Caries and periodontal disease: caries requirements: practice question

A Dentistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Dentistry · Caries and periodontal disease: caries requirements

Sample item

Which combination of factors is required for dental caries to develop?

AFluoride deficiency, vitamin D deficiency and bacteria aloneBFermentable carbohydrate and time without bacteriaCSusceptible tooth, cariogenic bacteria, fermentable carbohydrate and timeDSusceptible tooth, bacteria, dietary fat and time

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Susceptible tooth, cariogenic bacteria, fermentable carbohydrate and time

The classic Keyes model, with time added, needs a susceptible host tooth, cariogenic plaque bacteria and fermentable carbohydrate over sufficient time. Without bacteria, sugar alone cannot cause caries.

Option by option

A. Fluoride deficiency, vitamin D deficiency and bacteria alone
Vitamin D lack may affect tooth formation but does not alone cause caries.
B. Fermentable carbohydrate and time without bacteria
Acid production requires bacteria.
C. Susceptible tooth, cariogenic bacteria, fermentable carbohydrate and time (correct)
Correct. All four must interact.
D. Susceptible tooth, bacteria, dietary fat and time
Dietary fat is not cariogenic.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Dentistry question

What is the answer to this Dentistry question?

The best answer is C, Susceptible tooth, cariogenic bacteria, fermentable carbohydrate and time. The classic Keyes model, with time added, needs a susceptible host tooth, cariogenic plaque bacteria and fermentable carbohydrate over sufficient time.

Why is "Fluoride deficiency, vitamin D deficiency and bacteria alone" not the answer?

Vitamin D lack may affect tooth formation but does not alone cause caries.

Why is "Fermentable carbohydrate and time without bacteria" not the answer?

Acid production requires bacteria.

Why is "Susceptible tooth, bacteria, dietary fat and time" not the answer?

Dietary fat is not cariogenic.

What concept does this question test?

It tests Caries and periodontal disease: caries requirements in Dentistry. Without bacteria, sugar alone cannot cause caries.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Caries and periodontal disease: caries requirements?

Learn the dental formula, eruption ages and tooth structure once, as tables. Then use the flashcards and the other Dentistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.