Dental Dental Materials

Question 1

Which type of dental material is classified as an irreversible hydrocolloid impression material?

Accepted Answer

Alginate

Answer

Alginate is an irreversible hydrocolloid because its gelation is a chemical reaction that cannot be reversed by heating.

Question 2

What is the primary purpose of a cavity liner placed in a deep preparation?

Accepted Answer

To provide pulp protection from chemical and thermal irritation

Answer

A cavity liner is placed over the pulp to protect it from the chemical and thermal stimuli that restorative materials may transmit.

Question 3

Which gypsum product has the highest compressive strength and is used for dies?

Accepted Answer

Die stone (Type IV)

Answer

Type IV die stone (high-strength stone) has the highest compressive strength due to its low water-to-powder ratio, making it ideal for dies.

Question 4

What is the setting reaction of zinc phosphate cement?

Accepted Answer

Acid-base reaction between zinc oxide and phosphoric acid

Answer

Zinc phosphate cement sets via an acid-base reaction where phosphoric acid reacts with zinc oxide powder to form zinc phosphate salt.

Question 5

Which of the following composite filler types provides the best combination of strength and polishability?

Accepted Answer

Hybrid composite

Answer

Hybrid composites combine large and small filler particles, offering superior strength compared to microfills and better polishability than macrofills.

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Dental Practice Test

Dental Dental Materials