Dental Dental Materials 2

Question 1

Which dental cement is considered most biocompatible with the pulp tissue?

Accepted Answer

Zinc oxide eugenol (ZOE) cement

Answer

Zinc oxide eugenol cement is highly biocompatible because eugenol has a sedative, obtundent effect on the pulp and the material has a near-neutral pH.

Question 2

What does polymerization shrinkage of composite resin result in clinically?

Accepted Answer

Microleakage and marginal gap formation

Answer

As composites shrink toward the light source during polymerization, gaps can form at the restoration margins, leading to microleakage and potential secondary caries.

Question 3

What is the primary advantage of polyvinyl siloxane (PVS) impression material over polysulfide?

Accepted Answer

Superior dimensional accuracy and stability

Answer

PVS impressions are highly dimensionally accurate and stable, allowing casts to be poured days after the impression is taken without significant distortion.

Question 4

Which type of dental porcelain is fused directly to a metal substructure in a PFM crown?

Accepted Answer

Feldspathic porcelain

Answer

Feldspathic porcelain is the traditional veneering porcelain used in PFM restorations because it bonds well to the metal oxide layer on the substructure.

Question 5

Increasing the water-to-powder ratio of a gypsum mix will have which effect on the set product?

Accepted Answer

Decreased strength and increased setting time

Answer

Excess water dilutes the reaction, slowing setting time and leaving more porosity in the set material, resulting in reduced compressive strength.

Dental Practice Test

Dental Practice Test

Dental Dental Materials 2