NBDE Prosthodontics and Operative Dentistry 5

Question 1

Which type of pontic design is most hygienic for a fixed partial denture in the posterior region?

Accepted Answer

Sanitary (hygienic) pontic

Answer

The sanitary (hygienic) pontic does not contact the residual ridge at all, making it the easiest to clean and most tissue-friendly design.

Question 2

During the preparation of an MOD cavity for a Class II amalgam restoration, the proximal box should be extended faciolingually until:

Accepted Answer

The margins are in a self-cleansing area just clear of the adjacent tooth

Answer

Proximal margins must extend just beyond the contact area to a self-cleansing zone where instruments can finish margins and caries risk is reduced.

Question 3

The primary advantage of using a facebow transfer when mounting casts for complete denture fabrication is that it:

Accepted Answer

Relates the maxillary cast to the hinge axis of the articulator mimicking the patient's TMJ

Answer

A facebow transfer records the spatial relationship of the maxilla to the transverse hinge axis so the casts open and close on the articulator as they would in the patient.

Question 4

Which cavity preparation principle was modified by GV Black's successors to adopt a more conservative 'extension for prevention' approach?

Accepted Answer

Outline form (extension for prevention)

Answer

GV Black's 'extension for prevention' placed margins in self-cleansing areas even in caries-free zones; modern adhesive dentistry restricts preparation to only carious or defective structure.

Question 5

A patient with xerostomia and multiple cervical carious lesions is best restored with:

Accepted Answer

Resin-modified glass ionomer cement

Answer

Resin-modified glass ionomer releases fluoride, bonds chemically to dentin, and tolerates mild moisture — ideal for xerostomic patients with high caries risk.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Prosthodontics and Operative Dentistry 5