Dental Materials and Radiology
Semester 2 Final Exam Study Guide
Multiple Choice: Choose the most correct answer.
1. Which of the following choices represents a developmental cause of orthodontic
problems?
a. interference with eruption
b. jaw size discrepancy
c. fetal molding
d. damage to permanent tooth buds when an injury to primary teeth has
occurred
2. Class II occlusion _____.
a. is normal occlusion
b. is mesioclusion
c. occurs when the maxillary teeth are too far forward in relation to the
mandibular teeth ( “buck teeth” )
d. occurs when the mandibular teeth are too far forward in relation to the
maxillary teeth ( like a bulldog )
3. The radiograph most commonly exposed for an orthodontic patient is the _____.
a. FMX
b. panoramic
c. cephalometric
d. bite-wing
4. The most common type of attachment for holding arch wires is the _____.
a. orthodontic band
b. bonded bracket
c. arch wire
d. separator
5. Orthodontic problems come from which of the following:
1) developmental, 2) genetic, 3) environmental, 4) functional influences.
a. 1, 2, 3, 4
b. 1, 2, 3
c. 1, 2
d. 1
6. Dental arch wires are held in place by _____.
a. ligature ties (thin wire)
b. dental cement
c. elastomeric ties (rubber bands)
d. both a and c
7. Which environmental surfaces must be cleaned and decontaminated more
thoroughly than the others?
a. housekeeping surfaces
b. clinical contact surfaces
c. floors and walls
d. sinks
8. The method to deal with surface contamination is _____.
a. using a surface barrier to prevent the surface from becoming contaminated
b. pre-cleaning and disinfecting the surface between patients
c. wiping the surface with alcohol
d. both a and b
9. Chemicals that destroy or inactivate most species of pathogenic microorganisms on
inanimate surfaces are called _____.
a. disinfectants
b. steripads
c. antiseptics
d. both a and c
10. Precautions that should be followed when using strong sterilization chemicals like
glutaraldehyde include _____.
a. avoiding the fumes
b. always rinsing instruments thoroughly before using them on patients
c. wearing PPE to protect the eyes, skin, and lungs
d. all of the above
11. Carpeting _____.
a. is as easy to clean as nonporous hard-surface flooring
b. can be reliably disinfected
c. harbors bacteria but not fungi
d. harbors both bacteria and fungi
12. A(n) _____ is defined as a mixture of two or more metals.
a. alloy
b. amalgam
c. ceramic
d. porcelain
13. A liquid with high viscosity _____ flow easily and _____ in wetting a surface.
a. does; is effective
b. does; is not effective
c. does not; is effective
d. does not; is not effective
14. Dental restorative materials that are applied, while pliable, to a tooth or teeth and can be
adapted, carved, and finished are classified as _____.
a. indirect restorations
b. direct restorations
c. crowns and bridges
d. implants
15. The silver filling material used for over 150 years to restore primary and permanent teeth
is called _____.
a. amalgam
b. composite
c. glass ionomer
d. acrylic resin
16. _____ is added to dental amalgam alloy powder to suppress oxidation.
a. Silver
b. Tin
c. Copper
d. Zinc
17. The conventional or traditional composites, which contain the largest filler particles and
provide the greatest strength, are known as _____.
a. microfilled composites
b. midfilled composites
c. hybrid composites
d. macrofilled composites
18. _____ is the process by which the resin material is changed from a pliable state into a
hardened restoration.
a. Trituration
b. Retention
c. Polymerization
d. Galvanism
19. Glass ionomer can be used for Class _____ restorations.
a. II
b. III
c. IV
d. V
20. Which of the following are advantages to using glass ionomer as a restorative material?
a. Glass ionomer has the ability to bind to teeth mechanically, rather than chemically.
b. Glass ionomer releases fluoride after its final setting.
c. Loss of gloss indicates a proper mix of glass ionomer material.
d. There is no need to avoid contact with water during the mixing procedure for glass
ionomer.
21. If a tooth has _____, an intermediate restorative material should be selected for now.
a. lost a restoration
b. a missing cusp
c. been prepared for a cast restoration
d. been prepared for a porcelain veneer
22. Intermediate restorative material (IRM) is a _____.
a. zinc polycarboxylate cement
b. composite resin
c. zinc oxide-eugenol cement
d. ceramic
23. In most states, an expanded-functions dental assistant may perform which of the
following functions?
a. placing IRM
b. using a high-speed handpiece for cavity preparation
c. applying a provisional restoration
d. both a and c
24. One of the fastest and most cost-effective ways of restoring the esthetic appearance of
teeth is _____.
a. bleaching
b. porcelain veneers
c. composite veneers
d. ceramic crowns
25. The dental restorations created in the laboratory by the dental laboratory technician are
classified as _____.
a. direct restorations
b. indirect restorations
c. provisional restorations
d. amalgams
26. _____ is a metal used for full crowns in dentistry.
a. Gold
b. Iron
c. Tin
d. Zinc
27. The type of ceramic most often used in dentistry for castings is _____.
a. composite resin
b. glass ionomer
c. zinc oxide-eugenol cement
d. porcelain
28. Nearly _____% of all cavities occur in the pits and fissures of posterior teeth.
a. 24
b. 44
c. 74
d. 84
29. Sealants are indicated for _____.
a. children but not adults
b. posterior but not anterior teeth
c. the smooth surfaces of teeth but not pits and fissures
d. some maxillary central and lateral incisors
30. Contraindications to sealant placement include proximal decay, because _____.
a. proximal decay will spread to and undermine the occlusal surface
b. posterior proximal tooth preparation will usually include the occlusal pits and
fissures
c. sealants are placed on smooth surfaces and the proximal area is a smooth surface
d. sealants are placed on smooth surfaces and the proximal area is a rough surface
31. Light-cured sealant materials _____.
a. require mixing
b. are supplied as a two-part system
c. are superior in bond strength and rates of retention to self-cured sealants
d. are polymerized by chemicals in the sealant reacting to the light
32. The most common cause of sealant loss is _____.
a. use of unfilled material
b. use of outdated material
c. moisture contamination during placement
d. bruxism
33. The first step in placing dental sealants is to _____ the surface.
a. etch
b. isolate
c. clean (with pumice) and rinse
d. prime
34. A sealant that is polymerized by chemical reactions is called _____.
a. acrylate
b. filled resin
c. self-cured
d. unfilled resin
35. Self-cured sealant materials are supplied as a two-part system that includes _____.
a. a base
b. a catalyst
c. filled resins
d. both a and b
36. The retention of the sealant is obtained by etching the enamel with _____, to roughen it
and open the pores in enamel for penetration of the resin sealant.
a. citric acid
b. phosphoric acid
c. eugenol
d. pumice
37. The primary reason why very few children are protected by dental sealants is _____.
a. they are not recommended by the American Dental Association
b. they have not been shown to significantly reduce decay
c. lack of public awareness
d. they are not effective for prevention of pit and fissure decay in posterior teeth
38. The uses of dental radiographs include the detection of _____.
a. incipient occlusal carious lesions
b. periodontal probing depths
c. bone loss
d. sensitivity as part of endodontic evaluation
39. Exposure to radiation _____.
a. no matter how small, has the potential to cause harmful biologic changes
b. has a threshold, below which exposure is entirely safe
c. is safer when there is a single, large dose rather than a series of smaller doses
d. from a dental x-ray machine does not involve particulate radiation and is
completely safe
40. The x-ray was discovered on November 8, 1895, by _____.
a. John Greenwood
b. Wilhelm Conrad Roentgen
c. G. V. Black
d. Edmund Kells
41. The dentist who is credited with the first practical use of radiographs in dentistry in 1896
is _____.
a. Wilhelm Conrad Roentgen
b. G. V. Black
c. C. Edmund Kells
d. John Greenwood
42. Anything that occupies space and has a form or shape is _____.
a. energy
b. solid
c. matter
d. a photon
43. Which of the following statements is true concerning the structure of the atom?
a. The nucleus contains protons and electrons.
b. Electrons have no weight or mass.
c. The orbital path of an electron around the nucleus is called an electron shell.
d. Electrons are unstable in their orbits and shift freely.
44. In dentistry, the _____ the wavelengths of the x-rays, the greater their energy and their
usefulness.
a. shorter
b. longer
c. more ionized
d. straighter
45. Which component of the x-ray machine functions in positioning the tube head?
a. kilovoltage selector
b. control panel
c. extension arm
d. cathode
46. The heart of the x-ray generating system is the _____.
a. x-ray tube
b. insulating oil
c. transformer
d. position indicator device
47. Secondary radiation _____.
a. is often referred to as the useful beam
b. is often referred to as the primary beam
c. refers to x-ray radiation that is created when the primary beam explodes
d. is a form of radiation that occurs when an x-ray beam has been deflected from its
path by interaction with matter
48. Which of the following structures will appear radiopaque on dental x-ray film?
a. metal restorations
b. soft tissue
c. tooth decay
d. dental pulp
49. The term _____ is used to describe areas that appear dark on the radiograph; _____ is the
term used to describe areas that appear white or light gray.
a. radiopaque; radiolucent
b. radiolucent; radiopaque
c. density; contrast
d. contrast; density
50. The range of shades of gray between black and white on a radiograph is _____.
a. contrast
b. density
c. sharpness
d. focus point
51. The degree of density or blackness on a radiograph is controlled by _____.
a. the film speed
b. the kilovoltage
c. the milliampere-seconds
d. the position indicating device
52. One of the rules of radiation protection is to never stand closer than _____ feet from the
x-ray unit during an exposure unless you are behind a barrier.
a. 2
b. 6
c. 10
d. 15
53. Damage caused by ionizing x-ray radiation to genetic cells _____.
a. affects only the person being x-rayed
b. can affect future generations
c. affects only the dental assistant
d. affects the cells of the eye, skin, and oral mucosa.
54. Which of the following tissues has the highest radiation sensitivity?
a. small lymphocytes
b. salivary gland
c. kidney
d. muscle tissue
55. A lead apron and thyroid collar _____.
a. are utilized for a full mouth series of films but are not necessary for single
periapical films
b. must be used on all patients for all exposures
c. is required for pediatric patients but is optional for adults
d. is mandated only for pregnant women
56. Dentists recommend which of the following dental radiographic procedures for a
pregnant patient?
a. Do not take radiographs on a pregnant patient unless it is an emergency.
b. Radiographic procedures do not need to be altered because of pregnancy.
c. Take x-rays only during the last trimester.
57. The bite-wing radiograph is used for _____.
a. detecting abscessed teeth
b. detecting periodontal disease
c. detecting interproximal decay
d. both b and c
58. A periapical radiograph shows the tooth from the occlusal surface or incisal edge to the
_____.
a. top of alveolar bone
b. furcation
c. apex of the root
d. bone about 2 to 3 mm beyond the apex
59. An intraoral full-mouth set of x-rays (FMX) on an adult consists of _____.
a. 18 to 20 films
b. 4 films
c. 10 periapicals and 2 bite-wings
d. 4 anterior films and 8 posterior films
60. The bite-wing film shows _____.
a. the crowns and interproximal areas of the maxillary and mandibular teeth
b. the whole tooth crown to apex and surrounding bone
c. the top of the bone
d. both a and c
61. A total of _____ bite-wing films are taken on an adult patient.
a. two
b. four
c. six
d. eight
62. Radiographs on an edentulous patient might be required for _____.
a. forensic identification purposes
b. identifying objects embedded in the bone
c. detecting retained root tips, impacted teeth, and lesions
d. both b and c
63. A radiographic mount should always be labeled with _____.
a. the patient’s name
b. the operator’s name
c. the patient’s name and the date the films were exposed
d. the patient’s name and the date the films were processed
64. The American Dental Association recommends that films be mounted _____.
a. with the dot facing toward the person viewing
b. with the dot facing away from the person viewing
c. as if the viewer is standing on the patient’s tongue
d. so the patient’s left side is on the viewer’s left side
65. Tylenol is a _____ name for acetaminophen.
a. chemical
b. O.S.H.A.
c. brand or trade
d. U.S. Food, Drug, and Cosmetic Act
66. Patent medicines are also known as _____.
a. over-the-counter drugs
b. prescription drugs
c. ethical drugs
d. generic drugs
67. _____ can be obtained only from a pharmacist who has been provided with a prescription
from a physician or dentist.
a. Patent medicines
b. Over-the-counter drugs
c. Prescription drugs
d. All drugs
68. The part of the prescription that includes the name and quantity of the drug is the _____.
a. superscription
b. subscription
c. inscription
d. signature
69. The dental assistant should _____ when a pharmacy calls the dental office regarding a
prescription.
a. authorize prescriptions for narcotics for extreme pain over the phone, if necessary,
b. notify the dentist immediately.
c. relay information between the pharmacist and dentist and not interrupt either of
them
d. tell the pharmacist to call back again later if the dentist is busy with a patient
70. A professional who is authorized to prescribe medications must have _____.
a. a federal Drug Enforcement Agency (DEA) identification number
b. a prescription pad
c. a medical or dental office
d. both a and b
71. Prophylactic antibiotics are used in dentistry to _____.
a. prevent infective endocarditis
b. treat fungal infections
c. treat herpes infections
d. relieve anxiety
72. When a patient has taken a drug over time and the drug has lost its effectiveness, the
patient has developed _____.
a. a drug tolerance
b. a drug interaction
c. a drug addiction
d. an allergic reaction
73. The prescription abbreviation b.i.d. stands for _____ day.
a. every
b. twice a
c. three times a
d. four times a
True or False: On your Scantron answer sheet choose A for True and B for False.
74. An antiseptic is more effective than a disinfectant.
75. The purpose of an ultrasonic cleaner is to kill bacteria with sound waves.
76. If you soak dental instruments long enough in a liquid sterilizing solution you
don’t have to use the autoclave on them.
77. The last step of applying a dental pit and fissure sealant is to check/adjust the
patient’s bite.
78. You never should apply an acid etchant to dentin.
79. The next two steps in composite resin placement after applying etchant is to
apply the bonding liquid and then rinse with water.
80. The primer is applied after the bonding liquid when doing a composite filling.
81. The primer is rinsed off with water before curing it with the composite light
when doing a composite filling.
82. You should never look directly at the composite light without colored goggles.
83. Composite lights get very hot and will burn the patient’s lip if you touch it.
84. Acid etchant is applied to remove the primer when doing a composite filling.
85. You don’t have to apply primer and bonding liquid if you think the composite
filling material will stay in the tooth by itself.
86. The patient light will begin hardening composite resin if it is exposed for several
minutes.
87. If you work out in the sun a lot you should choose amalgam fillings instead of
composite to avoid a chemical reaction.
88. Amalgam is a better choice if cost is your most important factor.
89. Composite resin fillings seal against the tooth better than amalgam when placed
in between teeth.
90. Gold is a longer-lasting material than composite or amalgam.
91. There is overwhelming evidence that the mercury in amalgam poses a serious
health hazard.
92. The most biocompatible material used in dentistry is gold.
93. Porcelain is a much rougher surface than polished gold when doing crowns.
94. The person most commonly taking and pouring alginate impressions in the
dental office is the dental assistant.
95. Dental assistants are never allowed to take final impressions in Nevada.
Essay Questions: Answer the following questions on a separate piece of paper using
complete sentences. (25 points each)
1. Describe the process of making bleaching trays for a patient from the moment
you greet the patient to the procedure for delivering the trays. Include, in detail,
all the lab procedures done along the way.
2. Describe at least two advantages and two disadvantages of using gold, porcelain,
composite resin and amalgam in restoring teeth.