Chapter 1, 2, and 4

Question 1

the act of sticking two things together. In dentistry, it is used to describe the bonding or cementation process. Chemical adhesion occurs when atoms or molecules of dissimilar substances bond together and differs from cohesion in which attraction among atoms and molecules of similar materials holds them together

Answer 1

Adhesion

Question 2

An unintended, unexpected, and harmful or unwelcome response of an individual to dental treatment or biomaterial

Answer 2

adverse response

Question 3

materials used to fabricate and maintain restorations, directly or indirectly

Answer 3

auxiliary materials

Question 4

the property of a material that allows it not to impede or adversely affect living tissue

Answer 4

biocompatible

Question 5

a complex community of oral microorganisms living on surfaces within the mouth. When these colonies are found on teeth or restorations, they are commonly called dental plaque

Answer 5

biofilm

Question 6

to connect or fasten; to bind

Answer 6

bonding

Question 7

the intensity or strength of a color (e.g., a bold yellow has more chroma than a pastel yellow)

Answer 7

chroma

Question 8

coefficient of thermal expansion

Answer 8

the measurement of change in volume or length in relationship to change in temperature

Question 9

compressive force

Answer 9

force applied to compress an object

Question 10

deterioration of a metal caused by a CHEMICAL attack or electrochemical reaction with dissimilar metals in presence of a solution containing electrolytes (such as saliva)

Answer 10

corrosion

Question 11

dimensional change

Answer 11

a change in the size of matter. For dental materials, this usually manifests as expansion

Question 12

exothemric reaction

Answer 12

the production of heat resulting from the reaction of the components of some materials when they are mixed

Question 13

a fractures resulting from repeated stresses that produce microscopic flaws that grow

Answer 13

fatigue failure

Question 14

film thickness

Answer 14

the minimal obtainable thickness of a layer of material. It is particularly important in the context of dental cements

Question 15

flexural stress

Answer 15

bending caused by a combination of tension and compression

Question 16

fracture toughness

Answer 16

a measure of the energy needed to fracture a material

Question 17

galvanism

Answer 17

an electrical current transmitted between two dissimilar metals in a solution of electrolytes

Question 18

hue

Answer 18

the color of a tooth or restoration. It may include a mixture of colors, such as yellow-brown

Question 19

insulators

Answer 19

materials having low thermal conductivity

Question 20

interface

Answer 20

the surface between the walls of preparation and the restoration or between two dental materials

Question 21

microleakage

Answer 21

leakage of fluid and bacteria caused by microscopic gaps that occur at the interface of the tooth and the restoration margins

Question 22

opaque

Answer 22

optical property in which light is completely absorbed by an object

Question 23

percolation

Answer 23

movement of fluid in the microscopic gap of a restoration margin as a result of differences in the expansion and contraction rates of the tooth and the restoration with temperature changes associated with ingestion of cold or hot fluids or foods

Question 24

Resilience

Answer 24

a measure of the energy needed to permanently deform a material

Question 25

restorative materials

Answer 25

materials used to reconstruct tooth structure

Question 26

retention

Answer 26

material’s ability to maintain its position without displacement under stress

Question 27

shearing force

Answer 27

force applied when to surfaces slide against eachother

Question 28

solubility

Answer 28

susceptible to being dissolved

Question 29

strain

Answer 29

distortion or deformation that occurs when an object cannot resist a force

Question 30

the internal force, which resists the applied force

Answer 30

stress

Question 31

the electrical charge that attracts atoms to a surface

Answer 31

surface energy

Question 32

discoloration resulting from oxidation of a thin layer of a metal at its surface. It is not as destructive as corrosion

Answer 32

tarnish

Question 33

tensile force

Answer 33

force applied in opposite directions to stretch an object

Question 34

therapeutic materials

Answer 34

materials used to treat disease

Question 35

Torsion or torque

Answer 35

a twisting force that combines tensile and compressive forces

Question 36

optical property in which varying degrees of light pass through or are absorbed by an object

Answer 36

transluceny

Question 37

optical property in which light passes directly through an object

Answer 37

transparent

Question 38

ultimate strength

Answer 38

the maximum amount of stress a material can withstand without breaking

Question 39

value

Answer 39

how light or dark a color is. A low value indicates a darker color and a high value indicates a brighter color

Question 40

viscosity

Answer 40

the ability of a liquid material to resist flow, e.g. ketchup is more viscous than water

Question 41

vitality

Answer 41

a life-like quality

Question 42

water sorption

Answer 42

the ability to absorb moisture

Question 44

wetting

Answer 44

the ability of a liquid to wet or intimately contact a solid surface. Water beading on a waxed car is an example of poor wetting

Question 45

Scientific evidence replaces clinical expertise in evidence-based dentistry true or false?

Answer 45

False

Question 46

An allied oral health practitioner must know the selection of a particular material in a given situation and how to manipulate it. It is solely the dentist’s responsibility to educate the patient on materials used in his or her treatment plan.

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 46

c. The first statement is true, the second statement is false

Question 47

The dental therapist is an auxiliary who provides preventive and restorative care under the supervision of a dentist. The scope of what this auxiliary can perform is regulated by the ADA.

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 47

c. The first statement is true; the second statement is false.

Rationale:

Dental therapists are dental auxiliaries who provide preventive and restorative care to children and adults, primarily in settings that serve low-income, uninsured, or underserved populations. The scope of practice for dental auxiliaries is determined by individual state regulations, not the ADA.

Question 48

According to the U.S. Food and Drug Administration (FDA) Medical Device Amendments of 1976, dental materials such as bone grafts fall into which category?

a. Class I
b. Class II
c. Class III
d. Class IV

Answer 48

c. Class III

Rationale:

Class III medical devices such as bone grafts and endosseous implants are the most regulated medical devices because they support or sustain human life. These devices must have scientific reviews in order to gain FDA approval. Class I devices have the lowest safety risk and include materials such as gloves and toothbrushes. Class II devices must meet specific performance standards and include such materials as amalgam and other restorative materials.

Question 49

Dental materials manufacturers voluntarily submit their products to which of the following for stringent testing and verification of product claims?

a. FDA
b. American National Standards Institute (ANIS)
c. International Standards Organization (ISO)
d. ADA

Answer 49

d. ADA

Rationale:

Submission of a product to the ADA’s Council on Scientific Affairs to receive the Seal of Approval is solely on a voluntary basis. The Seal of Approval on a product signifies it has met stringent standards, lending confidence to consumer purchasing. The FDA regulation of all medical (dental) devices/products is mandatory. ANIS exists to enhance global competitiveness of U.S. business, ensuring consumer safety and protection of the environment. ISO sets international product standards.

Question 50

Humans have suffered from dental disease for millennia. However, the first evidence of restorative dentistry appeared when?

a. 1.7 million years ago
b. 2500 BC
c. 600 BC
d. The 18th century

Answer 50

c. 600 BC

Rationale:

The first evidence of restorative dentistry appeared around 600-300 BC using gold, natural teeth, and cadaver teeth. Dental disease has been noted as far back as the caveman, and evidence of toothpick use has been dated back 1.7 million years ago. Mummies dating from 2500 BC show evidence of abscesses and periodontal disease but not restorations. By the 1700s, dental restorations had been around for almost 2000 years.

Question 51

Which of the following is not eligible for the American Dental Association (ADA) Seal of Acceptance?

a. Dental amalgam
b. Toothpaste
c. Mouth rinses
d. Dental floss

Answer 51

a. Dental amalgam

Rationale:

In 2005, the ADA phased out its Seal of Acceptance for professional dental products and now focuses solely on consumer products. Dental amalgam is only used as a restorative material by dental professionals and is not available as a consumer product.

Question 52

Once used as a paste, silver has been used as a restorative material since the 7th century.

a. True
b. False

Answer 52

a. True

Question 53

Which entity evaluates new dental materials before they can be used in the dental office or sold in the United States?

a. ADA
b. FDA
c. ISO
d. FDI World Dental Federation

Answer 53

b. FDA

Rationale:

Dental materials and products, including those sold over the counter, are considered medical devices and are therefore controlled and regulated by the FDA Center for Devices and Radiological Health. Submission of a product to the ADA’s Council on Scientific Affairs to receive the Seal of Approval is solely on a voluntary basis. The ISO and FDI represent the standards used to develop specifications and testing on an international level.

Question 54

The ideal dental material does not exist.

a. True
b. False

Answer 54

a. True

Question 55

How a dental material interacts with the tissues of the face and mouth is not as important as the function and esthetics of a material. Knowledge of dental materials includes principles of engineering, physics, chemistry, and biology.

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 55

d. The first statement is false; the second statement is true.

Rationale:

Dental materials must be biocompatible with the tissues of the face and mouth, as well as be functional and esthetic. In order to understand how a material will work functionally or be biocompatible, auxiliaries must understand the principles of engineering, physics, chemistry, and biology for appropriate material selection and handling.

Question 56

The Food and Drug Act of 1906 conferred regulatory authority to the FDA and created classifications of medical (dental) devices on the basis of the risk to the public.

a. True
b. False

Answer 56

b. False

Question 57

Dental cements began to be used in the mid-19th century and were zinc oxide with phosphoric acid.

a. True
b. False

Answer 57

a. True

Question 58

An ideal material will not be dissolved in oral fluids. This material would have _______________.

a. high sorption
b. low solubility
c. low sorption
d. high solubility

Answer 58

b. low solubility

Rationale:

Low solubility means a material is not susceptible to being dissolved in a solvent (oral fluids). Sorption refers to a material’s ability to absorb fluids. High solubility would indicate a material is susceptible to dissolving in oral fluids.

Question 59

The electrical current between dissimilar metals that can cause corrosion in dental amalgam is called:

a. galvanism.
b. tarnish.
c. oxidation.
d. shock.

Answer 59

a. galvanism

Question 60

For a bonding agent to have good wettability, it must have a:

a. high contact angle and low viscosity.
b. low contact angle and high viscosity.
c. high contact angle and high viscosity.
d. low contact angle and low viscosity.

Answer 60

d. low contact angle and low viscosity.

Rationale:

Wetting is the degree to which a liquid adhesive is able to spread over the surface of a tooth and restorative material. A low contact angle indicates a material’s ability to spread over a surface, and low viscosity indicates a material is thin and flows well. A high contact angle indicates a material does not spread well across a surface, while high viscosity means a material is thick and does not flow easily.

Question 61

You are mixing materials for placement in a patient’s mouth. You must be careful because the materials you are mixing give off heat when combined. This is called a/an ____________________.

a. coefficient of thermal expansion
b. insulator
c. exothermic reaction
d. dimensional change

Answer 61

c. exothermic reaction

Rationale:

A material that undergoes a reaction that gives off heat is called an exothermic reaction. Care must be taken to prevent subjecting the oral tissues to excess heat. The coefficient of thermal expansion is the measurement used to determine expansion and contraction in a material. Insulators are poor conductors of temperature fluctuations and are used to buffer a tooth or tissue from temperature stimulation. Dimensional changes refer to the expansion and contraction of a material when it is exposed to heating and cooling.

Question 62

A fracture that results over a long period of time when a dental material is subjected to repeated stresses is called:

a. shear.
b. strain.
c. shock.
d. fatigue.

Answer 62

d. fatigue.

Rationale:

Fatigue causes restoration failure from enduring stresses repetitively over time. In addition, moisture, temperature, and pH can also contribute to fatigue of dental materials in the oral cavity. Shear is the force applied when two surfaces slide against each other in opposite directions. Strain is deformation or distortion that occurs when a material cannot resist a stress applied. Shock is the sensation a patient may experience as a result of galvanism.

Question 63

The seepage of harmful materials that is responsible for much of the recurrent decay, marginal staining, and postoperative sensitivity seen in patients is called ___________.

a. interface
b. microleakage
c. percolation
d. retention

Answer 63

b. microleakage

Rationale:

Microleakage is the seepage of harmful materials that is responsible for much of the recurrent decay, marginal staining, and postoperative sensitivity seen in patients and is caused by percolation. Interface is the space between the restoration and the prepped tooth surface. Percolation is the expansion and contraction of a material that allows microleakage to occur in the interface. Retention is the ability of a material to hold its place when subjected to stress forces.

Question 64

Chemical Adhesion occurs when like atoms or molecules bond together.

a. True
b. False

Answer 64

b. False

Question 65

Film thickness is of particular importance with dental cements.

a. True
b. False

Answer 65

a. True

Question 66

The intensity of a color is the ________.

a. translucency
b. hue
c. chroma
d. value

Answer 66

c. chroma

Rationale:

Chroma refers to the intensity/strength of a color. Translucency refers to the ability of a material to reflect light. Hue refers to the dominant color seen. Value describes how light or dark a color is.

Question 67

The normal process of chewing rarely involves one type of stress exerted on a material or a tooth.

a. True
b. False

Answer 67

a. True

Question 68

The term used to describe the change in volume of a material in relation to a change in temperature is:

a. thermal conductivity.
b. modulus of elasticity.
c. coefficient of thermal expansion.
d. percolation.

Answer 68

c. coefficient of thermal expansion.

Rationale:

The coefficient of thermal expansion is the measurement used to determine expansion and contraction in a material. This is important because excessive expansion can result in fractures, while excessive contraction can result in microleakage. Thermal conductivity is the rate at which heat flows through a material over time. Modulus of elasticity measures a material’s ability to resist being permanently deformed when under stress conditions. Percolation is a result of expansion and contraction where fluid and bacteria are able to enter the gap between tooth surface and restoration.

Question 69

The amount of change that a force has applied to a material is called:

a. stress.
b. flexural stress.
c. strain.
d. fatigue.

Answer 69

c. strain.

Rationale:

Strain is the amount of deformation or distortion a material undergoes when it cannot resist stress. Stress is the internal force of a material that resists applied force. Flexural stress involves bending, such as a dental bridge does during normal masticatory functions. Fatigue is the failure of a material after subjection to frequent stress.

Question 70

The dental auxiliary does not need to understand how biomaterials can affect a patient postoperatively because he or she is not placing the material. Restorative materials are expected to remain in contact with oral tissues for short periods of time.

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 70

b. Both statements are false.

Rationale:

An allied oral health practitioner must have a complete understanding of the specific selection, maintenance, hazards, manipulation, and disposal of dental materials. Frequently, it is the responsibility of the allied oral health practitioner to educate the patient in the rationale for restorative and/or therapeutic material selection. Restorative materials are expected to remain in contact with oral tissues for indefinite lengths of time.

Question 71

Your patient is having a restoration done on an anterior tooth. You notice the patient’s teeth are generally yellow in color. In terms of the physical properties of color, this refers to the __________.

a. hue
b. chroma
c. value
d. vitality

Answer 71

a. hue

Rationale:

Hue refers to the dominant color seen. Value describes how light or dark a color is. Chroma refers to the intensity/strength of a color. Vitality refers to the lifelike quality of a material or tooth.

Question 72

Adverse responses to dental materials are due to operator error only.

a. True
b. False

Answer 72

b. False

Question 73

Tactile evaluation of the tooth surface can be a helpful means of clinical assessment.

a. Visual
b. Magnification
c. Illumination
d. Tactile evaluation

Answer 73

d. Tactile evaluation

Rationale:

Well-developed tactile sensitivity skills may be the most reliable means of clinical assessment of a material because the material may have a rougher surface than enamel, or the margin of a restoration may be able to be traced with a sharp explorer. Magnification and illumination, together with drying the surface, are all means to improve visual assessment of materials in the oral cavity. However, due to well-matched tooth-colored restorations being difficult to distinguish, a well-developed tactile sense is necessary beyond these means.

Question 74

The biting force applied in opposite directions that stretches a material is _________ force, while the biting force that is a combination of compressive and tensile forces seen mostly during mastication is _______________.

a. compressive, shearing
b. tensile, torsion
c. shearing, compressive
d. torsion, shearing

Answer 74

b. tensile, torsion

Rationale:

Tensile force is applied in opposite directions, which stretches a material, while torsion is a combination of tensile and compressive forces. Compressive force squeezes or crushes a material. Shearing force occurs when two materials or surfaces slide against each other in opposite directions.

Question 75

Some dental materials may appear radiolucent in radiographs, which is helpful in detecting dental materials.

a. True
b. False

Answer 75

a. True

Question 76

Mechanical retention is the adhesion of a dental material to a bonding material placed on the tooth structure. The use of this bonding material requires less tooth structure to be removed.

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 76

Correct Answer:Close

d. The first statement is false; the second statement is true.

Rationale:

Mechanical retention requires the use of undercuts or projections to retain a restoration. The use of a bonding material is beneficial in that it does require less tooth structure to be removed than mechanical retention.

Question 77

Metals are poor thermal conductors. Enamel and dentin are excellent thermal conductors.

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 77

b. Both statements are false.

Rationale:

Metals are excellent thermal conductors, particularly gold and amalgam. Enamel and dentin are poor thermal conductors and serve as natural insulators from temperature changes to the tooth.

Question 78

It does not matter if you do not use a shade guide, as long as you produce an environment that reduces the chance of producing an inaccurate color.

a. True
b. False

Answer 78

b. False

Question 79

BPA is a chemical found in sealants and composites that is thought to act like a weak estrogen hormone. Wiping the surface of a sealant or composite after curing can remove up to 95% of BPA.

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 79

a. Both statements are true.

Rationale:

BPA is thought to act like a weak estrogen hormone, which has been linked to increased diagnosis of diabetes, obesity, cardiovascular disease, and liver abnormalities in higher levels. Wiping off the uncured oxygen-inhibited layer can reduce the patient’s exposure to BPA by 95%.

Question 80

PPE does not need to be worn in the laboratory, as it is not a patient treatment area.

a. True
b. False

Answer 80

b. False

Question 81

Your office uses National Fire Protection Association (NFPA) labels on containers with hazardous chemicals. What does the color yellow represent on NFPA labels?

a. Flammability
b. Health hazard
c. Reactivity
d. Special notice/hazard

Answer 81

c. Reactivity

Rationale:

Yellow stands for reactivity on NFPA labels. Red stands for flammability; blue stands for health hazard; and white stands for special notice/hazards.

Question 82

When rinsing a ceramic crown that had been etched with hydrofluoric acid, some was splashed into your coworker’s eye. What should be done?

a. Administer oxygen
b. Rinse eyes for 15 minutes
c. Seek medical attention immediately
d. Both b and c

Answer 82

d. Both b and c

Rationale:

It is important to wear proper personal protective equipment (PPE) to protect the eyes from chemicals and aerosols in the dental setting. Hydrofluoric acid is particularly dangerous and can cause permanent damage or blindness. It is important for auxiliaries to know the proper handling of hydrofluoric acid, as well as protocols for accidental exposure to it. These include rinsing the eyes at an eyewash station for 15 minutes and seeking immediate medical attention. Eyewash stations irrigate with wide, soft flows of water to wash away contaminants without causing more damage. The administration of oxygen in this situation is futile.

Question 83

Which of the following precautions should be taken when working with dental amalgam to reduce mercury exposure?

a. Using preloaded amalgam capsules
b. Double gloving
c. Wearing a HEPA mask during amalgam procedures
d. Having a vacuum on hand to clean up amalgam spills

Answer 83

a. Using preloaded amalgam capsules

Rationale:

Using preloaded amalgam capsules reduces exposure by removing the need to measure the mercury and add it to the amalgam. It is important to reassemble amalgam capsules immediately after dispensing, as they are a major source of amalgam vapor. Double gloving is not standard protocol for reducing mercury exposure during amalgam procedures. Additionally, treatment gloves are not adequate protection when handling most chemicals. HEPA masks are used to reduce particulate inhalation with gypsum product use. Use of a vacuum can release mercury vapors into the air, and these vapors may remain in the vacuum, causing repeated release of mercury vapors.

Question 84

An office must only keep and file the SDSs of hazardous chemicals used in the office.

a. True
b. False

Answer 84

b. False

Question 85

Aerosols can remain airborne for hours. Lasers do not create aerosols.

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 85

c. The first statement is true; the second statement is false.

Rationale:

Due to their small size, aerosols can stay airborne for minutes to hours. Lasers and other electrosurgical units produce aerosols that contain tissue debris and other infectious materials.

Question 86

Aerosols can remain airborne for hours. Lasers do not create aerosols.

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 86

c. The first statement is true; the second statement is false.

Rationale:

Due to their small size, aerosols can stay airborne for minutes to hours. Lasers and other electrosurgical units produce aerosols that contain tissue debris and other infectious materials.

Question 87

The Occupational Safety and Health Administration regulation that requires dental offices to have information on all the chemicals used in the office available to employees is called what?

a. Exposure control
b. Hazard Communication Standard
c. ALARA
d. Standard precautions

Answer 87

b. Hazard Communication Standard

Rationale:

The Hazard Communication Standard was mandated because employees have the right to be aware of what chemicals they are using and/or are exposed to in the workplace. Exposure control deals with exposure to bloodborne pathogens and controlling or minimizing incidents of accidental exposure through such things as needle sticks. ALARA is a principle related to minimizing radiation exposure for patients having dental radiographs. Standard precautions refer to the use of all PPE equipment for each patient.

Question 88

The purpose of OSHA’s Hazard Communication Standard is to protect patients in the dental office from exposure to chemicals.

a. True
b. False

Answer 88

b. False

Question 89

You need to get more acrylic powder out of the bottle during a procedure. Which of the following would be an appropriate means of avoiding contamination of the bottle?

a. Check the Safety Data Sheet (SDS)
b. Have appropriate ventilation
c. Pour the acrylic powder carefully
d. Use overgloves

Answer 89

d. Use overgloves

Rationale:

It is important to use overgloves or plastic covers when handling the bottles, cans, or tubes that contain dental materials during a procedure. Checking the SDS will not help with infection control during a procedure. Appropriate ventilation and pouring materials (instead of spraying) are ways to minimize aerosols and particulates in the air.

Question 90

Which of the following can be used to reduce bio-aerosols?

a. Pre-procedural rinses
b. Brushing and flossing
c. High-volume suction
d. All of the above

Answer 90

d. All of the above

Rationale:

Pre-procedural rinses, brushing and flossing, high-volume suction, and coronal polishing before procedures are all recommended to reduce bio-aerosols during dental procedures.

Question 91

Some manufactures occasionally suggest running eyewash stations to discharge potential built up biofilms or infectious agents.

a. True
b. False

Answer 91

a. True

Question 92

Hazard communication programs must include staff training whenever a new chemical is purchased for the office. Employers must provide employees with annual hazard communication training.

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 92

a. Both statements are true.

Rationale:

Staff training is required annually and is to be provided by the employer. In addition, anytime a new chemical is added to the office’s inventory, all staff must receive training on that new chemical.

Question 93

The written portion of an office’s chemical hazard communication program must contain which of the following?

a. A list of the companies the chemicals were purchased from
b. A list of all employees exposed to hazardous chemicals
c. A narrative for patients discussing the chemicals in materials used during a procedure
d. Posters in the waiting room regarding chemicals used in the office

Answer 93

b. A list of all employees exposed to hazardous chemicals

Rationale:

Any hazard communication program must contain a list of names of all employees who are exposed to hazardous chemicals.