Caries and periodontal disease: pathogenesis of fluorosis: 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: pathogenesis of fluorosis

Sample item

Children in an endemic area have mottled, pitted enamel. At the cellular level, what is the main mechanism?

AAutoimmune destruction of odontoblastsBFluoride disturbs ameloblast function and matrix protein removal, causing hypomineralisationCVitamin A deficiency causing keratinisation of enamel organDAcid dissolution of erupted enamel by plaque

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

The answer and the reasoning

B. Fluoride disturbs ameloblast function and matrix protein removal, causing hypomineralisation

Excess fluoride during enamel formation interferes with ameloblast activity and removal of enamel matrix proteins, leaving subsurface porosity and hypomineralised enamel. Only teeth developing during exposure are affected, which is why the effect depends on age at exposure.

Option by option

A. Autoimmune destruction of odontoblasts
Odontoblasts are not the target in fluorosis.
B. Fluoride disturbs ameloblast function and matrix protein removal, causing hypomineralisation (correct)
Correct. Developing ameloblasts and matrix maturation are disrupted.
C. Vitamin A deficiency causing keratinisation of enamel organ
Vitamin A deficiency can cause enamel hypoplasia, but this is not the fluorosis mechanism.
D. Acid dissolution of erupted enamel by plaque
This describes caries, which is not mottling.

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 B, Fluoride disturbs ameloblast function and matrix protein removal, causing hypomineralisation. Excess fluoride during enamel formation interferes with ameloblast activity and removal of enamel matrix proteins, leaving subsurface porosity and hypomineralised enamel.

Why is "Autoimmune destruction of odontoblasts" not the answer?

Odontoblasts are not the target in fluorosis.

Why is "Vitamin A deficiency causing keratinisation of enamel organ" not the answer?

Vitamin A deficiency can cause enamel hypoplasia, but this is not the fluorosis mechanism.

Why is "Acid dissolution of erupted enamel by plaque" not the answer?

This describes caries, which is not mottling.

What concept does this question test?

It tests Caries and periodontal disease: pathogenesis of fluorosis in Dentistry. Only teeth developing during exposure are affected, which is why the effect depends on age at exposure.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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: pathogenesis of fluorosis?

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.