NBDE Prosthodontics and Operative Dentistry 2

Question 1

Which finish line preparation design provides the best esthetic result for an all-ceramic crown?

Accepted Answer

Deep chamfer or shoulder

Answer

A deep chamfer or shoulder finish line provides adequate bulk of ceramic material at the margin for optimal esthetics and strength.

Question 2

The Kennedy Class II modification 1 removable partial denture indicates:

Accepted Answer

Unilateral posterior edentulous area with one anterior modification space

Answer

Kennedy Class II is a unilateral posterior edentulous area, and modification 1 indicates one additional edentulous area elsewhere in the arch.

Question 3

The resistance form in cavity preparation primarily prevents:

Accepted Answer

Fracture of the tooth or restoration under occlusal loading

Answer

Resistance form consists of features that prevent fracture of both the tooth structure and the restorative material under occlusal forces.

Question 4

When fabricating a complete denture, the vertical dimension of occlusion (VDO) differs from the vertical dimension of rest (VDR) by approximately:

Accepted Answer

1-2 mm (freeway space)

Answer

The freeway space (interocclusal rest space) is typically 2-4 mm, so VDO is approximately 2-4 mm less than VDR.

Question 5

A cast metal post and core is contraindicated when:

Accepted Answer

The remaining root structure is less than 1 mm thick at any point

Answer

Roots with less than 1 mm of dentin thickness at any point risk perforation or fracture during post preparation or cementation.

NBDE - National Board Dental Examination Practice Test