply it to a case you have not seen before?
• Do you know the limits of what you know?
• Would you be safe unsupervised?

The last two matter more than students assume. A candidate who says "I would refer this" at the right moment scores better than one who confidently attempts something beyond them.

How questions escalate

Vivas usually follow a ladder. A factual opener, then application, then a complication, then the edge of your knowledge.

Example: What is the composition of GIC? → Why would you choose it over composite here? → This patient has high caries risk and poor cooperation, now what? → What would change your mind?

You are supposed to reach the point where you do not know. That is the examiner finding your ceiling, not catching you out.

Answering well

• Answer the question asked. Not the adjacent one you revised.
• Structure out loud. "There are three main causes — I will take them in turn." It buys thinking time and sounds organised.
• Reason aloud on clinical questions. The examiner wants your thought process, not just the endpoint.
• Pause before answering. Two seconds of thought beats a fast wrong answer.
• Do not bluff. Examiners detect it immediately and will pursue it.

When you do not know

Say so cleanly, then show how you would find out: "I am not certain of the exact figure. What I do know is that it is used where moisture control is difficult, and I would check the manufacturer's instructions before use."

That answer scores. Silence and invention both do not.

A preparation method that works

• Practise out loud, with someone. Knowing it silently and saying it under pressure are different skills. This is the single highest-yield change.
• For every topic, prepare the ladder: definition, classification, clinical relevance, what you would do, when you would refer.
• Use real cases. Cases from your clinical postings stick far better than textbook lists, and they give you something concrete to cite.
• Prepare the obvious openers — your cases, your instruments, your materials. These come up almost every time.
• Practise the "I do not know" answer until it comes out calmly. You will need it.

On the day

Know your own cases cold — that is where most vivas start. Carry your logbook organised. If you misspeak, correct yourself immediately and move on; examiners respect a clean correction. And do not let one bad question follow you into the next.

A daily MCQ habit keeps recall sharp between now and then — see building a daily MCQ habit.