NDAEB Dental Materials and Equipment

Question 1

Dental amalgam is formed when mercury reacts with which alloy?

Accepted Answer

Silver-tin alloy

Answer

Dental amalgam is created when liquid mercury is combined with a silver-tin alloy powder, forming a stable, hardened restorative material.

Question 2

Which type of composite resin is BEST suited for high-stress posterior restorations?

Accepted Answer

Packable (condensable) composite

Answer

Packable composites have the highest filler loading and greatest wear resistance, making them the preferred choice for posterior restorations under occlusal stress.

Question 3

Glass ionomer cement is unique among restorative materials because it continuously releases which beneficial ion?

Accepted Answer

Fluoride

Answer

Glass ionomer cement releases fluoride ions over time, providing a cariostatic effect that helps prevent secondary decay around restorations.

Question 4

What does 'working time' mean when referring to dental restorative materials?

Accepted Answer

Time from start of mixing during which the material can be manipulated

Answer

Working time is the period beginning at the start of mixing during which a dental material can be properly manipulated, adapted, and placed before it begins to set.

Question 5

What is the primary purpose of placing a base material in a deep tooth preparation before restoring?

Accepted Answer

To provide pulpal protection from thermal and chemical stimulation

Answer

A base is placed in deep preparations to insulate the pulp from thermal and chemical irritation caused by restorative materials and temperature changes.

(NDAEB) National Dental Assisting Examination Board Practice Test

(NDAEB) National Dental Assisting Examination Board Practice Test

NDAEB Dental Materials and Equipment