NBDE Part II 3

Question 1

Which of the following best describes the mechanism of action of fluoride in caries prevention?

Accepted Answer

It forms fluorapatite, which is more resistant to acid dissolution than hydroxyapatite

Answer

Fluoride substitutes for hydroxyl groups in hydroxyapatite to form fluorapatite, which has a lower critical pH and is significantly more resistant to acid dissolution.

Question 2

A 55-year-old edentulous patient needs complete dentures. Which jaw relation record is taken first during the construction sequence?

Accepted Answer

Vertical dimension of occlusion

Answer

Vertical dimension of occlusion (VDO) must be established before centric relation can be recorded, as the correct jaw separation is needed to make a reproducible record.

Question 3

Furcation involvement classified as Class II (Glickman) means:

Accepted Answer

The probe enters the furcation but does not pass through

Answer

Glickman Class II furcation involvement means the horizontal probe enters the furcation entrance but does not pass to the other side.

Question 4

When taking a periapical radiograph using paralleling technique, the primary benefit over bisecting angle is:

Accepted Answer

Reduced distortion and more accurate representation of tooth length

Answer

The paralleling technique places the film parallel to the tooth's long axis, minimizing geometric distortion and providing accurate tooth length and bone level readings.

Question 5

A patient on warfarin therapy requires a simple extraction. Their INR is 2.3. The correct management is:

Accepted Answer

Proceed with extraction using local hemostatic measures

Answer

An INR ≤3.5 is acceptable for simple dental extractions; local hemostatic measures (gelatin sponge, pressure) are sufficient without altering anticoagulant therapy.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Part II 3