NBDE Restorative Dentistry 2

Question 1

Which dental material exhibits the highest coefficient of thermal expansion, most closely matching that of dentin?

Accepted Answer

Composite resin

Answer

Composite resin has a coefficient of thermal expansion closest to tooth structure among common restorative materials, though it is still higher than enamel and dentin.

Question 2

A Class II amalgam restoration is being placed. What is the primary purpose of the proximal box form?

Accepted Answer

To provide access and extension for the proximal surface

Answer

The proximal box of a Class II preparation provides access and extension to include the carious proximal surface and clear the contact area.

Question 3

When placing a composite resin restoration, incremental layering is recommended primarily to:

Accepted Answer

Reduce polymerization shrinkage stress

Answer

Incremental placement reduces the C-factor and allows each layer to partially relieve polymerization shrinkage stress before the next layer is added.

Question 4

Which type of dental cement has the highest compressive strength and is most commonly used for permanent cementation of cast metal restorations?

Accepted Answer

Zinc phosphate

Answer

Zinc phosphate cement has the highest compressive strength among traditional luting cements and has been used as the gold standard for permanent cast restoration cementation.

Question 5

A patient presents with a large carious lesion approaching the pulp. After caries removal, a thin layer of dentin remains. The BEST liner material to place is:

Accepted Answer

Calcium hydroxide

Answer

Calcium hydroxide is used as a direct or indirect pulp capping agent because it induces reparative dentin formation and has a high pH that is bactericidal.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Restorative Dentistry 2