Chapter 1, 2, and 4 Flashcards
1
Q
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
A
Adhesion
2
Q
An unintended, unexpected, and harmful or unwelcome response of an individual to dental treatment or biomaterial
A
adverse response
3
Q
materials used to fabricate and maintain restorations, directly or indirectly
A
auxiliary materials
4
Q
the property of a material that allows it not to impede or adversely affect living tissue
A
biocompatible
5
Q
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
A
biofilm
6
Q
to connect or fasten; to bind
A
bonding
7
Q
the intensity or strength of a color (e.g., a bold yellow has more chroma than a pastel yellow)
A
chroma
8
Q
coefficient of thermal expansion
A
the measurement of change in volume or length in relationship to change in temperature
9
Q
compressive force
A
force applied to compress an object
10
Q
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)
A
corrosion
11
Q
dimensional change
A
a change in the size of matter. For dental materials, this usually manifests as expansion
12
Q
exothemric reaction
A
the production of heat resulting from the reaction of the components of some materials when they are mixed
13
Q
a fractures resulting from repeated stresses that produce microscopic flaws that grow
A
fatigue failure
14
Q
film thickness
A
the minimal obtainable thickness of a layer of material. It is particularly important in the context of dental cements
15
Q
flexural stress
A
bending caused by a combination of tension and compression
16
Q
fracture toughness
A
a measure of the energy needed to fracture a material
17
Q
galvanism
A
an electrical current transmitted between two dissimilar metals in a solution of electrolytes
18
Q
hue
A
the color of a tooth or restoration. It may include a mixture of colors, such as yellow-brown
19
Q
insulators
A
materials having low thermal conductivity
20
Q
interface
A
the surface between the walls of preparation and the restoration or between two dental materials
21
Q
microleakage
A
leakage of fluid and bacteria caused by microscopic gaps that occur at the interface of the tooth and the restoration margins
22
Q
opaque
A
optical property in which light is completely absorbed by an object
23
Q
percolation
A
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
24
Q
Resilience
A
a measure of the energy needed to permanently deform a material
25
restorative materials
materials used to reconstruct tooth structure
26
retention
material's ability to maintain its position without displacement under stress
27
shearing force
force applied when to surfaces slide against eachother
28
solubility
susceptible to being dissolved
29
strain
distortion or deformation that occurs when an object cannot resist a force
30
the internal force, which resists the applied force
stress
31
the electrical charge that attracts atoms to a surface
surface energy
32
discoloration resulting from oxidation of a thin layer of a metal at its surface. It is not as destructive as corrosion
tarnish
33
tensile force
force applied in opposite directions to stretch an object
34
therapeutic materials
materials used to treat disease
35
Torsion or torque
a twisting force that combines tensile and compressive forces
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36
optical property in which varying degrees of light pass through or are absorbed by an object
transluceny
37
optical property in which light passes directly through an object
transparent
38
ultimate strength
the maximum amount of stress a material can withstand without breaking
39
value
how light or dark a color is. A low value indicates a darker color and a high value indicates a brighter color
40
viscosity
the ability of a liquid material to resist flow, e.g. ketchup is more viscous than water
41
vitality
a life-like quality
42
water sorption
the ability to absorb moisture
43
44
wetting
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
45
Scientific evidence replaces clinical expertise in evidence-based dentistry true or false?
False
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.
## Footnote
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.
c. The first statement is true, the second statement is false
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.
## Footnote
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.
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.
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
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.
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
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.
50
Humans have suffered from dental disease for millennia. However, the first evidence of restorative dentistry appeared when?
## Footnote
a. 1.7 million years ago
b. 2500 BC
c. 600 BC
d. The 18th century
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.
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
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.
52
Once used as a paste, silver has been used as a restorative material since the 7th century.
a. True
b. False
a. True
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
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.
54
The ideal dental material does not exist.
a. True
b. False
a. True
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.
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.
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.
## Footnote
a. True
b. False
b. False
57
Dental cements began to be used in the mid-19th century and were zinc oxide with phosphoric acid.
a. True
b. False
a. True
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
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.
59
The electrical current between dissimilar metals that can cause corrosion in dental amalgam is called:
a. galvanism.
b. tarnish.
c. oxidation.
d. shock.
a. galvanism
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.
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.
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
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.
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.
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.
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
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.
64
Chemical Adhesion occurs when like atoms or molecules bond together.
a. True
b. False
b. False
65
Film thickness is of particular importance with dental cements.
a. True
b. False
a. True
66
The intensity of a color is the \_\_\_\_\_\_\_\_.
a. translucency
b. hue
c. chroma
d. value
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.
67
The normal process of chewing rarely involves one type of stress exerted on a material or a tooth.
## Footnote
a. True
b. False
a. True
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.
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.
69
The amount of change that a force has applied to a material is called:
a. stress.
b. flexural stress.
c. strain.
d. fatigue.
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.
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.
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.
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 \_\_\_\_\_\_\_\_\_\_.
## Footnote
a. hue
b. chroma
c. value
d. vitality
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.
72
Adverse responses to dental materials are due to operator error only.
## Footnote
a. True
b. False
b. False
73
Tactile evaluation of the tooth surface can be a helpful means of clinical assessment.
a. Visual
b. Magnification
c. Illumination
d. Tactile evaluation
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.
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
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.
75
Some dental materials may appear radiolucent in radiographs, which is helpful in detecting dental materials.
a. True
b. False
a. True
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.
## Footnote
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.
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.
77
Metals are poor thermal conductors. Enamel and dentin are excellent thermal conductors.
## Footnote
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.
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.
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
b. False
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.
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%.
80
PPE does not need to be worn in the laboratory, as it is not a patient treatment area.
## Footnote
a. True
b. False
b. False
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
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.
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
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.
83
Which of the following precautions should be taken when working with dental amalgam to reduce mercury exposure?
## Footnote
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
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.
84
An office must only keep and file the SDSs of hazardous chemicals used in the office.
a. True
b. False
b. False
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.
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.
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.
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.
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?
## Footnote
a. Exposure control
b. Hazard Communication Standard
c. ALARA
d. Standard precautions
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.
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
b. False
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
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.
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
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.
91
Some manufactures occasionally suggest running eyewash stations to discharge potential built up biofilms or infectious agents.
## Footnote
a. True
b. False
a. True
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.
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.
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
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.
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