Dental materials and radiology: paralleling technique: 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: paralleling technique

Sample item

Which advantage does the paralleling (long cone) technique have over the bisecting angle technique for periapical radiographs?

AUses a shorter source-to-film distanceBLess geometric distortion of tooth lengthCReduces dose by halfDNeeds no film holder

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

The answer and the reasoning

B. Less geometric distortion of tooth length

In the paralleling technique the film is parallel to the long axis of the tooth and the beam is perpendicular, giving accurate image dimensions. A film holder and a long source-to-film distance are required.

Option by option

A. Uses a shorter source-to-film distance
It uses a longer, not shorter, distance.
B. Less geometric distortion of tooth length (correct)
Correct. Parallel placement preserves tooth dimensions.
C. Reduces dose by half
The dose is not halved by the technique.
D. Needs no film holder
A film holder is needed for this technique.

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, Less geometric distortion of tooth length. In the paralleling technique the film is parallel to the long axis of the tooth and the beam is perpendicular, giving accurate image dimensions.

Why is "Uses a shorter source-to-film distance" not the answer?

It uses a longer, not shorter, distance.

Why is "Reduces dose by half" not the answer?

The dose is not halved by the technique.

Why is "Needs no film holder" not the answer?

A film holder is needed for this technique.

What concept does this question test?

It tests Dental materials and radiology: paralleling technique in Dentistry. A film holder and a long source-to-film distance are required.

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: paralleling technique?

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.