Exam 1 (1-4, & 9)

Question 1

1. Who was awarded the first Nobel Prize for physics in 1901, for his experimental work with radiation?
   a. W. J. Morton
   b. O. Walkhoff
   c. W. D. Coolidge
   d. W. C. Roentgen

Answer 1

d. Wilhelm Conrad Roentgen

(He discovered the x-ray on November 8, 1895, when he noted that a fluorescent screen near a Crookes vacuum tube began to glow when an electric current was passed through the tube.)

Question 2

2. Who is credited with introducing the bitewing radiograph?
   a. F. W. McCormack
   b. H. R. Raper
   c. G. M. Fitzgerald
   d. C. E. Kells

Answer 2

b. Howard Riley Raper

(wrote the first dental radiology textbook, Elementary and Dental Radiology, and introduced bitewing radiographs in 1925)

Question 3

3. Who developed the hot cathode ray tube?
   a. W. D. Coolidge
   b. W. A. Price
   c. H. R. Raper
   d. W. H. Rollins

Answer 3

a. William David Coolidge

(developed the shockproof hot cathode tube while working for the General Electric Company in 1913.)

Question 4

4. The development of radiation protection as a science is credited to:
   a. A. Cieszyński.
   b. W. D. Coolidge.
   c. W. H. Rollins.
   d. F. Mouyen.

Answer 4

William Herbert Rollins

(was one of the first to alert the profession to the need for radiation hygiene and protection, and is considered by many to be the first advocate for the science of radiation protection.)

Question 5

5. What New Orleans dentist first made practical use of x-rays in the treatment of dental patients?
   a. H. R. Raper
   b. G. M. Fitzgerald
   c. F. Mouyen
   d. C. E. Kells

Answer 5

d. C. Edmund Kells

(took the first dental radiograph on a living subject in the United States. He was the first to put the radiograph to practical use in dentistry. Dr. Kells made numerous presentations to organized dental groups and was instrumental in convincing many dentists that they should use oral radiography as a diagnostic tool.)

Question 6

6. Early researchers working in the field of radiography were not aware that continued exposure to x-rays produced accumulations of radiation effects in the body because x-rays are invisible.
   a. Both the statement and reason are correct and related.
   b. Both the statement and reason are correct but NOT related.
   c. The statement is correct, but the reason is NOT.
   d. The statement is NOT correct, but the reason is correct.
   e. NEITHER the statement NOR the reason is correct.

Answer 6

a. Both the statement and reason are correct and related.

(Because x-rays are invisible, scientists and researchers working in the field of radiography were not aware that continued exposure produced accumulations of radiation effects in the body and therefore could be dangerous to both patient and radiographer.)

Question 7

7. The most significant advancement in the early days of radiography came in 1913 when W. D. Coolidge:
   a. became the first to alert the profession of the dangers of radiation exposure and advocated for the science of radiation protection.
   b. exposed a prototype of a dental radiograph, setting the stage for preventive oral health care.
   c. developed a variable, high kilovoltage x-ray machine compatible with the paralleling technique.
   d. introduced an x-ray tube that allowed for an x-ray output that could be predetermined and accurately controlled.

Answer 7

d. introduced an x-ray tube that allowed for an x-ray output that could be predetermined and accurately controlled.

(The introduction of the Coolidge tube allowed for an x-ray output that could be predetermined and accurately controlled.)

Question 8

8. The first dental radiograph was produced using an exposure time of:
   a. 0.5 second.
   b. 1 minute.
   c. 5 minutes.
   d. 25 minutes.
   e. 1 hour.

Answer 8

d. 25 minutes.

(Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes that he held the film in his mouth.)

Question 9

9. What component of the dental x-ray machine best limits the size of the x-ray beam to the approximate size of the image receptor?
   a. A pointed cone
   b. An open round cylinder
   c. A rectangular PID
   d. A slit collimator

Answer 9

c. A rectangular PID

(A rectangular position indicating device (PID) limits the size of the x-ray beam that strikes the patient to the actual size of the image receptor.)

Question 10

10. Panoramic radiology became popular in the:
    a. 1930s.
    b. 1940s.
    c. 1950s.
    d. 1960s.
    e. 1970s.

Answer 10

d. 1960s.

(Panoramic radiography became popular in the 1960s with the introduction of the panoramic x-ray machine.)

Question 11

11. Which of the following is NOT true regarding cone beam volumetric imaging?
    a. It images a single selected plane of tissues.
    b. It is based on computed tomography.
    c. It uses less radiation than a panoramic radiograph.
    d. It is designed specifically for imaging dental applications.
    e. It is purported to become the gold standard for imaging certain oral conditions.

Answer 11

c. It uses less radiation than a panoramic radiograph.

(While cone beam volumetric imaging dedicated to dental applications produces less radiation doses than conventional CT scans, the dose is still 4 to 15 times that required for a panoramic radiograph.)

Question 12

12. Early dental film required long exposure times because:
    a. it was hand-wrapped.
    b. the emulsion was only on one side.
    c. glass plates were used as the base.
    d. the packets were not moisture resistant.

Answer 12

b. the emulsion was only on one side.

(Early film had emulsion on only one side and required long exposure times.)

Question 13

13. Each of the following is an advantage of digital imaging EXCEPT one. Which one is the EXCEPTION?
    a. It reduces radiation over film-based radiography.
    b. It eliminates the need for the darkroom and processing chemistry.
    c. It allows the use of pointed cones without radiation hazards.
    d. It avoids the need for disposal of hazardous materials such as lead foils from film packets.
    e. It produces enhanced two- and three-dimensional images.

Answer 13

c. It allows the use of pointed cones without radiation hazards.

(Pointed cones are no longer acceptable because x-rays are scattered through contact with the material of pointed cones.)

Question 14

14. The bisecting technique was the first and earliest radiographic technique for exposing intraoral radiographs because the bisecting technique is based on the rule of isometry.
    a. Both the statement and reason are correct and related.
    b. Both the statement and reason are correct but NOT related.
    c. The statement is correct, but the reason is NOT.
    d. The statement is NOT correct, but the reason is correct.
    e. NEITHER the statement NOR the reason is correct.

Answer 14

b. Both the statement and reason are correct but NOT related.

(The bisecting technique is based on the rule of isometry, but this is not the reason that it was the first and earliest radiographic technique for exposing intraoral radiographs.)

Question 15

15. The paralleling technique is taught in all dental assisting, dental hygiene, and dental schools because it is the technique of choice for imaging intraoral radiographs.
    a. Both the statement and reason are correct and related.
    b. Both the statement and reason are correct but NOT related.
    c. The statement is correct, but the reason is NOT.
    d. The statement is NOT correct, but the reason is correct.

Answer 15

a. Both the statement and reason are correct and related.

(Because the newer technique of paralleling improved on the older bisecting technique, it is the technique of choice and taught in all dental assisting, dental hygiene, and dental schools.)

Question 16

16. The rule of isometry is the basis for what dental radiographic technique?
    a. Bisecting
    b. Paralleling
    c. Panoramic
    d. Digital
    e. Computed tomography

Answer 16

a. Bisecting

(In 1907, A. Cieszyński, a Polish engineer, applied the “rule of isometry ”to dental radiology and is credited for suggesting the bisecting technique.)

Question 17

17. Each of the following is a potential use of dental radiographs EXCEPT one. Which one is the EXCEPTION?
    a. Diagnosing dental caries
    b. Evaluating development of dentition
    c. Detecting missing teeth
    d. Assessing patient self-care
    e. Evaluating trauma to teeth and supporting bone

Answer 17

d. Assessing patient self-care

(Home care is best determined during a visual clinical examination that would assess the presence of biofilms and the condition of the gingival tissues. –> Holding the film in the patient’s mouth exposes the radiographer to unnecessary radiation.)

Question 18

18. Producing radiographs of the teeth and/or the oral cavity is called:
    a. Radiation producing.
    b. Radiology.
    c. Roentgenograph.
    d. X-raying.
    e. Radiography.

Answer 18

e. Radiography.

(Radiography is defined as the making of radiographs by exposing and processing x-ray film.)

Question 19

19. Dental assistants and dental hygienists meet an important need by providing each of the following EXCEPT one. Which one is the EXEPTION?
    a. Exposing radiographs
    b. Processing radiographs
    c. Mounting radiographs
    d. Prescribing radiographs
    e. Interpreting radiographs

Answer 19

d. Prescribing radiographs

(Dentists have the authority and responsibility for prescribing and diagnosing conditions from dental radiographs. Dentists, dental assistants, and dental hygienists can expose, process, mount, and interpret (read) dental radiographs.)

Question 20

20. The positioning indicating device (PID) is sometimes called a “cone” because the PID of early dental x-ray machines was of a pointed shape.
    a. Both the statement and reason are correct and related.
    b. Both the statement and reason are correct but NOT related.
    c. The statement is correct, but the reason is NOT.
    d. The statement is NOT correct, but the reason is correct.
    e. NEITHER the statement NOR the reason is correct.

Answer 20

a. Both the statement and reason are correct and related.

(Because cones were used for so many years, many still refer to the open cylinders or rectangular tubes as cones.)

Question 21

1. William Herbert Rollins was awarded the first Nobel Prize for physics. T/F

Answer 21

False.

(William Conrad Roentgen was awarded the first Nobel Prize for physics in 1901 for the discovery of the x-ray. )

Question 22

2. C. Edmund Kells encouraged the practical use of radiographs in dentistry. T/F

Answer 22

True.

(C. Edmund Kells took the first dental radiograph on a living subject in the United States. He made many presentations to organized dentistry advocating the use of dental radiographs as a diagnostic tool.)

Question 23

3. The radiographer should help the patient hold the image receptor in place during exposure. T/F

Answer 23

False.

(Continued exposure results in the accumulation of radiation effects in the body that can be dangerous to the radiographer.)

Question 24

4. In the early 1900s dental patients would have to be sent to hospitals or a physician’s office to have a dental radiograph exposed. T/F

Answer 24

True.

(It was customary to send the patient to a hospital or physician’s office on those rare occasions when dental radiographs were prescribed.)

Question 25

5. Early dental x-ray machines were an electrical hazard.

Answer 25

True. (Dental x-ray machines manufactured before 1920 were an electrical hazard because of open, uninsulated, high-voltage supply wires.)

Question 26

6. Pointed cones should be used to direct radiation from the x-ray tube to the patient. T/F

Answer 26

False. (Pointed cones allow x-ray scatter to reach the patient through contact with the material of the cone.)

Question 27

7. Dental x-ray film available today is coated with emulsion on both sides. T/F

Answer 27

True. (Early x-ray films were single emulsion only and required long exposure times. Today’s films are double emulsion and require much shorter exposure times.)

Question 28

8. The bisecting technique is the technique of choice for intraoral radiography.

Answer 28

False. (The paralleling technique is less complicated and produces better radiographs more consistently than the bisecting technique.)

Question 29

9. Dental radiography supplements visual and physical examination to provide a quality evaluation of a patient. T/F

Answer 29

True. (Many conditions may go undetected without radiographic examination.)

Question 30

10. Digital imaging systems can reduce radiation dosage more than film-based radiography. T/F

Answer 30

True. (Digital sensors that replace film are more sensitive to x-rays, allowing for a reduction in radiation dose, one of the biggest advantages of digital imaging over film-based radiographs.)

Question 31

11. A radiograph is an image produced by exposure to x-rays. T/F

Answer 31

True. The definition of radiograph is an image produced on photosensitive film by exposure to x-rays.

Question 32

12. Computed tomography eliminates the use of radiation to produce an image. T/F

Answer 32

False. (Computed tomography or CT scans deliver high radiation doses, sometimes up to 600 times more than a panoramic radiograph.)

Question 33

13. Digital imaging replaces the conventional dental x-ray machine. T/F

Answer 33

False. (In digital radiography a sensor replaces film. The conventional dental x-ray machine is used for both digital and film-based imaging.)

Question 34

14. The paralleling technique is based on the rule of isometry. T/F

Answer 34

False. (The bisecting technique is based on the rule of isometry.)

Question 35

15. The PID is used to direct the useful beam of radiation. T/F

Answer 35

True. (PID stands for position indicating device, which means that the PID is used to direct the useful beam of radiation toward the patient and the image receptor.)

Question 36

16. X-radiation was discovered when Roentgen was working with a Crookes tube. T/F

Answer 36

True. (Roentgen discovered x-radiation while working with a Crookes tube (named after William Crookes, an English chemist). The Coolidge tube is named after William David Coolidge who, while working for the General Electric Company, introduced the hot cathode tube that allowed x-ray output to be predetermined and accurately controlled.)

Question 37

17. Roentgen named his discovery the roentgen ray. T/F

Answer 37

False. Roentgen reported his finding at a scientific meeting, he spoke of it as an x-ray because the symbol x represented the unknown. After his findings were reported and published, fellow scientists honored him by calling the invisible ray the roentgen ray.

Question 38

18. The x-radiation output of the Crookes tube (named after the English chemist William Crookes) could be predetermined and accurately controlled. T/F

Answer 38

False. (The x-ray output of the Coolidge tube could be predetermined and accurately controlled.)

Question 39

19. Early scientists and researchers working in the field of radiography were not aware that continued exposure produced accumulations of radiation effects in the body. T/F

Answer 39

True. (Because x-rays are invisible, scientists and researchers working in the field of radiography were not aware that continued exposure produced accumulations of radiation effects in the body, and therefore could be dangerous to both patient and radiographer.)

Question 40

20. In the early 1900s, it was common practice for the radiographer to help the patient hold the film in place while making the exposure. T/F

Answer 40

True. (When radiography was in its infancy, it was common practice for the dentist or dental assistant to help the patient hold the film in place while making the exposure.)

Question 41

1. Who first determined that x-rays would play a role in dentistry?

Answer 41

Dr. Otto Walkhoff. (held a small photographic plate in his mouth for a 25-minute exposure to demonstrate that radiographs of the teeth could be made.)

Question 42

2. Who is considered to be the first advocate for the science of radiation protection?

Answer 42

Dr. William Herbert Rollins. (was one of the first to alert the profession to the need for radiation hygiene and protection.)

Question 43

3. Who developed the hot cathode ray tube?

Answer 43

William David Coolidge (In 1913, William David Coolidge, working for the General Electric Company, designed the hot cathode tube in which the tube and high-voltage transformer were placed in an oil-filled compartment that acted as a radiation shield and electrical insulator.)

Question 44

4. Which radiograph displays the entire dentition and surrounding structures?

Answer 44

panoramic radiograph (A panoramic radiograph displays a broad area of the mandible and maxilla on a single image receptor.)

Question 45

5. What is the technique of choice for intraoral radiography?

Answer 45

The paralleling technique (is the technique of choice because it is less complicated and more consistently produces better radiographs than the bisecting technique.)

Question 46

6. In dental digital imaging systems, what replaces film?

Answer 46

Sensors (are comparable to film in dimensions and nearly comparable in radiographic quality.)

Question 47

7. What medical imaging modality records a selected plane of tissues?

Answer 47

computed tomography (CT) scan (A computed tomography (CT) scan images a single selected plane of tissues.)

Question 48

8. What is the name of the device that functions to direct the x-ray beam toward the patient?

Answer 48

position indicating device (PID) | (is used to direct the x-ray beam.)

Question 49

9. What is the purpose of studying the history of radiography and dental radiography?

Answer 49

Through familiarity with the evolution of concepts and theories, investigators gain knowledge about current practices and appreciate future advancements.

Question 50

1. Each of the following is a form of energy EXCEPT one. Which one is the EXCEPTION? a. Heat b. Water c. Light d. X-radiation

Answer 50

b. Water (is a form of matter. Heat, light, electricity, and x-radiation are forms of energy)

Question 51

2. What is the maximum number of electron shells (energy levels) an atom can have? a. 1 b. 3 c. 5 d. 7

Answer 51

d. 7 (The innermost shell is the K shell, followed by the L shell, and so on, up to a maximum of seven shells.)

Question 52

3. Each of the following is a form of ionizing radiation EXCEPT one. Which one is the EXCEPTION? a. Cosmic rays b. X-rays c. Radio waves d. Gamma rays

Answer 52

c. Radio waves (Only radiation that produces ions is termed ionizing radiation.)

Question 53

4. Each of the following statements about electromagnetic radiations is true EXCEPT one. Which one is the EXCEPTION? a. They have a negative electrical charge. b. They have no mass. c. They pass through space as particles and in a wave-like motion. d. They have no weight.

Answer 53

a. They have a negative electrical charge. (Electromagnetic radiations have no electrical charge.)

Question 54

5. Which of the following statements about x-rays is NOT true? a. They travel at the speed of light. b. They are invisible. c. They have no mass. d. They travel in convergent lines.

Answer 54

d. They travel in convergent lines. | (X-rays travel in divergent lines.)

Question 55

6. Which one of these is NOT a Système International (SI) unit of measurement? a. Sievert b. Roentgen c. Coulombs per kilogram d. Gray

Answer 55

b. Roentgen (Roentgen is a traditional unit of measurement.)

Question 56

7. The Système International unit for measuring absorbed dose is the a. Gray b. Sievert c. Rad d. Rem

Answer 56

a. Gray (While the rad is the unit for measuring absorbed dose in traditional units, the gray is the unit used by the SI system.)

Question 57

8. The greatest exposure to ionizing radiation to the population comes from a. Medical x-rays b. Occupational exposure c. Dental x-rays d. Background radiation

Answer 57

d. Background radiation ## Footnote *(Background radiation refers to that radiation which is always present in the environment. The sources of background radiation include cosmic rays from outer space, terrestrial radiations from the earth, and naturally occurring radionuclides which we inadvertently inhale or ingest.)*

Question 58

9. The speed of a wave is its a. Wavelength b. Velocity c. Frequency d. Photon

Answer 58

b. Velocity ## Footnote *(Velocity is a measure of the speed of travel.)*

Question 59

10. The majority of x-rays produced by dental x-ray machines are formed by: a. Characteristic radiation b. Radionuclide decay c. Bremsstrahlung radiation d. Coherent scattering

Answer 59

c. Bremsstrahlung radiation ## Footnote *(The majority of x-rays produced by dental x-ray machines are formed by general/bremsstrahlung radiation which is produced when electrons are accelerated across the tube head and abruptly stop against the tungsten target.)*

Question 60

11. Radiation is best described as a: a. substance that occupies space. b. resistor of heat. c. type of electricity. d. movement of energy.

Answer 60

d. movement of energy. ## Footnote *Radiation is defined as the emission and movement ofenergy through space in the form of electromagnetic radiation (x- and gamma rays) or particulate radiation (alpha andbeta particles).*

Question 61

12. The smallest particle of a substance that still retains the properties of that substance is a/an: a. atom. b. electron. c. neutron. d. molecule.

Answer 61

d. molecule. ## Footnote *A molecule is the smallest particle of a substance that retains the properties of that substance.*

Question 62

13. The emission and movement of electromagnetic or particulate energy through space is known as: a. ionization. b. radiation. c. radioactivity. d. the formation of ion pairs.

Answer 62

b. radiation. ## Footnote *Radiation is defined as the emission and movement of energ through space in the form of electromagnetic radiation (x- and gamma rays) or particulate radiation (alpha and beta particles).*

Question 63

14. The measure of the number of waves that pass a given point per unit of time is known as the: a. angstrom unit. b. wavelength. c. frequency. d. velocity.

Answer 63

c. frequency. ## Footnote *(Frequency is a measure of the number of waves that pass a given point per unit of time.)*

Question 64

15. When x-rays pass through matter, which interaction results in x-rays being scattered in all directions? a. The coherent effect b. The photoelectric effect c. The Compton effect

Answer 64

c. The Compton effect ## Footnote *The Compton effect causes x-rays to be scattered in all directions.*

Question 65

16. The amount of energy deposited in the teeth or soft tissue by any type of radiation is called the: a. exposure amount. b. absorbed dose. c. dose equivalent. d. background radiation.

Answer 65

b. absorbed dose. ## Footnote Absorbed dose is the traditional unit of measure referring to the amount of energy deposited in tissues by any type of radiation.

Question 66

17. The units used to measure the dose equivalent of radiation is the: a. Gray (Gy). b. Sieverts (Sv). c. Coulombs per kilogram (C/kg). d. Roentgens (R).

Answer 66

b. Sieverts (Sv) ## Footnote *Sievert is the Système International unit for measuring dose equivalent*.

Question 67

18. The sievert and rem are units of measurement for: a. the radiation exposure in the air. b. the amount of energy absorbed by tissues. c. the comparison of biological effects. d. All of the above.

Answer 67

c. the comparison of biological effects. ## Footnote *The sievert is the Système International unit and the rem is the traditional unit of measurement for the comparison of biological effects.*

Question 68

19. A weighting (qualifying) factor is used to determine which of the following? a. coulombs per kilogram b. sievert c. roentgen d. gray

Answer 68

b. sievert ## Footnote *“Dose equivalent” is defined as the product of the absorbed dose multiplied by a biological-effect qualifying or weighting factor. The Système International unit for measuring the dose equivalent is the sievert (Sv)*

Question 69

20. The wavelength determines the energy and penetrating power of the radiation. The longer the wavelength, the higher the energy of the radiation. a. The first statement is true. The second statement is false. b. The first statement is false. The second statement is true. c. Both statements are true. d. Both statements are false.

Answer 69

a. The first statement is true. The second statement is false. ## Footnote *Wavelength is the distance between two similar points on two successive waves. The shorter the wavelength, the more penetrating the radiation.*

Question 70

1. Matter is defined as the ability to do work and overcome resistance. T/F

Answer 70

False. ## Footnote *Energy is the ability to do work and overcome resistance. Energy is produced whenever the state of matter is altered.*

Question 71

2. An atom is the smallest part of an element that still retains properties of that element. T/F

Answer 71

True. ## Footnote *If an atom is split, the resulting particles do not retain the full properties of the element.*

Question 72

3. Electrons have a positive charge. T/F

Answer 72

False. ## Footnote Electrons have a negative charge and are constantly orbiting the nucleus. Protons are the component of an atom that have a positive charge.

Question 73

4. The inner-most electron shell in an atom is the K shell. T/F

Answer 73

True. ## Footnote *There may be as many as seven shells in an atom. The innermost level is the K shell, followed by the L shell, and so on.*

Question 74

5. Dental x-rays do not involve the use of radioactivity. T/F

Answer 74

True. ## Footnote *Dental x-rays involve the use of electromagnetic radiation and not unstable radioactive isotopes.*

Question 75

6. X-rays travel at the speed of sound. T/F

Answer 75

False. ## Footnote *X-rays travel at the speed of light (186,000 miles per second).*

Question 76

7. Wavelength and frequency are directly related.

Answer 76

False. ## Footnote *Wavelength and frequency are inversely related. When the wavelength is long, the frequency is low. When the wavelength is short, the frequency is high.*

Question 77

8. X-rays make the materials they pass through radioactive.

Answer 77

False. ## Footnote *Dental x-rays have no effect on the atoms they interact with, so the irradiated materials are not made radioactive.*

Question 78

9. The photoelectric effect is an all-or-nothing energy loss.

Answer 78

True. ## Footnote *When an x-ray imparts all of its energy to an orbital electron of an atom, the x-ray vanishes.*

Question 79

10. The Compton effect causes x-rays to be scattered in all directions. T/F

Answer 79

True. ## Footnote *Part of the energy of a dental x-ray is transferred to an orbital electron and a new, weaker x-ray is formed that scatters in a different direction, possibly even a direction opposite to the original x-ray.*

Question 80

11. The number of electrons in the nucleus of an element determines its atomic number. T/F

Answer 80

False. ## Footnote *The number of protons in the nucleus of an element determines its atomic number.*

Question 81

12. Background radiation includes cosmic rays from outer space, naturally occurring radiation from the earth, and radiation from radioactive materials. T/F

Answer 81

True. ## Footnote *Background radiation is defined as ionizing radiation that is always present in our environment and includes cosmic rays from outer space, naturally occurring radiation from the earth, and radiation from radioactive materials.*

Question 82

13. Kinetic energy is the internal energy within the atom that holds its components together. T/F

Answer 82

False. ## Footnote *Binding energy is the internal energy within the atom that holds its components together.*

Question 83

14. The total number of protons in the nucleus of an atom determines the atomic number. T/F

Answer 83

True. ## Footnote *The number of protons in the nucleus of an element determines its atomic number.*

Question 84

15. Energy that travels in a different direction than that of the original x-ray is collectively called “secondary radiation.” T/F

Answer 84

True. ## Footnote *Secondary radiation is radiation that travels in a direction opposite that of the original x-ray.*

Question 85

16. The majority of x-rays produced by dental x-ray machines are formed by general (bremsstrahlung) radiation. T/F

Answer 85

True. ## Footnote *The majority of x-rays produced by dental x-ray machines are formed by general/bremsstrahlung radiation.*

Question 86

17. The electromagnetic spectrum arranges energy types by decay rates. T/f

Answer 86

False. ## Footnote *The electromagnetic spectrum arranges energy types by wavelengths.*

Question 87

18. X-rays of high energy and extremely short wavelengths are classified as hard radiation. T/F

Answer 87

True. ## Footnote *Hard radiation refers to x-radiation with extremely short wavelengths indicative of high energy.*

Question 88

19. Ionizing radiation is energy that is capable of producing ions. T/F

Answer 88

True. ## Footnote *Any radiation that produces ions is called “ionizing radiation.”*

Question 89

20. Electromagnetic radiation is propelled through space as both a particle and a wave. T/F

Answer 89

True. ## Footnote *Electromagnetic radiations display two seemingly contradictory properties. It is believed to move through space as both a particle and a wave.*

Question 90

1. What is defined as anything that occupies space and has mass?

Answer 90

Matter. ## Footnote *The world consists of matter and energy. Matter makes up anything we can see, touch, and recognize.*

Question 91

2. What are the positively charged particles in the nucleus of an atom called?

Answer 91

Protons. ## Footnote *Positively charged protons and neutral neutrons make up the nucleus of atoms.*

Question 92

3. What is the term for atoms that have gained or lost electrons and electrical neutrality?

Answer 92

Ions. ## Footnote *The number of protons (positive charges) in an atom normally equals the number of electrons (negative charges). When an electron is removed from a neutral atom, it loses electrical neutrality and becomes an ion.*

Question 93

4. What is the name of the process in which unstable elements undergo spontaneous decay in order to become stable?

Answer 93

Radioactivity. ## Footnote *Unstable, radioactive isotopes try to regain nuclear stability through the release of energy.*

Question 94

5. What is the term for bundles of energy that travel through space at the speed of light?

Answer 94

Photons. ## Footnote *The particle (or quantum) theory assumes that electromagnetic radiations are particles or quanta. These particles are called “photons.”*

Question 95

6. What is the speed of a wave called?

Answer 95

Velocity. ## Footnote *“Velocity” is the term for the speed of a wave of electromagnetic energy*

Question 96

7. When radiation has great penetrating power it is called what?

Answer 96

Hard radiation. ## Footnote *Useful wavelengths in diagnostic dental radiography range from 0.1 to 0.5 Angstrom and are called “hard radiation” because they have sufficient penetrating power to expose dental radiographs.*

Question 97

8. Should you wait 30 seconds after making an exposure before entering the room?

Answer 97

No. ## Footnote *X-rays travel at the speed of light and cease to exit the tube head within a fraction of a second after releasing the exposure button.*

Question 98

9. People living on the Colorado plateau receive a higher dose of what type of radiation than people living in Philadelphia?

Answer 98

background. ## Footnote *Those living on the Colorado plateau receive additional background radiation due to the increased cosmic radiation at the higher altitude and enhanced terrestrial radiation from higher concentrations of radionuclides like uranium in the soil.*

Question 99

10. One gray equals how many rads?

Answer 99

100. ## Footnote *The gray is the unit in the SI system that is replacing the rad unit in the traditional system. They both measure absorbed dose.*

Question 100

he x-ray machine component that allows an operator to position the tube head is called the: A. Timer cord B. Control panel C. Dead-man switch D. Extension arm

Answer 100

D. Extension arm

Question 101

Each of the following EXCEPT one may be located on the control panel. Which one is the EXCEPTION? A. mA selector B. kV selector C. Focusing cup D. Line switch

Answer 101

C. Focusing cup

Question 102

o generate a larger quantity of electron available to produce x-rays, increase the: A. mA (milliamperage) B. kV (kilovoltage) C. PID (position indicating device) D. DC (direct current)

Answer 102

A. mA (milliamperage)

Question 103

After depressing the exposure button the radiographer will hear an audible beep sound indicating that the: A. kilovoltage has reached the peak B. x-rays are being generated C. cathode and anode are reversing polarity D. alternating current have been transformed into direct current

Answer 103

B. x-rays are being generated

Question 104

Which of the following will step up or step down the current coming into an x-ray machine? A. Radiator B. Collimator C. Transformer D. Filter

Answer 104

C. Transformer

Question 105

What term described the electrical pressure (difference in potential) between two electrical charges? A. Amperage B. Voltage C. Ionization D. Incandescence

Answer 105

B. Voltage

Question 106

7. What term best describes an x-ray bream that is composed of a variety of energy wavelengths? A. Polychromatic B. Short scale C. Filtered D. Collimated

Answer 106

A. Polychromatic

Question 107

8. Alternating electrical current changes its direction of flow 60 times a second. AC dental x-ray machines are ideally suited for use with exposing digital image receptors. A. The first statement is true. The second statement is false. B. The first statement is false. The second statement is true. C. Both statements are true. D. Both statements are false.

Answer 107

A. The first statement is true. The second statement is false.

Question 108

. A DC dental x-ray machine that is set with a 60 kV would mots likely have an x-ray output of: A. 15kV B. 30kV C. 60kV D. 90kV

Answer 108

C. 60kV

Question 109

List the three conditions that must exist for x-rays to be produced.

Answer 109

1. An available source of free electrons 2. High voltage to impart speed to the electrons 3. A target that is capable of stopping/slowing the electrons

Question 110

Draw and label parts of a dental x-ray tube.

Answer 110

Question 111

he process of heating the cathode wire filament until red hot and electrons boil off is called: A. autotransformation B. focusing C. thermionic emission D. kilovoltage peak--

Answer 111

C. thermionic emission

Question 112

Which of these must be charged negatively during the time that the x-ray tube is operating to produce x-rays? A. Radiator B. Target C. Anode D. Cathode

Answer 112

D. Cathode

Question 113

What term describes the opening in the tube housing that allows the primary beam to exit? A. Yoke B. Port C. Filament D. Focusing cup

Answer 113

B. Port

Question 114

Which of the following removes the low-energy, long-wavelength energy from the beam? A. Filter B. Collimator C. Transformer D. Radiator

Answer 114

A. Filter

Question 115

hat term describes the smallest particle of an element that retains the properties of that element? A. Atom B. Molecule C. Photon D. Isotope

Answer 115

A. Atom

Question 116

Which of these subatomic particle carries a negative electric charge? A. Proton B. Neutron C. Nucleus D. Electron

Answer 116

D. Electron

Question 117

Radiant energy sufficient to remove an electron from its orbital level of an atom is called A. Atomic B. Electronic C. Ionizing D. Ultrasonic

Answer 117

C. Ionizing

Question 118

What term describes the process by which unstable atoms undergo decay in an effort to obtain nuclear stability? A. Absorption B. Radioactivity C. Radiolucent D. Ionization

Answer 118

B. Radioactivity

Question 119

Which of the following is not a property shared by all energies of electromagnetic spectrum? A. Have energy that is measurable and diff B. Travel in pulsating motion at speed of sound C. Have no electrical charge, mass, or weight. D. Emit an electrical field at right angles to the path of travel

Answer 119

B. Travel in pulsating motion at speed of sound

Question 120

What is the distance between 2 similar points on 2 successive waves called? A. Wavelength B. Frequency C. Velocity D. Energy level

Answer 120

A. Wavelength

Question 121

Which of these electromagnetic radiations has the shortest wavelength? A. Radar B. Ultraviolet rays C. Infrared rays D. X-rays

Answer 121

D. X-rays

Question 122

Which of these forms of radiation has the greatest penetrating power? A. visible light B. X-rays C. Sunlamp D. Radio waves

Answer 122

B. X-rays

Question 123

Which of these forms of radiation is least capable of causing ionization of body tissue cells? A. Cosmic rays B. Gamma rays C. X-rays D. Infrared light

Answer 123

D. Infrared light

Question 124

Radiation produced when high-speed electrons are stopped or slowed down by the tungsten atoms of the dental x-ray tube is called A. general/bremsstrahlung. B. characteristic. C. coherent D. Compton

Answer 124

A. general/bremsstrahlung.

Question 125

X-rays generated for the purpose of making a radiographic image are described as A. scatter radiation B. tertiary radiation C. primary radiation D. secondary radiation

Answer 125

C. primary radiation

Question 126

What is the most likely result when dental x-rays interact with matter? A. No interaction B. Photoelectric effect C. Coherent scattering D. Compton scattering

Answer 126

D. Compton scattering

Question 127

Which of these terms is the unit used to measure radiation exposure? A. angstrom (A) B. Coulombs per kg (roentgen) C. sievert (rem) D. gray (rad)

Answer 127

B. Coulombs per kg (roentgen)

Question 128

The SI unit that has replaced the traditional unit rem is A. coulomb/kilogram. B.. gray. C. rad. D. sievert.

Answer 128

D. sievert.

Question 129

Diagnostic tests used in medical and dental health care that employ ionizing radiations account for what approximate percentage of the overall total exposure to the U.S. population? A. 8 percent B. 28 percent C. 48 percent D. 88 percent

Answer 129

C. 48 percent

Question 130

What is the average annual amount of background radiation to which the U.S. population is exposed? A. 2.1 mSV B. 3.1 mSV C. 4.1 mSV D. 6.1 mSV

Answer 130

B. 3.1 mSVlist three

Question 131

List three sources of background radiation

Answer 131

1. Cosmic radiations from outer space. 2. Terrestrial radiations from the earth and its environments, including radon gas. 3. Background radiations from naturally ocurring radionuclides that are deposited in our bodies by inhalation and ingestion.

Question 132

The study of x-radiation a) radiology b) radiography c) roentegen ray d) Radiograph e) x-ray

Answer 132

a) radiology

Question 133

image or picture produced by x-rays a) radiology b) radiography c) roentegen ray d) Radiograph e) x-ray

Answer 133

d) Radiograph

Question 134

Older term given to x-radiation for its discover a) radiology b) radiography c) roentegen ray d) Radiograph e) x-ray

Answer 134

c) roentegen ray

Question 135

Original term for roentgen applied to the invisible ray he discovered a) radiology b) radiography c) roentegen ray d) Radiograph e) x-ray

Answer 135

e) x-ray

Question 136

The making of radiographs by exposing and processing x-ray film a) radiology b) radiography c) roentegen ray d) Radiograph e) x-ray

Answer 136

b) radiography

Question 137

who discovered the xray A. C. Edmund Kells B. Howard Riley Raper C. Franklin McCormack D. Wilhelm Conrad Roentgen

Answer 137

D. Wilhelm Conrad Roentgen

Question 138

when were xrays discovered

Answer 138

1895

Question 139

who is believed to have exposed the prototype of the first dental xray film

Answer 139

Otto Walkhoff

Question 140

Who is considered by many to be the first advocate for the science of radiation protection

Answer 140

william herbert rollins

Question 141

RUE or FALSE:Dental xray machines replaced the original pointed conewith an open cylinder PID to reduce the size of the xray beam and reduce the radiation dose to the patient

Answer 141

true statement

Question 142

who is given credit for suggesting the bisecting technique

Answer 142

cieszynski

Question 143

who is given credit for developing the paralleling technique

Answer 143

franklin mccormack

Question 144

which imaging modality does not require the use of ionizing radiation

Answer 144

magnetic resonance imaging (MRI)

Question 145

Term used to refer to the silver halide combinations present in the film emulsion. a. Crystal b. Density c. Definition d. Distortion e. Contrast

Answer 145

a. Crystal

Question 146

Overall darkening or blackening of the radiographic image. a. Crystal b. Density c. Definition d. Distortion e. Contrast

Answer 146

b. Density

Question 147

Sharpness and clarity of the outline of the structures in a radiographic image. a. Crystal b. Density c. Definition d. Distortion e. Contrast

Answer 147

c. Definition

Question 148

Variation in the true size and shape of the object recorded on the radiograph. a. Crystal b. Density c. Definition d. Distortion e. Contrast

Answer 148

d. Distortion

Question 149

The visual differences between shades ranging from black to white in adjacent areas of the radiographic film. a. Crystal b. Density c. Definition d. Distortion e. Contrast

Answer 149

e. Contrast

Question 150

Positive electrode in the x-ray tube. a. Anode b. Amperage c. Alternating current d. Electron cloud e. Filament

Answer 150

a. Anode

Question 151

The strength of an electric current measured in amperes. a. Anode b. Amperage c. Alternating current d. Electron cloud e. Filament

Answer 151

b. Amperage

Question 152

The flow of electrons in one direction, and then the opposite direction. a. Anode b. Amperage c. Alternating current d. Electron cloud e. Filament

Answer 152

c. Alternating current

Question 153

A mass of free electrons moving around the filament wire of the cathode when it is heated to incandescence. a. Anode b. Amperage c. Alternating current d. Electron cloud e. Filament

Answer 153

d. Electron cloud

Question 154

A spiral tungsten coil in the focusing cup of the cathode of the x-ray tube. a. Anode b. Amperage c. Alternating current d. Electron cloud e. Filament

Answer 154

e. Filament

Question 155

A unit of measurement that describes wavelengths of certain high-frequency radiation. a. Angstrom b. Absorption c. Alpha particle d. Atom e. Soft radiation

Answer 155

a. Angstrom

Question 156

A process through which radiation imparts some or all of its energy to any material through which it passes. a. Angstrom b. Absorption c. Alpha particle d. Atom e. Soft radiation

Answer 156

b. Absorption

Question 157

A common form of particulate (corpuscular) radiation. ## Footnote a. Angstrom b. Absorption c. Alpha particle d. Atom e. Soft radiation

Answer 157

c. Alpha particle

Question 158

The smallest particle of an element that still has the properties of that element. a. Angstrom b. Absorption c. Alpha particle d. Atom e. Soft radiation

Answer 158

d. Atom

Question 159

Long wavelengths of x-rays. a. Angstrom b. Absorption c. Alpha particle d. Atom e. Soft radiation

Answer 159

e. Soft radiation

Question 160

Older term used to describe the position indicating device (PID) or beam indicating device (BID). a. Cone b. Cone beam computed tomography c. Sensor d. Computer tomography e. Dosage

Answer 160

a. Cone

Question 161

Technique based on CT scanning for obtaining enhanced two- and three-dimensional images, specifically of dental structures. a. Cone b. Cone beam computed tomography c. Sensor d. Computer tomography e. Dosage

Answer 161

b. Cone beam computed tomography

Question 162

An electronic or coated plate that is sensitive to x-rays and replaces film for use in digital imaging. a. Cone b. Cone beam computed tomography c. Sensor d. Computer tomography e. Dosage

Answer 162

c. Sensor

Question 163

Radiographic imaging technique that images an isolated slice of tissue while blurring out other structures. a. Cone b. Cone beam computed tomography c. Sensor d. Computer tomography (CT) e. Dosage

Answer 163

d. Computer tomography (CT)

Question 164

Radiation absorbed in a specified area of the body measured in grays (Gy) or rads. a. Cone b. Cone beam computed tomography c. Sensor d. Computer tomography (CT) e. Dosage

Answer 164

e. Dosage

Question 165

1. Soft tissues and air spaces will appear _______________ on a radiograph.

Answer 165

radiolucent, black, dark

Question 166

2. The degree of blackness on a dental radiograph is referred to as \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 166

density

Question 167

3. Movement of the patient, the image receptor, or the tube head and PID results in \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 167

loss of image sharpness, blur, blurriness

Question 168

. _______________ results when the image receptor is not parallel to the object.

Answer 168

Distortion

Question 169

5. When mA or kV is increased, the exposure time needs to be _______________ in order to maintain optimal image density.

Answer 169

decreased

Question 170

In addition to seconds, exposure time may be indicated by \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 170

impulses

Question 171

The exposure button must be located in an area of protection or at least _______________ from the source of radiation.

Answer 171

6 feet

Question 172

A _______________ transformer decreases the voltage.

Answer 172

step-down

Question 173

High-velocity electrons are converted into 99 percent heat and 1 percent \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 173

x-rays

Question 174

After x-rays exit the port, a lead _______________ restricts the x-ray beam into the desired size and shape.

Answer 174

collimator

Question 175

Electron shells are also called \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 175

energy levels

Question 176

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ are bundles of energy that travel through space at the speed of light.

Answer 176

Photons

Question 177

All electromagnetic radiation travels at a speed of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 177

186,000 mps or light

Question 178

Dense structures, such as bone and enamel, will appear _______________ on a radiograph.

Answer 178

radiopaque, white, light, clear

Question 179

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ accounts for only a very small portion of the x-rays produced in a dental x-ray machine.

Answer 179

Characteristic radiation

Question 180

Dental professionals use the term __________ because it is more descriptive and easier to pronounce than roentgenograph.

Answer 180

radiograph

Question 181

Older-style, dental x-ray machine cones have been replaced with \_\_\_\_\_\_\_\_\_\_.

Answer 181

PIDs (position indicating devices),

Question 182

Oral __________ is the study of x-rays and the techniques used to produce radiographs.

Answer 182

radiology

Question 183

Direct digital imaging replaces film with a \_\_\_\_\_\_\_\_\_\_.

Answer 183

sensor

Question 184

Early dental x-ray image receptors consisted of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, which were wrapped in black paper and rubber.

Answer 184

glass plates

Question 185

Dentin appears more radiopaque than enamel. True False

Answer 185

False

Question 186

If more light is transmitted through a film, the radiograph is said to have greater density. True False

Answer 186

False

Question 187

If milliamperage or the exposure time is increased, the density of the resultant radiograph will be decreased. True False

Answer 187

False

Question 188

Increasing kV decreases image contrast. True False

Answer 188

True

Question 189

Sharper images are produced with a smaller focal spot. True False

Answer 189

True

Question 190

A long target–object distance reduces penumbra. True False

Answer 190

True

Question 191

A lower contrast image results when scatter radiation is lowered. True False

Answer 191

True

Question 192

A short object–image receptor distance reduces image magnification. True False

Answer 192

True

Question 193

If the milliamperage is increased from 10 mA to 15 mA, the exposure time must also be increased to produce a radiograph of identical density. True False

Answer 193

False

Question 194

When increasing the kV by 15, the exposure time must be multiplied by two to produce a radiographic image of identical density. True False

Answer 194

False

Question 195

Milliamperage determines the amount of x-rays produced. True False

Answer 195

True

Question 196

The kV selector determines the penetrating ability of x-rays produced. True False

Answer 196

True

Question 197

There are 15 impulses in a 1/4 second exposure. True False

Answer 197

True

Question 198

The operator can safely reenter the room during the audible beep made by the dental x-ray machine. True False

Answer 198

False

Question 199

Leaving the dental x-ray machine tube head suspended for long periods of time with the extension arm stretched out can result in a drifting tube head. True False

Answer 199

True

Question 200

Alternating current is ideal for digital imaging. True False

Answer 200

False

Question 201

The source of electrons for x-ray production is supplied by the cathode. True False

Answer 201

True

Question 202

The larger the focal spot, the sharper the radiographic image. True False

Answer 202

False

Question 203

Copper is the metal used to carry the heat produced during exposure to a radiator outside of the x-ray tube. True False

Answer 203

True

Question 204

The target is set into the copper stem at an angle to direct most of the x-rays toward a window opening in the vacuum. True False

Answer 204

True

Question 205

Energy is produced whenever the state of matter is naturally or artificially altered. True False

Answer 205

True

Question 206

Atoms have the unique ability to retain their properties once they are split. True False

Answer 206

False

Question 207

Wavelength and frequency are inversely related. True False

Answer 207

True

Question 208

Frequency is the measure of the distance between two points on the electromagnetic spectrum. True False

Answer 208

False

Question 209

The longer the wavelength, the more penetrating the radiation. True False

Answer 209

False

Question 210

Soft x-rays are the result of long wavelengths and low frequencies. True False

Answer 210

True

Question 211

Less dense structures, such as the pulp chamber of the tooth, will appear dark gray or black on a radiograph. True False

Answer 211

True

Question 212

The Compton effect causes x-rays to be scattered in all directions. True False

Answer 212

True

Question 213

X-rays cause radioactivity when they pass through structures. True False

Answer 213

False

Question 214

Exposure to radiation does not produce a measurable dose until the radiation is absorbed in the tissues. True False

Answer 214

True

Question 215

This or that: Higher kVp has a Short Scale Contrast or Higher kVp has a Long Scale Contrast

Answer 215

Higher kVp has a Long Scale Contrast

Question 216

This or that: Higher kVp has higher energy or Higher kVp has lower energy

Answer 216

Higher kVp has higher energy

Question 217

The hazards of prolonged exposure to radiation are not completely understood. True False

Answer 217

True

Question 218

X-rays were once used for entertainment purposes at fairgrounds. True False

Answer 218

True

Question 219

Variable, high-kilovoltage dental x-ray machines contributed to dangerous exposure from unnecessary radiation. True False

Answer 219

False

Question 220

This or that: Higher kVp has Less Color or High kVp has More Color

Answer 220

High kVp has More Color

Question 221

Technological developments continue to improve radiation safety by increasing the size of the x-ray beam. True False

Answer 221

False

Question 222

The pointed cone increased the dose of radiation received by the patient True False

Answer 222

True

Question 223

Panoramic dental x-ray machines produce a radiograph of the entire dentition and surrounding structures. True False

Answer 223

True

Question 224

This or that: Higher kVp has shorter wavelengths or Higher kVp has Longer wavelengths

Answer 224

Higher kVp has shorter wavelengths

Question 225

Digital imaging is preferred for periodontal conditions, but dental film is required for accurate caries detection. True False

Answer 225

False

Question 226

This or that: Higher kVp has a higher frequency or Higher kVp has a lower frequency

Answer 226

Higher kVp has a higher frequency

Question 227

The paralleling method is the method of choice for exposing intraoral dental radiographs. True False

Answer 227

True

Question 228

The introduction of a digital sensor for dental radiography has eliminated the use of the bisecting technique. True False

Answer 228

False

Question 229

This or that: Higher kVp has more shades of Gray or Higher kVp has Fewer shades of Gray

Answer 229

Higher kVp has more shades of Gray

Question 230

The incorporation of first transistors and computer technology has permitted significant radiation reduction in modern x-ray machines. True False

Answer 230

True

Question 231

This or That: Higher kVp will have increased Density (darker film) or Higher kVp will have decreased Density (Lighter film)

Answer 231

Higher kVp will have increased Density (darker film)