ADAT Dental Materials & Biomechanics

Question 1

Which property of dental composite resins describes the decrease in volume that occurs upon polymerization?

Accepted Answer

Answer

Polymerization shrinkage (1–4% by volume) occurs as monomer molecules form covalent polymer chains, creating stress at the restoration-tooth interface.

Question 2

What is the primary component of dental amalgam that gives it strength and dimensional stability?

Accepted Answer

Answer

The gamma-1 phase (Ag2Hg3) formed during amalgam setting provides the primary strength and hardness of the final restoration.

Question 3

Which impression material has the highest dimensional accuracy and is considered the gold standard for fixed prosthodontic impressions?

Accepted Answer

Answer

Polyvinyl siloxane (addition silicone) offers superior dimensional stability, accuracy, and can be poured multiple times, making it the gold standard for crown and bridge impressions.

Question 4

What is the compressive strength of human enamel, and why is this important for restorative material selection?

Accepted Answer

Answer

Enamel has a compressive strength of approximately 384 MPa, so restorative materials must have comparable strength to withstand masticatory loads without fracture.

Question 5

Glass ionomer cements (GIC) release which ion that provides an ongoing cariostatic effect?

Accepted Answer

Answer

Glass ionomer cements release fluoride ions continuously, providing a sustained cariostatic effect that helps prevent secondary caries around restorations.

Advanced Dental Admission Test (ADAT) Practice Test

Advanced Dental Admission Test (ADAT) Practice Test

ADAT Dental Materials & Biomechanics