Question 1

Which of the following statements is true of the tensile and compressive strengths of a material?

Accepted Answer

A)  They may be significantly different. 
B)  Brittle materials have small differences in tensile and compressive strength. 
C)  Brittle materials are stronger in tension than in compression. 
D)  A, B, and C are true. 
E)  A and C are true. 
A)  They may be significantly different. 
B)  Brittle materials have small differences in tensile and compressive strength. 
C)  Brittle materials are stronger in tension than in compression. 
D)  A, B, and C are true. 
E)  A and C are true. A

Question 2

Compare and contrast the terms absorption and adsorption.

Accepted Answer

Absorption refers to the uptake of liquid by the bulk solid.For example,the equilibrium absorption of water by acrylic polymers is in the range of 2%.Adsorption indicates concentration of molecules at the surface of a solid or liquid.

Question 3

Expansion and contraction rates between dental materials and tooth structure caused by temperature change vary.Gaps at the margins allow fluids to enter the space.This is known as:

Accepted Answer

A)  coefficient of thermal expansion. 
B)  thermal conductivity. 
C)  dimensional change. 
D)  percolation. 
A)  coefficient of thermal expansion. 
B)  thermal conductivity. 
C)  dimensional change. 
D)  percolation. D

Question 4

A metallic taste in the mouth may be a result of:

Accepted Answer

A)  galvanism. 
B)  corrosion. 
C)  contamination. 
D)  percolation. 
A)  galvanism. 
B)  corrosion. 
C)  contamination. 
D)  percolation.

Question 5

Which of the following statements is true of the measure of Knoop hardness?

Accepted Answer

A)  Hardness is directly related to yield strength and wear resistance. 
B)  It is obtained by measurement of the short diagonal of an indentation from a diamond indenter. 
C)  The larger the indentation, the smaller the value. 
D)  Enamel has a lower Knoop hardness value than dentin and cementum. 
A)  Hardness is directly related to yield strength and wear resistance. 
B)  It is obtained by measurement of the short diagonal of an indentation from a diamond indenter. 
C)  The larger the indentation, the smaller the value. 
D)  Enamel has a lower Knoop hardness value than dentin and cementum.

Question 6

Analysis of the strain-time curve indicates that the _____ the time and the _____ force applied to the impression material,the lower the permanent strain and the more accurate the impression.

Accepted Answer

A)  shorter; less 
B)  longer; less 
C)  shorter; more 
D)  longer; more 
A)  shorter; less 
B)  longer; less 
C)  shorter; more 
D)  longer; more

Question 7

Cavity varnishes and liners are ineffective as thermal insulators because they:

Accepted Answer

A)  have high thermal conductivity. 
B)  have a high coefficient of thermal expansion. 
C)  have a low coefficient of thermal expansion. 
D)  are used in thin layers. 
A)  have high thermal conductivity. 
B)  have a high coefficient of thermal expansion. 
C)  have a low coefficient of thermal expansion. 
D)  are used in thin layers.

Question 8

Which of the following is not a form of stress?

Accepted Answer

A)  Compressive 
B)  Flexure 
C)  Strain 
D)  Shear 
A)  Compressive 
B)  Flexure 
C)  Strain 
D)  Shear

Question 9

For a given force,the _____ the area over which it is applied,the _____ the value of the stress.

Accepted Answer

A)  smaller; smaller 
B)  smaller; larger 
C)  larger; larger 
D)  A and C 
E)  B and C 
A)  smaller; smaller 
B)  smaller; larger 
C)  larger; larger 
D)  A and C 
E)  B and C

Question 10

_____ occurs as the result of a discrepancy between the linear thermal coefficient of expansion between teeth and the restorative material if there is no bonding.

Accepted Answer

A)  Stress 
B)  Strain 
C)  Elastic modulus 
D)  Percolation 
E)  Yield strength 
A)  Stress 
B)  Strain 
C)  Elastic modulus 
D)  Percolation 
E)  Yield strength

Question 11

Which of the following is an electrical property of interest in the mouth?

Accepted Answer

A)  Coefficient of thermal expansion 
B)  Ductility 
C)  Elastic modulus 
D)  Galvanism 
E)  Percolation 
A)  Coefficient of thermal expansion 
B)  Ductility 
C)  Elastic modulus 
D)  Galvanism 
E)  Percolation

Question 12

If a liquid presents a contact angle of wettability greater than 90°,the material is said to be:

Accepted Answer

A)  thixotropic. 
B)  hydrophilic. 
C)  hydrophobic. 
D)  viscous. 
A)  thixotropic. 
B)  hydrophilic. 
C)  hydrophobic. 
D)  viscous.

Question 13

Percolation is thought to decrease with time following insertion of which of the following dental restorative materials?

Accepted Answer

A)  Filled resin composite 
B)  Unfilled acrylic resin 
C)  Cast gold 
D)  Dental amalgam 
E)  Ceramic 
A)  Filled resin composite 
B)  Unfilled acrylic resin 
C)  Cast gold 
D)  Dental amalgam 
E)  Ceramic

Question 14

Corrosion is the result of:

Accepted Answer

A)  contact of two dissimilar metals in the mouth. 
B)  poor oral hygiene around restorations. 
C)  acidic food and drink. 
D)  A and C only. 
A)  contact of two dissimilar metals in the mouth. 
B)  poor oral hygiene around restorations. 
C)  acidic food and drink. 
D)  A and C only.

Question 15

Dimensional change usually is expressed as a percentage of:

Accepted Answer

A)  the compressive strength. 
B)  the shear strength. 
C)  the tensile strength. 
D)  an original length or volume. 
E)  the final length or volume. 
A)  the compressive strength. 
B)  the shear strength. 
C)  the tensile strength. 
D)  an original length or volume. 
E)  the final length or volume.

Question 16

The hardness of a dental material is reported in:

Accepted Answer

A)  Knoop hardness. 
B)  nano-indentation. 
C)  diamond indenter. 
D)  dynamic properties. 
A)  Knoop hardness. 
B)  nano-indentation. 
C)  diamond indenter. 
D)  dynamic properties.

Question 17

Deformation of a material becomes permanent when the material reaches its:

Accepted Answer

A)  elastic modulus. 
B)  stress-strain curve. 
C)  ultimate strength. 
D)  yield strength. 
A)  elastic modulus. 
B)  stress-strain curve. 
C)  ultimate strength. 
D)  yield strength.

Question 18

The change in the length or deformation of a material when subjected to force is:

Accepted Answer

A)  flexure. 
B)  strain. 
C)  shear. 
D)  tensile. 
A)  flexure. 
B)  strain. 
C)  shear. 
D)  tensile.

Question 19

The greatest biting forces are on:

Accepted Answer

A)  molars. 
B)  bicuspids. 
C)  cuspids. 
D)  incisors. 
A)  molars. 
B)  bicuspids. 
C)  cuspids. 
D)  incisors.

Question 20

Patients with dentures can apply about ____% of the force of those with normal dentition.

Accepted Answer

A)  10 
B)  19 
C)  50 
D)  90 
E)  150 
A)  10 
B)  19 
C)  50 
D)  90 
E)  150

Which of the following statements is true of the tensile and compressive strengths of a material?

Compare and contrast the terms absorption and adsorption.

Expansion and contraction rates between dental materials and tooth structure caused by temperature change vary.Gaps at the margins allow fluids to enter the space.This is known as:

A metallic taste in the mouth may be a result of:

Which of the following statements is true of the measure of Knoop hardness?

Analysis of the strain-time curve indicates that the _ the time and the _ force applied to the impression material,the lower the permanent strain and the more accurate the impression.

Cavity varnishes and liners are ineffective as thermal insulators because they:

Which of the following is not a form of stress?

For a given force,the _ the area over which it is applied,the _ the value of the stress.

_____ occurs as the result of a discrepancy between the linear thermal coefficient of expansion between teeth and the restorative material if there is no bonding.

Which of the following is an electrical property of interest in the mouth?

If a liquid presents a contact angle of wettability greater than 90°,the material is said to be:

Percolation is thought to decrease with time following insertion of which of the following dental restorative materials?

Corrosion is the result of:

Dimensional change usually is expressed as a percentage of:

The hardness of a dental material is reported in:

Deformation of a material becomes permanent when the material reaches its:

The change in the length or deformation of a material when subjected to force is:

The greatest biting forces are on:

Patients with dentures can apply about ____% of the force of those with normal dentition.

Introduction to Restorative Dental Materials

Preventive Dental Materials

Direct Esthetic Restorative Materials

Dental Amalgam

Finishing, polishing, and Cleansing Materials

Cements

Impression Materials

Model and Die Materials

Waxes

Casting Alloys, wrought Alloys, and Solders

Casting and Soldering

Polymers in Prosthodontics

Dental Ceramics

Dental Implants

Filters

Exam 2: Properties of Materials

Which of the following statements is true of the tensile and compressive strengths of a material?

Compare and contrast the terms absorption and adsorption.

Expansion and contraction rates between dental materials and tooth structure caused by temperature change vary.Gaps at the margins allow fluids to enter the space.This is known as:

A metallic taste in the mouth may be a result of:

Which of the following statements is true of the measure of Knoop hardness?

Analysis of the strain-time curve indicates that the _____ the time and the _____ force applied to the impression material,the lower the permanent strain and the more accurate the impression.

Cavity varnishes and liners are ineffective as thermal insulators because they:

Which of the following is not a form of stress?

For a given force,the _____ the area over which it is applied,the _____ the value of the stress.

_____ occurs as the result of a discrepancy between the linear thermal coefficient of expansion between teeth and the restorative material if there is no bonding.

Which of the following is an electrical property of interest in the mouth?

If a liquid presents a contact angle of wettability greater than 90°,the material is said to be:

Percolation is thought to decrease with time following insertion of which of the following dental restorative materials?

Corrosion is the result of:

Dimensional change usually is expressed as a percentage of:

The hardness of a dental material is reported in:

Deformation of a material becomes permanent when the material reaches its:

The change in the length or deformation of a material when subjected to force is:

The greatest biting forces are on:

Patients with dentures can apply about ____% of the force of those with normal dentition.

Introduction to Restorative Dental Materials

Preventive Dental Materials

Direct Esthetic Restorative Materials

Dental Amalgam

Finishing, polishing, and Cleansing Materials

Cements

Impression Materials

Model and Die Materials

Waxes

Casting Alloys, wrought Alloys, and Solders

Casting and Soldering

Polymers in Prosthodontics

Dental Ceramics

Dental Implants

Filters

Analysis of the strain-time curve indicates that the _ the time and the _ force applied to the impression material,the lower the permanent strain and the more accurate the impression.

For a given force,the _ the area over which it is applied,the _ the value of the stress.