INBDE Restorative Dentistry and Dental Materials 2

Question 1

What is the primary purpose of acid etching enamel before bonding?

Accepted Answer

Create microporosities for micromechanical retention

Answer

Phosphoric acid (30–40%) selectively dissolves enamel hydroxyapatite, creating microporosities that allow resin tags to form and provide micromechanical retention.

Question 2

The working time of zinc phosphate cement can be extended by:

Accepted Answer

Spatulating on a cold, thick glass slab

Answer

Cooling the glass slab to 18°C slows the exothermic setting reaction, extending working time; large slab area also dissipates heat.

Question 3

Which impression material provides the highest dimensional accuracy and detail reproduction?

Accepted Answer

Polyvinyl siloxane (PVS/addition silicone)

Answer

Polyvinyl siloxane (addition silicone) provides the highest dimensional accuracy, excellent detail reproduction, and good dimensional stability over time.

Question 4

A cusp that is fully included within the outer cusp ridges of the opposing arch during maximum intercuspation is classified as a:

Accepted Answer

Supporting cusp (centric holding cusp)

Answer

Supporting (centric holding) cusps — maxillary palatal and mandibular buccal — contact the opposing tooth in centric occlusion, maintaining vertical dimension.

Question 5

Secondary caries (recurrent caries) occurs most frequently at which location of an existing restoration?

Accepted Answer

Proximal gingival margin

Answer

The proximal gingival margin is the most common site for recurrent caries due to difficulty in cleaning, plaque accumulation, and microleakage at the cervical margin.

INBDE - Integrated National Board Dental Exam Practice Test

INBDE - Integrated National Board Dental Exam Practice Test

INBDE Restorative Dentistry and Dental Materials 2