Deck 2: Oral Environment and Patient Considerations

Question 1

Stress is the amount of force exerted from within an object and ______ is the amount of change that the force has produced.

A) compression
B) tension
C) strain
D) chemical bonding

Answer 1

strain

Question 2

The staining of resins and acrylics from repeated exposure to coffee, tea, and other dyed beverages is due to:

A) compressive forces
B) water sorption
C) tarnish
D) galvanism

Answer 2

water sorption

Question 3

Some dental materials may be therapeutic in small quantities or if in contact with tissues for a short period of time, but also may be irritating or toxic with longer or larger doses.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true, the second statement is false.
D) The first statement is false, the second statement is true.

Answer 3

Both statements are true.

Question 4

Excessive expansion of a restorative material may result in:

A) leakage of fluid and bacteria into the gaps
B) galvanism
C) corrosion
D) fracture of cusps

Question 5

Percolation:

A) helps seal the interface between tooth and restorative material
B) allows the ingress of bacteria and oral fluids and may lead to recurrent caries, staining, and pulpal irritation
C) is the rate at which heat flows through a material
D) is a form of chemical rather than mechanical retention

Question 6

Fatigue failure:

A) occurs as the result of a large, single-force application
B) occurs as the result of microscopic flaws that grow over time
C) is not a factor for restorative dental materials
D) is not dependent upon conditions in the oral cavity

Question 7

Which of the following restorative materials has a coefficient of thermal expansion and thermal conductivity closest to enamel?

A) Amalgam
B) Porcelain
C) Gold
D) Composite resin

Question 8

Which of the following has been suggested to delay formation of surface tarnish on dental amalgams?

A) Incremental addition
B) Polishing
C) Use of non-copper containing dental amalgam
D) Undercondensation

Question 9

Which of the following would not be an adverse effect of a material?

A) Toxicity
B) Hyposensitivity
C) Hypersensitivity
D) Postoperative sensitivity

Question 10

The technique of chemical bonding rather than mechanical means to produce retention requires ______ removal of tooth structure and produces a _______ retentive force between tooth and restoration.

A) more; stronger
B) more; weaker
C) less; stronger
D) less; weaker

Question 11

Which of the following materials has the highest ultimate compressive strength (lbs/in²)?

A) Amalgam
B) Porcelain
C) Composite resins
D) Acrylic

Question 12

Which of the following is the best thermal conductor?

A) Ceramic
B) Gold
C) Enamel
D) Dentin

Question 13

Which of the following dental restorative materials is particularly susceptible to corrosion?

A) Composite resin
B) Dental porcelain
C) Dental amalgam
D) Acrylic

Question 14

Normal masticatory forces on the occlusal surfaces of molar teeth can increase to as much as _________ pounds per square inch on a cusp tip.

A) 280
B) 1000
C) 10,000
D) 28,000

Question 15

_______________ refers to the intensity or strength of the color.

A) Hue
B) Value
C) Chroma
D) Opacity

Question 16

__________ force is applied when two surfaces slide against each other or in a twisting or rotating motion.

A) Compressive
B) Tensile
C) Shearing
D) Axial

Question 17

Which of the following statements is true for the property of wetting as related to dental materials?

A) The Teflon surface of cooking equipment has good wetting.
B) A thin film of dental cement is desirable to cement crowns.
C) A surface has high surface energy when liquids bead up on the surface.
D) Liquids generally spread better over low surface energy surfaces.

Question 18

Which of the following is considered to be the most reliable means of clinical assessment of composite and glass ionomer restorations?

A) Evaluation of radiographs
B) Tactile evaluation of the tooth surface
C) The patient history
D) Use of the air-water syringe

Question 19

The normal resting pH of saliva ranges from 6.2 to __, which is neutral.

A) 1
B) 6.6
C) 7
D) 14

Question 20

Which of the following is true of galvanism?

A) It is an electrical current transmitted between two similar metals.
B) It is observed in patients with composite resin but not silver amalgam restorations.
C) Galvanic stimulation will decrease with time as oxides form on the surface of the metal.
D) The salts of the saliva inhibit the movement of electrical current from one type of metal to another.

Question 21

Some materials give off heat when mixed. This is called a/an:

A) chemical reaction
B) thermal conductivity
C) coefficient of thermal expansion
D) exothermic reaction

Question 22

The thermal conductivity of composite resin:

A) is similar to tooth structure
B) is lower than tooth structure
C) is similar to metal restorations
D) does not conduct temperature

Question 23

Most modern dental materials are made to be moisture resistant.

Question 24

Normal pH of saliva is:

A) 4.2 to 5
B) 5.2 to 6
C) 6.2 to 7
D) 7.2 to 8

Question 25

The coefficient of thermal expansion is significant in dental materials because it:

A) measures the change in volume and length of a restoration
B) measures the change in oral temperature related to foods ingested
C) measures the amount of percolation of the restoration interface
D) measures the amount of stress and strain placed on the restoration

Question 26

Of the three types of forces, which is most concerned with the stretching of a material?

A) Tensile force
B) Compressive force
C) Shearing force

Question 27

When an object cannot resist force, ____________ occurs.

A) deformation
B) distortion
C) Both are correct.

Question 28

Match the items with the correct description below.
Thermal conductivity

A)Electrical current between two dissimilar metals
B)Discoloration due to oxidation of the metal's surface
C)Deterioration of the metal due to moisture and acid present in the oral
D)The rate at which heat flows through a material
E)Opening and closing of a gap between the restoration and the tooth surface

Question 29

The color range of a tooth is usually seen by the human eye as yellow or brown. This component is classified as:

A) chroma
B) hue
C) value

Question 30

Match the items with the correct description below.
Galvanism environment

A)Electrical current between two dissimilar metals
B)Discoloration due to oxidation of the metal's surface
C)Deterioration of the metal due to moisture and acid present in the oral
D)The rate at which heat flows through a material
E)Opening and closing of a gap between the restoration and the tooth surface

Question 31

Which of the following is NOT a good conductor of temperature?

A) Gold crown
B) Amalgam restoration
C) Composite resin restoration

Question 32

Adhesion is the method of ______ retention.

A) chemical
B) mechanical
C) dual

Question 33

The thicker or thinner a material is, is called its:

A) flowability
B) density
C) viscosity
D) thixotropic

Question 34

Contact between two dissimilar metals in the mouth may result in:

A) galvanic shock
B) metallic taste
C) electrical current
D) All of the above are possible.

Question 35

Match the items with the correct description below.
Tarnish

A)Electrical current between two dissimilar metals
B)Discoloration due to oxidation of the metal's surface
C)Deterioration of the metal due to moisture and acid present in the oral
D)The rate at which heat flows through a material
E)Opening and closing of a gap between the restoration and the tooth surface

Question 36

Fatigue failure occurs when:

A) microleakage produces recurrent caries and restoration failure
B) microscopic flaws occur, resulting in fracture of the restoration
C) excessive expansion and contraction result in voids at the interface
D) percolation of the restoration results in tooth sensitivity

Question 37

Match the items with the correct description below.
Corrosion

A)Electrical current between two dissimilar metals
B)Discoloration due to oxidation of the metal's surface
C)Deterioration of the metal due to moisture and acid present in the oral
D)The rate at which heat flows through a material
E)Opening and closing of a gap between the restoration and the tooth surface

Question 38

Match the items with the correct description below.
Percolation

A)Electrical current between two dissimilar metals
B)Discoloration due to oxidation of the metal's surface
C)Deterioration of the metal due to moisture and acid present in the oral
D)The rate at which heat flows through a material
E)Opening and closing of a gap between the restoration and the tooth surface

Question 39

Which of the following is not a concern regarding identification of dental materials in the mouth?

A) Therapeutic agents could erode some materials.
B) Scaling could damage the surfaces of some materials.
C) Both are concerns when materials are identified.

Question 40

Microleakage is caused by:

A) a poorly placed restoration
B) a fracture within a restoration
C) expansion and contraction of a restoration
D) All of the above could cause microleakage.

Question 41

List and describe the three components of color.

Question 42

List and describe the three basic types of force.