Final Flashcards
The smaller the silver halide crystals in the emulsion of an intraoral film, the faster the film speed.
Faster film speed reduces radiation exposure to the patient.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
D. The first statement is false, and the second statement is true.
Which of the following statements BEST describes the anomaly in the image shown below?
A Foreshortening of the root, vertical angle too great
B Foreshortening of the root, vertical angle not enough
C Incomplete apical development of the root
D Internal resorption of the root
E External resorption of the root
E. External resorption of the root
A periapical (PA) image is needed on the maxillary left premolar area. The patient presents with a large maxillary torus. Using the paralleling, or right-angle, technique, the image receptor film or sensor is to be placed
A distal to the maxillary premolar area.
B mesial to the maxillary premolar area.
C as close to the maxillary left premolar as possible.
D as far from the maxillary left premolar as possible.
D. as far from the maxillary left premolar as possible.
A periapical image of the maxillary right molar area is needed, but patient has a shallow palate, and the first image taken misses the apices of the teeth. To correct this error, using the paralleling technique, an acceptable image can be obtained by moving the PID in a:
A 20-degree difference in the horizontal angulation toward the mesial surfaces.
B 20-degree difference in the horizontal angulation toward the distal surfaces.
C positive 20-degree difference in the vertical angulation.
D negative 20-degree difference in the vertical angulation.
E direction in which the central ray is perpendicular to the image receptor.
C. +20-degree difference in the vertical angulation.
A radiographic image will have increased density if the operator:
A increases the kVp.
B decreases the kVp.
C decreases the milliampere (mA).
D increases the distance of the x-ray source to the image receptor.
A. increases the kVp.
Absorption:
Process of transferring energy of x-rays to atoms of material through which the x-ray beam passes
The beam of x-rays passing through matter is
weakened and gradually disappears.
(tooth absorbs energy = turns white)
According to the SLOB rule, the position of objects can be determined if the tube head is shifted in a mesial direction. The lingual object moves distally, and the buccal object moves mesially.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
B. Both statements are false.
All of the following are examples of radiosensitive cells EXCEPT one.
Which one is the EXCEPTION?
A. Cells with higher metabolism
B Cells with high mitotic activity
C Older, mature cells
D Primitive, nonspecialized cells
C. Older, mature cells
All of the following decrease radiation exposure to the patient EXCEPT one. Which one is the EXCEPTION?
A Thyroid collar
B F-speed film in place of D-speed film
C 8-inch PID in place of 16-inch PID
D Rectangular PID in place of round PID
E Collimator
C. 8-inch PID in place of 16-inch PID
All of the following factors increase image sharpness EXCEPT one. Which one is the EXCEPTION?
A Slower film speed
B Small focal spot
C Decreased penumbra
D Movement
D. Movement
All of the following phrases are consistent with the paralleling technique
EXCEPT one. Which one is the EXCEPTION?
A. A short PID is used.
B. It is the preferred method for taking radiographs.
C. The film is placed parallel to the long axis of the tooth.
D. The central ray is directed perpendicular to the tooth and the image receptor.
E. It produces images with the least magnification and dimensional distortion.
A. A short PID is used.
An x-ray beam has a half-value layer (HVL) of 6 mm. How many millimeters of aluminum are required to reduce the x-ray beam intensity by half?
A 2 mm
B 3 mm
C 6 mm
D 12 mm
C. 6 mm
Characteristic radiation:
(C)
Produced when a high-speed electron from the tube filament collides with an orbiting K-shell electron of the tungsten target.
Coherent scattering:
(B)
Incoming x-ray photon interacts with the electron by causing the electron to vibrate at the same frequency as the incoming x-ray photon.
Accounts for about 8% of the interactions of matter with the dental x-ray beam
Compton scattering:
Similar to the photoelectric effect
Incoming x-ray photon collides with an orbital electron and ejects it. But, only a part of the x-ray energy is transferred to the electron, and a new, weaker x-ray photon is formed and scattered in a new direction.
Accounts for about 60% of the interactions of matter with the dental x-ray beam.
Cone cutting has occurred on the coronal portion of a mandibular anterior PA image. The operator will correct this error by:
A. moving the image receptor more superiorly.
B moving the image receptor more inferiorly.
C moving the PID to completely cover the image receptor.
D adding more solution to the developer.
E adding more solution to the fixer.
C. moving the PID to completely cover the image receptor.
Considering exposure time during the production of x-rays, how many impulses are equivalent to 1⁄4 second?
A 1
B 6
C 15
D 30
E 240
C. 15
There are 60 impulses in a second, so to calculate impulses, multiply
60 x 1⁄4 second = 15 impulses
Erythema, nausea, diarrhea, hemorrhage, and loss of hair are
signs and symptoms seen with
A. chronic radiation exposure.
B acute radiation exposure.
C stochastic effects of radiation exposure.
D nonstochastic effects of radiation exposure.
E A and C
F B and D
F.
B. acute radiation exposure.
and
D. nonstochastic effects of radiation exposure.
Failing to follow radiation exposure patient guidelines would put a fetus at greatest risk in which trimester?
A First trimester
B Second trimester
C Third trimester
D Risk during all trimesters is equal
E There is no risk
A. First trimester
For each description of a radiograph’s appearance listed, select the most closely linked error. Each answer will only be used once.
Appearance Error
- Clear A. Film was developed in weak developer
- Light B. Film was exposed to white light
- Light film with “tire tracks” C. Film was placed backward
- Fogged D. Film was developed in a dark room with a crack in the safelight cover
- Black E. Film was not exposed to x-rays
- Clear E. Film was not exposed to x-rays
- Light A. Film was developed in weak developer
- Light film with “tire tracks” C. Film was placed backward
- Fogged D. Film was developed in a dark room with a crack in the safelight cover
- Black B. Film was exposed to white light
From the following list, select examples of stochastic effects of radiation exposure. (Select all that apply.)
A. Erythema
B Cancer
C Hair loss
D Genetic mutations
E Decreased fertility
B. Cancer
D. Genetic mutations
From the following list, select the three elements used in the x-ray tube.
A Bromine
B Copper
C Iron
D. molybdenum (focusing cup)
E Nickel
F Silver
G Tungsten
B. Copper
D molybdenum (focusing cup)
G Tungsten
From the following list, select the three statements
associated with digital imaging.
A. Sensors cannot be sterilized.
B A digital image is a two-dimensional representation of a 3-D object.
C Exposure times are 50% to 90% more than in traditional radiography.
D Digital imaging must be wired to function correctly.
E Assembled pictorial information with each gray value is
assigned a digit in binary code.
A. Sensors cannot be sterilized.
B. A digital image is a two-dimensional representation of a 3-D object.
E. Assembled pictorial information with each gray value is assigned a digit in binary code.
General/bremsstrahlung radiation:
Produced when high-speed electrons are stopped or slowed down by the tungsten atoms of the dental x-ray tube.
Identify # 10
X-Rays
Identify # 11
Port
Identify # 12
Oil
Identify # 14
Cathode (-)
Identify #1
Tube head
Identify #13
Copper stem
Identify #2
Low voltage transformer
Identify #3
Primary beam
Identify #4
High voltage transformer
Identify #5
Window
Identify #6
Collimator
Identify #7
Central ray
Identify #8
Filter
Identify #9
PID
Identify the almond-shaped radiolucent area in the image shown.
A Infraorbital foramen
B Nasal cavity
C Median palatal suture
D Maxillary sinus
E Incisive foramen
E. Incisive foramen
Identify the structure to which the arrows are pointing in the image shown.
A Maxillary sinus
B Maxillary tuberosity
C Genial tubercles
D Zygoma
D. Zygoma
In a darkroom, the correct lighting and distance from the working surface should be
A. a 60-watt bulb placed 6 feet away.
B. a 75-watt bulb placed 6 feet away.
C. a 7.5-watt bulb place 6 feet away.
D. a 30-watt bulb placed 8 feet away.
C. a 7.5-watt bulb place 6 feet away.
In a dental x-ray tube, the kinetic energy of electrons is converted to electromagnetic energy by the formation of:
General or bremsstrahlung radiation
German for “braking”
Characteristic radiation
In the molar bitewing image, the error that will occur as a result of the PID positioning will be distal overlap. Distal overlap is corrected by repositioning the horizontal angulation of the PID more mesiodistally.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
D. The first statement is false, and the second statement is true.
In which anomaly is the cementum of two adjacent teeth joined together?
A Concrescence
B Fusion
C Gemination
D Hypercementosis
A. Concrescence
Interaction of X-rays with Matter:
Four possibilities:
- No interaction
- Coherent scattering
- Photoelectric effect
- Compton effect
No interaction:
(A)
X-ray photon can pass through an atom unchanged and no interaction occurs.
In dental radiography, about 9% of the x-rays pass through the patient’s tissues without interaction.
Order the steps for the manual processing of x-ray films.
Match each letter with its proper sequence number.
Sequence Number Steps
- _____ A. Rinsing in water for 30 seconds
- _____ B. Washing in water for 20 minutes
- _____ C. Developing
- _____ D. Fixing
- _____ E. Drying
- Developing
- Rinsing in water for 30 seconds
- Fixing
- Washing in water for 20 minutes
- Drying
Order the steps in the production of x-radiation.
Match each letter with its proper sequence number.
- _____ A. Electrons travel across to the anode when the high voltage circuit is activated.
- _____ B. Thermionic emission occurs.
- _____ C. 110 or 220 line voltage is reduced to 3 to 5 volts.
- _____ D. Kinetic energy is converted to x-ray energy and heat.
- C. 110 or 220 line voltage is reduced to 3 to 5 volts.
- B. Thermionic emission occurs.
- A. Electrons travel across to the anode when the high voltage circuit is activated.
- D. Kinetic energy is converted to x-ray energy and heat.
Photoelectric effect:
Incoming x-ray photon collides with an orbital electron and imparts electromagnetic energy to the electron in the form of kinetic energy causing electron to fly from its orbit, creating an ion pair.
All-or-nothing energy loss
High-speed electron (called a photoelectron)
knocks other electrons from the orbits of other atoms (forming secondary ion pairs) until all its energy is used up.
Accounts for about 30% of the interactions of matter with the dental x-ray beam
Primary radiation:
General and/or characteristic radiation generated at a target inside x-ray tube head
Refers to the useful beam, or those x-rays generated for the
purpose of making a radiographic image
Radiation exposure is not of concern when it occurs in small doses. The cumulative effect of radiation exposure may lead to health problems such as cancer.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
D. The first statement is false, and the second statement is true.
Radiation may damage cells indirectly by damaging the cell nucleus. Direct cellular damage occurs when ionization causes radiolysis of water producing hydrogen peroxide.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
B. Both statements are false.
Radiography provides the most accurate measurements for the assessment of periodontal disease and its progression. This is because radiographs record both historical and current disease activity.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
B. Both statements are false.
From the following list, select two structures that appear radiolucent on a radiographic image.
A Nasal septum
B Lateral or canine fossa
C Anterior nasal spine
D Inferior nasal conchae
E Nutrient canals
B Lateral or canine fossa
E Nutrient canals
Scatter radiation:
Form of secondary radiation
Results when x-rays are deflected in all directions as a result of interaction with matter
Not useful
Can cause unnecessary additional exposure to patient tissues and to the careless operator who does not follow safety protocols
Lead apron + lead wall = no scatter radiation
Secondary radiation:
Formed as a result of primary radiation striking and interacting with matter
Not as penetrating as primary radiation
Not useful in the production of a radiographic image
Can contribute to a lowered contrast, poor quality image
The coronoid process of the mandible appears as a triangular-shaped
radiopacity. This marked prominence of bone found on the anterior ramus of the mandible is not seen on a mandibular periapical radiograph.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
A. Both statements are true.
The device that restricts the size of the x-ray beam is called a/an
A dosimeter.
B aluminum filter.
C collimator.
D focusing cup.
E inherent filtration.
C. collimator.
The error that will occur to the premolar bitewing image as a
result of the PID positioning will be
A. unequal distribution of maxillary and mandibular teeth. There will be more coverage of maxillary teeth and fewer mandibular teeth.
B unequal distribution of maxillary and mandibular teeth. There will be more coverage of mandibular teeth and fewer maxillary teeth.
C distal overlap.
D mesial overlap.
B. unequal distribution of maxillary and mandibular teeth.
There will be more coverage of mandibular teeth and fewer maxillary teeth.
The kVp setting is the only exposure factor that has direct influence on the contrast of a dental radiograph. High kVp settings result in high contrast images.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
C The first statement is true, and the second statement is false.
The mental fossa is visible in which radiographic image?
A Maxillary premolar
B Maxillary canine
C Mandibular central
D Mandibular premolar
C. Mandibular central
The radiographic appearance of the zygomatic process of the maxilla appears as a J-shaped or U-shaped radiopacity located superior to the maxillary first molar region. The visibility of the zygomatic process of the maxilla on the image is a result of utilization of the bisecting technique.
A. Both statements are true.
B. Both statements are false.
C. The first statement is true, and the second statement is false.
D. The first statement is false, and the second statement is true.
C. The first statement is true, and the second statement is false
The tube head is a component of the x-ray machine that helps limit radiation to the patient in all of the following functions EXCEPT one. Which one is the EXCEPTION?
A. Inherent filtration within glass tube, insulating oil, and tube head
B Added aluminum disk filtration
C Production of both long-wavelength and short-wavelength xrays
D Collimation with lead disk placed in the pathway of the x-ray beam
E Rectangular collimated PID
C. Production of both long-wavelength
and
short-wavelength Xrays
The tubehead of the panoramic unit is angled so that the x-ray beam is directed:
A. in a slightly positive vertical angulation.
B in a strong positive vertical angulation.
C in a slightly negative vertical angulation.
D in a strong negative vertical angulation.
E at zero angulation.
C. in a slightly negative vertical angulation.
To maintain the same image density when increasing the mA, which of the following actions should be taken?
A. Increase kVp
B. Decrease exposure time
C Increase film speed
D Decrease distance from source to object
B. Decrease exposure time
To prevent overlapped contacts on periapical and bite-wing images,
A. position the image receptor parallel to the long axis of the tooth.
B. increase vertical angulation.
C. decrease vertical angulation.
D. direct the x-ray beam through the interproximal contacts.
E. place the image receptor to include the correct teeth on the radiograph.
D. direct the x-ray beam through the interproximal contacts.
When an x-ray photon passes through matter, which of the following situations is MOST likely to occur?
A Photoelectric effect
B Compton scatter
C Coherent scatter
D Characteristic radiation
E General or Bremsstrahlung radiation
F No interaction
B. Compton scatter
When taking a premolar bitewing image, which error in the position of the PID is seen in the photograph shown?
A Greater horizontal angulation than required
B Greater positive vertical angulation than required
C Greater negative vertical angulation than required
D The PID is correctly positioned for a premolar bitewing
C. Greater negative vertical angulation than required
Which factor affects contrast?
A. Distance
B kVp
C. Exposure time
D. mA
B. kVp
Which ingredient of the developing solution in the manual processing of x-ray films is alkaline and aids in the softening of the emulsion?
A Potassium bromide
B Potassium alum
C Sodium carbonate
D Sodium sulfite
E Sodium thiosulfate
C. Sodium carbonate
Which mandibular anatomic landmark can be seen as a radiolucent area on a mandibular premolar periapical (PA) image?
A Genial tubercles
B Internal oblique ridge
C Mental foramen
D Lingual foramen
E Mental ridge
C. Mental foramen
Which of the following BEST describes the process of heating the cathode wire until it is red hot and “boiling off” of electrons?
A Cathode ray
B Beta-particles
C Thermionic emission
D Recoil electron
E Rectification
C. Thermionic emission
Which of the following BEST describes the purpose of the lead foil contained within a radiograph film packet?
A Shield the film from backscattered radiation
B Protect the film from light
C Protect the oral tissues and teeth from excess radiation
D Reduce the amount of radiation received by the patient
A. Shield the film from backscattered radiation
Which of the following concepts are examples of the ALARA concept?
(Select all that apply.)
A Compliance with maximum permissible dose of radiation for the occupationally exposed worker
B Use of evidence-based selection criteria for radiography for patient needs
C Routinely scheduled radiography based on office protocol
D Use of “D” speed film
E Use of film holders
F Shielding with lead thyroid collar and apron
A. Compliance with maximum permissible dose of radiation for the occupationally exposed worker
B. Use of evidence-based selection criteria for radiography for patient needs
E. Use of film holders
F. Shielding with lead thyroid collar and apron
Which of the following is (are) the maximum permissible dose (MPD) for a dental hygienist? (Select all that apply)
A. 0.5 rems a year
B 5 rems a year
C 50 rems a year
D 50 mSv
E 5 mSv
B. 5 rems a year
D. 50 mSv
Which of the following is the receptor that captures computerized images as discrete units of information?
A Sensor
B Film
C Pixel
D Bit-depth image
A. Sensor
Which of the following is the unit used to measure radiation exposure?
A Gray (Gy)
B Radiation absorbed dose (rad)
C Roentgen (R)
Roentgen equivalent in man (rem)
E Sievert (Sv)
C. Roentgen (R)
In the newer SI system (International System of Units), there is
no unit for exposure that is equivalent to the roentgen.
Which of the following techniques would be required to correct a nondiagnostic bitewing radiograph with overlapped interproximal contacts?
A. Increasing the vertical angulation of the PID
B Decreasing the vertical angulation of the PID
C Changing the horizontal angulation of the PID
D Increasing the kVp
C. Changing the horizontal angulation of the PID
Which of the following terms refers to the majority of scatter radiation
produced in dental imaging?
A Coherent scatter
B Compton scatter
C Primary scatter
D Secondary scatter
B. Compton scatter
Which radiolucent landmark is visible on a maxillary posterior periapical image?
A Genial tubercles
B Mandibular foreman
C Zygoma
D Maxillary sinus
D Maxillary sinus
Which statement BEST describes a principle of radiographic image magnification?
A. Greater target–receptor distance increases greater image magnification.
B. Less target–receptor distance reduces image magnification.
C. Greater target–receptor distance reduces image magnification.
D. Target–receptor distance does not affect magnification.
C. Greater target–receptor distance reduces image magnification.
Which statement BEST describes changes to the atom during the
ionizing process?
A. The atom gains an electron and will have a negative charge.
B The atom gains an electron and will have a positive charge.
C The atom loses an electron and will have a negative charge.
D The atom loses an electron and will have a positive charge.
D. The atom loses an electron and will have a positive charge.
Which statement BEST describes the kVp rule?
A. When the kVp is decreased by half, the exposure time is increased by 15.
B. When the kVp is decreased by 15, the exposure time is decreased by half.
C. When the kVp is doubled, the exposure time is decreased by half.
D. When the kVp is increased by 15, the exposure time is decreased by half.
D. When the kVp is increased by 15, the exposure time is decreased by half.
Which statement BEST describes the relationship of the image receptor and the tooth in the paralleling technique?
A. The image receptor is parallel to the long axis of the tooth.
B. The image receptor is slightly angled toward the long axis of the tooth.
C. The central ray of the x-ray beam is directed perpendicular to the receptor and the long axis of the tooth.
D. Both A and C
E. Both B and C
A. The image receptor is parallel to the long axis of the tooth.
and
C. The central ray of the x-ray beam is directed perpendicular to the receptor and the long axis of the tooth.
You wish to compare your patient’s current images with images that were taken 2 years ago. The images from 2 years ago have a yellowish-brown color. Which of the following is the cause of the yellow-brown stains?
A Temperature of the water bath is colder than the developer temperature
B Insufficient fixing
C High developer temperature
D Prolonged rinsing
B. Insufficient fixing
A radiograph that has many shades of grade is considered to have
A high density.
B low density.
C high contrast.
D low contrast.
D. low contrast.
All of the following are descriptions of a ghost image on a panoramic image EXCEPT one. Which one is the EXCEPTION?
A. It is a similar sharpness as the original artifact.
B It is a similar shape to the original artifact.
C It is on the opposite side of the original artifact.
D It is located higher than the original artifact.
E It is larger than the original artifact.
A. It is a similar sharpness as the original artifact.
All of the following structures could be seen on a maxillary molar periapical image EXCEPT one. Which one is the EXCEPTION?
A Coronoid process of the mandible
B Mandibular condyle
C Maxillary tuberosity
D Hamulus
E Floor of the maxillary sinus
B. Mandibular condyle
An impulse is equal to
A. 1 second.
B. 1⁄6 of a second.
C. 1/60 of a second.
D. 1/600 of a second.
C. 1/60 of a second.
Identify the radiolucent area indicated in the radiograph shown.
A Abscess
B Maxillary sinus
C Nasal fossa
D Nasal septum
B. Maxillary sinus
In the formation of x-radiation, electrons that strike the nucleus of a tungsten atom produce which type of x-ray?
A Low-energy
B High-energy
C Both high-energy and low-energy
B. High-energy
Order each tissue in order of radiosensitivity, from most sensitive to least sensitive. Match each letter with its proper sequence number.
- _____ A. Skin
- _____ B. Oral mucosal epithelium
- _____ C. Nervous tissue
- _____ D. Reproductive tissue
- _____ E. Lymphatic tissue and bone marrow
- _____ F. Mature bone and cartilage
- Reproductive tissue
- Lymphatic tissue and bone marrow
- Oral mucosal epithelium
- Skin
- Mature bone and cartilage
- Nervous tissue
The indirect theory of radiation injury suggests that cell damage occurs when ionizing radiation hits critical areas within the cell.
The direct theory of radiation injury suggests that x-ray photons are absorbed within the cell and cause the formation of toxins that in turn damage the cell.
A. Both statements are true.
B Both statements are false.
C The first statement is true, and the second statement is false.
D The first statement is false, and the second statement is true.
B. Both statements are false.
The penetrating quality of the x-ray beam is controlled by the
A film speed.
B exposure time.
C source-to-film distance.
D wavelength.
D. wavelength.
Which of the following describes the appearance of a carious lesion on the buccal or lingual surface of a molar on a dental image?
A Triangular, radiolucent
B Triangular, radiopaque
C Circular, radiolucent
D Circular, radiopaque
C. Circular,
radiolucent
Which structure appears as a radiopaque line surrounding the root of the tooth?
A Trabecular bone
B Cancellous bone
C Lamina dura
D Periodontal ligament space
E Pulp
C. Lamina dura
Which structure or material will appear the MOST radiopaque on a dental image?
A Airspace
B Amalgam restoration
C Periodontal ligament space
D Composite restoration
E Pulp
B. Amalgam restoration
Identify # 15
Focusing cup
Identify # 16
Anode (+)
Identify # 17
Electron cloud
Identify # 18
Filament
Identify # 19
Glass envelope
Identify # 20
Radiator
Identify # 21
Tungsten target
Identify # 22
Vacuum
