Dental materials and radiology basics: internal bleaching: 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 · Dental materials and radiology basics: internal bleaching

Sample item

Two years after walking bleach of a root-filled incisor with hot 30 percent hydrogen peroxide, a radiograph shows resorption at the cervical area. Which step prevents this complication?

APlacing a cervical barrier over the gutta-percha and avoiding heatBEtching the dentine before bleachingCLeaving the canal unfilled to drainDUsing a higher peroxide concentration with heat

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

The answer and the reasoning

A. Placing a cervical barrier over the gutta-percha and avoiding heat

Peroxide diffuses through dentinal tubules to the periodontal ligament and triggers cervical resorption, worse with heat. A glass ionomer barrier and milder agents reduce the risk.

Option by option

A. Placing a cervical barrier over the gutta-percha and avoiding heat (correct)
Correct. A barrier and no heat limit the diffusion of peroxide.
B. Etching the dentine before bleaching
Etching opens the tubules and increases diffusion.
C. Leaving the canal unfilled to drain
An unfilled canal risks reinfection and does not help.
D. Using a higher peroxide concentration with heat
Stronger peroxide and heat increase resorption.

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 A, Placing a cervical barrier over the gutta-percha and avoiding heat. Peroxide diffuses through dentinal tubules to the periodontal ligament and triggers cervical resorption, worse with heat.

Why is "Etching the dentine before bleaching" not the answer?

Etching opens the tubules and increases diffusion.

Why is "Leaving the canal unfilled to drain" not the answer?

An unfilled canal risks reinfection and does not help.

Why is "Using a higher peroxide concentration with heat" not the answer?

Stronger peroxide and heat increase resorption.

What concept does this question test?

It tests Dental materials and radiology basics: internal bleaching in Dentistry. A glass ionomer barrier and milder agents reduce the risk.

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 Dental materials and radiology basics: internal bleaching?

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.