Dental materials and radiology basics: bonding glass ceramic: 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: bonding glass ceramic

Sample item

A lithium disilicate glass-ceramic veneer is to be bonded with resin cement. Which treatment of its fitting surface gives both micromechanical retention and chemical bonding?

ADiamond polishing followed by a dentine primerBPhosphoric acid etching followed by a plain bonding resinCAlumina air abrasion followed by an MDP primerDHydrofluoric acid etching, then a silane coupling agent

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

The answer and the reasoning

D. Hydrofluoric acid etching, then a silane coupling agent

Hydrofluoric acid dissolves the glassy phase to roughen the ceramic, and silane forms siloxane bonds with the silica and methacrylate bonds with the resin cement. Alumina abrasion with an MDP primer is the protocol for zirconia and other non-silica ceramics, not for lithium disilicate.

Option by option

A. Diamond polishing followed by a dentine primer
A polished surface offers no retention and a dentine primer does not bond to ceramic.
B. Phosphoric acid etching followed by a plain bonding resin
Phosphoric acid does not etch glass ceramic, so little retention would result.
C. Alumina air abrasion followed by an MDP primer
Air abrasion with MDP primer is used for zirconia, which lacks a glassy silica phase.
D. Hydrofluoric acid etching, then a silane coupling agent (correct)
Correct. HF etching creates retention and silane chemically links ceramic to resin.

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 D, Hydrofluoric acid etching, then a silane coupling agent. Hydrofluoric acid dissolves the glassy phase to roughen the ceramic, and silane forms siloxane bonds with the silica and methacrylate bonds with the resin cement.

Why is "Diamond polishing followed by a dentine primer" not the answer?

A polished surface offers no retention and a dentine primer does not bond to ceramic.

Why is "Phosphoric acid etching followed by a plain bonding resin" not the answer?

Phosphoric acid does not etch glass ceramic, so little retention would result.

Why is "Alumina air abrasion followed by an MDP primer" not the answer?

Air abrasion with MDP primer is used for zirconia, which lacks a glassy silica phase.

What concept does this question test?

It tests Dental materials and radiology basics: bonding glass ceramic in Dentistry. Alumina abrasion with an MDP primer is the protocol for zirconia and other non-silica ceramics, not for lithium disilicate.

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: bonding glass ceramic?

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.