DANB Dental Materials & Laboratory Procedures

Question 1

Which dental material is commonly used for taking final impressions?

Accepted Answer

Polyvinyl siloxane

Answer

Polyvinyl siloxane (PVS) is a highly accurate elastomeric impression material commonly used for final impressions due to its excellent dimensional stability, tear strength, and ability to capture fine details. These properties make it ideal for fabricating precise crowns, bridges, and other indirect restorations. Its accuracy ensures a well-fitting restoration.

Question 2

What is the primary purpose of a dental liner?

Accepted Answer

To protect the pulp

Answer

A dental liner is a thin layer of material, often calcium hydroxide, applied to the deepest portion of a cavity preparation. Its primary purpose is to protect the dental pulp from chemical irritation, thermal changes, and bacterial invasion. This promotes pulpal health and aids in secondary dentin formation, preventing sensitivity and damage.

Question 3

Which material is typically used to create study models?

Accepted Answer

Dental plaster

Answer

Dental plaster, specifically Type II gypsum, is commonly used to create study models (diagnostic casts) because it is economical, easy to mix, and sets relatively quickly. While not as strong or abrasion-resistant as dental stone, it provides sufficient detail and strength for diagnostic, educational, and treatment planning purposes.

Question 4

What is the purpose of triturating dental amalgam?

Accepted Answer

To mix mercury with alloy powder

Answer

Trituration is the mechanical process of mixing the liquid mercury with the powdered alloy in a dental amalgam capsule. This process initiates the chemical reaction that forms the amalgam, creating a plastic mass that can be condensed into the cavity preparation. The material then hardens into a durable restoration.

Question 5

What is the ideal storage condition for alginate impression material before use?

Accepted Answer

Cool and dry

Answer

Alginate impression material is sensitive to moisture and temperature fluctuations, which can affect its shelf life and working properties. Storing it in a cool, dry environment, away from direct sunlight and humidity, helps prevent premature degradation. This ensures consistent setting times and accurate impressions when the material is used.

DANB General Chairside Assisting (GC) Test Practice Test

DANB General Chairside Assisting (GC) Test Practice Test

DANB Dental Materials & Laboratory Procedures