Dental Radiology

Quizzes #1,3,4,5,6

all cells of the body with the exception of reproductive cells are called

1. genetic

2. somatice

3. glandular

4. marrow

somatic

the amount of radiation exposed or administered during a given period of time is the

1. roentgen

2. dose rate

3. dose

4. radioactive index

dose rate

which of the following tissues is the most sensitive to x rays

1. blood forming tissue

2. muscle

3. skin

4. nerve

blood forming tissue

decreasing the mAs and increasing the kVp

1. increases the average wavelength

2. lowers the skin dose

3. decreases the exit dose

4. all of the above

lowers the skin dose

which of the following x rays are most apt to be absorbed by the skin

1. central x rays

2. filtered x rays

3. long wavelength x rays

4. short wavelength x rays

long wavelength x rays

the latent period related to radiation biology is that period between

1. exposure of the film and development of the images

2. exposure to x radiation and the appearance of clinical symptoms

3. the period of film developing and film fixing

4. initial radiation exposure and subsequent radiation doses

exposure to x radiation and the appearance of clinical symptoms

the primary method by which x rays damage biological tissues is through

1. heat

2. ionization

3. dose rate

4. none of the above

ionization

the earliest visible clinical sign of skin exposure to radiation is manifested as

1. alopecia

2. erythema

3. keratosis

4. ulceration of the skin

erythema

the recommended collimation of the radiation beam at the patient’s skin surface is

1. 1.5 in

2. 2.75 in

3. 3.75 in

4. 4.25 in

2.75 in

the most effective method of the following reducing radiation exposure to the patient and operator is

1. using a faster film

2. using a film holder

3. reducing developing time

4. reducing the kilovoltage

using a faster film

in normal dental diagnostic procedures, the principle hazard to the operator is produced by

1. gamma radiation

2. ultraviolet radiation

3. secondary radiation

4. primary radiation

secondary radiation

which of the following is least effective in reducing patient radiation dose

1. fast film

2. higher kilovoltage

3. proper collimation

4. increased filtration

higher kilovoltage

the operator should not hold the

1. film during exposure

2. tube during exposure

3. patient during exposure

4. none of these

none of these

lead aprons are used

1. only on pregnant women

2. to reassure patients

3. to reduce scatter radiation to the film

4. on all patients

on all patients

x ray filters are usually made of

1. copper

2. lead

3. aluminum

4. stainless steel

aluminum

which of the following is a major factor in reducing operator exposure during dental radiographic procedures

1. use high kilovoltage tech because shorter exposure time is required

2. use low kilovoltage tech because photons produced with these tech are not as penetrating as high voltage photons

3. stand at least 6 feet from the tube head and avoid the primary beam

4. have the patient wear a lead apron

stand at least 6 ft from the tube head and avoid the primary beam

the amount of tissue damage following irradiation depends on

1. dose rate and intensity

2. area or volume of tissue irradiated

3. intensity of the exposure (chronic or acute)

4. all of the above

all of the above

a film badge

1. is affected by ionizing radiation

2. is affected by other forms of radiant energy

3. should be worn by all occupationally exposed persons

4. is used to identify x ray films

1. 1 2 3

2. 1 and 3

3. 2 and 4

4. 4 only

5. all are correct

1 2 3

which of the following is are example s of somatic cells

1. blood

2. chromosomes

3. nerve

4. genes

1. 1 2 3

2. 1 and 3

3. 2 and 4

4. 4 only

5. all are correct

1 and 3

the operator must stand behind a protective barrier to assure protection from

1. scatter radiation

2. secondary radiation

3. primary beam

4. electrical beam

1. 1 2 3

2. 1 and 3

3. 2 and 4

4. 4 only

5. all are correct

1 2 3

genetic mutations are

1. not passed on to succeeding generations

2. only caused by ionizing radiation

3. passed on to succeeding generations

4. none of these

passed on to succeeding generations

number the following 1-4 most radiosensitive to least radiosensitive

skin and muscle tissue

reproductive cells

glandular tissue young bone and alimentary epithelium

nerve tissue and adult bone

1. reproductive cells

2. glandular tissue young bone and alimentary epithelium

3. nerve tissue and adult bone

4. skin and muscle tissue

the function of the lead diaphragm on the head of the x ray machine is to

1. direct the central ray

2. focus the cathode ray

3. limit the size of the x ray beam

4. reduce the number of long wavelengths

limit the size of the x ray beam

the quality or penetrating power of secondary radiation is

1. more than that of primary radiation

2. less than that of primary radiation

3. the same as that of primary radiation

4. unrelated to that of primary radiation

less than that of primary radiation

the most penetrating x ray s have

1. low freq

2. soft rays

3. long wavelengths

4. short wavelengths

short wavelengths

how do you change from a low contrast film to a high contrast film and still maintain film density

1. decrease the kVp and increase the mAs

2. decrease the kVp and the mAs

3. increase the kVp and decrease the mAs

4. increase the kVp and the mAs

an increase in which of the following factors causes a decrease in the contrast

1. exposure time

2. milliamperage

3. kilovoltage

4. none of the above

the target material in the tube head of the dental x ray unit is

1. copper

2. tungsten

3. lead

4. aluminum

tungsten

x rays are produced at the

1. filter

2. tip of the PID

3. cathode

4. anode

cathode

in standard dental x ray units the quantity of x radiation produced is controlled primarily by

1. exposure time

2. mA

3. kV

4. inherent filtration

mA

the filament circuit in the dental x ray tube

1. requires a step up transformer

2. is observed on a voltmeter

3. provides a cloud of electrons when the cathode is heated sufficiently

4. regulates the speed of the electrons

the transformer used to heat the filament of the x ray tube is a/an

1. autotransformer

2. step up transformer

3. step doen transformer

4. high tension transformer

what percent of electron energy is converted to x radiation at the anode

1. 1%

2. 2%

3. 10%

4. more than 99%

the substance that is most radiopaque is

1. leaded glass

2. plastic

3. wood

4. rubber

leaded glass

if you wished to increase the penetrative quality of x radiation how would you change the exposure factors

1. increase the mA

2. increase the kV

3. increase the mA and the kV

4. increase the mA, kV, and exposure time

increase the kV

which of the following represents the correct progression of energy transformation in the production of x ray photons

1. kinetic energy, electric energy radiation

2. kinetic energy, radiation, electrical energy

3. electrical energy, kinetic energy, radiation

4. electrical energy, radiation, kinetic energy

electrical energy, kinetic energy, radiation

the unit for measuring x ray exposure is called

1. roentgen

2. rad

3. roentgenogram

4. radiogram

roentgen

stray radiation from the dental x ray machine is not harmful because it

1. will not reach the operator if he stands 4 ft away

2. is absent when filtering devices are used

3. is usually in minute amounts

4. none of the above, it can be damaging to all tissues

none of the above, it can be damaging to all tissues

what part of the x ray tubehead conducts the heat produced during the production of x rays away from the tungsten targert?

1. tungsten filament

2. focusing cup

3. oil

4. copper stem

copper stem

in addition to the diagnostic value of x rays, they are useful because of their ability to:

1. dehydrate tissue

2. heat tissue

3. destroy tissue

4. penetrate gold

destroy tissue

a processed film reveals some small circular shaped white spots indicating incomplete processing. this artifact during film processing was caused by:

1. exposure to visible light and incomplete fixing

2. films not agitated in the developer and trapped air bubbles on the film

3. incomplete fixing and films not agitated in the developer

4. exposure to visible light and trapped air bubbles on the film

films not agitated in the developer and trapped air bubbles on the film

you have mounted a full mouth series of radiographs using the buccal method of mounting (convexity facing you). the maxillary molar film on the left side of the mount was cone cut on the distal half of the film. which of the following corrections in technique should be made on a retake of this film?

1. move the film mesially and move the tubehead mesially

2. move the tubehead mesially and the film distally

3. move the tubehead mesially and diret the central ray toward the center of the film

4. move the PID distally and direct the central ray toward the center of the film

move the PID distally and direct the central ray toward the center of the film

the ideal temperature for the x ray developer is:

1. 70 degree F

2. 66 degree F

3. 72 degree F

4. 69 degree F

68 degree F

in order to avoid exposure to secondary radiation, the operator should

1. remain at least 6 ft from the source of radiation

2. stand immediately behind the tubehead

3. stand next to the patient out of the secondary radiation

4. remain at least 4 ft from the patient

remain at least 6 ft from the source of radiation

if the temperature of the developing solution is slightly above normal, radiographs of the proper density may be produced by permitting a:

1. shorter time for developing

2. longer time for fixing

3. longer time for developing

4. shorter time for fixing

shorter time for developing

x ray processing tanks should be kept free of sediment so that the developer solution:

1. will not become contaminated

2. can be left in the tank overnight

3. can be reused for at least one full week

4. can be interchanged with fixing solutions as needed

will not become contaminated

secondary radiation is:

1. less penetrating than primary radiation

2. long target film distance

3. small focal spot

4. increased kilovoltage

less penetrating than primary radiation

x rays belong to a large group of radiations known as

1. particulate radiations

2. hygroscopic radiations

3. alpha radiations

4. corpuscular radiations

5. electromagnetic radiations

electromagnetic radiation

the basic principle in the bisecting angle technique is

1. direct the central ray at the center of the film

2. direct the central ray at right angles to the tooth and the film

3. direct the central ray at right angles to an imaginary line bisecting the angle formed by the long axis of the tooth and the plane of the film

4. none of the above

direct the central ray at right angles to an imaginary line bisecting the angle formed by the long axis of the tooth and the plane of the film

which of the following statements most adequately describes the radiation produced by high kilovoltage

1. short wavelengths of low frequency

2. long wavelengths of high frequency

3. high penetrating waves of low frequency

4. short wavelengths of high frequency

shorter wavelengths of higher frequency

to increase the penetrating ability of the x rays, their wavelengths should be

1. shortened by increasing the kVp

2. shortened by decreasing the kVp

3. lengthened by increasing the kVp

4. shortened by increasing the mA

shortened by increasing the kVp

for maximum penetration of x rays which of the following combinations would you select?

1. 90kV/10mA

2. 85kV/15mA

3. 65kV/15mA

4. 70kV/10mA

90kV/10mA

the kilovoltage of an x ray generating system regulates

1. number of electrons produced

2. thermionic emission

3. the velocity of the electrons traveling from the filament to the target

4. the number of x ray photons produced

the velocity of the electrons traveling from the filament to the target

the 8 in PID is changed to the 16 in PID. at twice the distance, the intensity of the x ray beam is

1. ½ as great

2. ¼ as great

3. 1/6 as great

4. 1/8 as great

¼ as great

when a film is exposed to x ray, what is produced?

1. a visible image

2. a latent image

3. silver bromide salts

4. a gelating

a latent image

the imaginary line from the nose to the ear used as a maxillary reference is known as the

1. midsagittal line

2. occlusal line

3. ala tragus line

4. external oblique line

ala tragus line

which of the following does not control distortion of the radiographic image?

1. target film distance

2. alignment of the film, object and radiation cone

3. object film distance

4. cathode size, the size of the film

cathode side, the size of the film

reticulation of a radiograph is caused by

1. over acidity of fixer

2. overdose of radiation

3. accidental exposure to daylight

4. going from too warm a solution into a cold solution

going from too warm a solution into a cold solution

inter proximal caries can be detected with

1. lateral jaw radiographs

2. occlusal radiographs

3. bitewing radiographs

4. periapical radiographs

bitewing radiographs

lead foil on the back of a film prevents

1. secondary radiation from the teeth

2. excessive exposure

3. the necessity of a collimator

4. back scatter radiation and fogging

back scatter radiation and fogging

a straight black line on a processed film could be caused by

1. static electricity

2. crease form bending

3. careless processing

4. scatter radiation

crease form bending

dark streaks or spots on a processed film could be caused by

1. premature contact with fixer

2. premature contact with developer

3. premature contact with water

4. stained work counter

premature contact with developer

a radiographs shows a partial image and a clear area (straight clear border) what caused this artifact

1. developer level is low fixer level is okay

2. exposure to white light

3. fixer level is low developer level okay

4. solutions not thoroughly mixed

developer level is low fixer level is okay

the kilovolage in an x ray generating system regulates

1. number of electrons produced

2. thermionic emission

3. the velocity of electrons traveling from the filament to the target

4. all of the above

the velocity of electrons traveling from the filament to the target

which of the following tissues is not radiopaque

1. periodontal membrane

2. enamel

3. alveolar bone

4. cortical plate

periodontal membrane

dense tissues

1. permit the passage of x rays and are called radiolucent

2. resist the passage of x rays and are called radiolucent

3. resist the passage of x rays and are called radiopaque

4. permit the passage of x rays and are called radiopaque

resist the passage of x rays and are called radiopaque

the electromagnetic spectrum consists of an orderly arrangement of radiant energies. they travel in a wave form. the shorter the wave form or wavelength, the

1. greater is the energy

2. lesser the energy

3. the more even the oscillatory energy

4. the greater the magnetic index

greater is the energy

a processed film has a pattern design and is light in density. the cause is

1. warm processing solutions

2. kVp too high

3. reversed film

4. low exposure time

reversed film

a radiograph of the mandibular cuspid reveals a distorted blurred area on the lower corner section of the film. the top or upper section of the film has a clear detailed image of the teeth. what caused the distorted image?

1. insufficient vertical angulaiton

2. excessive film bending

3. increased vertical angulation

4. film movement

excessive film bending

a maxillary molar film reveals a triangular radiopaque landmark on the lower corner of the film. the landmark visible in the x ray film is

1. maxillary tuberosity

2. maxillary sinus

3. coronoid process of the mandible

4. hamular process

coroniod process of the mandible

the temperature of the developing solution is 68 degrees F. The films were left in the developer for three minutes. after the processing steps are completed, the final films will be

1. of correct density

2. denser than normal

3. lighter than normal

4. fogged

lighter than normal

which of the following films can be used intraorally and extraorally

1. screen film

2. occlusal film

3. periapical film

4. bitewing film

occlusal

most extraoral radiographs are taken with the aid of

1. a bite block film holder

2. an intensifying screen

3. a pointed x ray cone

4. a cellulose screen

an intensifying screen

what is the function of the raised dot on the film? it identifies

1. the side of the film toward the line of occlusion

2. the side of the film toward the tongue

3. the side of the film toward the beam of radiation

4. the maxillary and mandibular teeth, depending on the film placement

the side of the film toward the beam of radiation

the film speed is directly related to the

1. size of the silver bromide crystals

2. amount of radiation required to produce proper radiographic density

3. exposure latitude

4. rapidity of film development

size of the silver bromide crystals

intensifying screens are used to

1. increase the exposure time

2. improve the image quality

3. decrease radiation to the patient

4. increase the kVp

decrease radiation to the patient

increasing the mA of an x ray machine increases the

1. filament temperature

2. voltage between the cathode and the anode

3. number of photons generated

4. mean energy of the resultant beam

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

1 and 3

which of the following are properties of x rays

1. travel at the speed of light

2. cause chemical changes in matter

3. react with the film emulsion

4. absorbed differently by different forms of matter

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

all are correct

factors that contribute to optimal detail sharpness include

1. short object film distance

2. long target film distance

3. small focal spot

4. increased kilovoltage

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

1,2, 3

which of the following reduces the life of the developing solutions

1. exposure to light

2. exposure to air

3. time

4. heavy use

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

all are correct

blurred radiographs may result from

1. insufficient fixation

2. PID movement

3. cold processing solutions

4. patient movement during exposure

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

2 and 4

light radiographs may be caused

1. shielded side of the film toward the tube during exposure

2. low exposure time

3. exhausted developer

4. overdevelopment

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

1,2,3

in operating x ray equipment, adjustments in milliamperage are made in order to control the

1. penetrating power of radiation

2. speed of the electrons

3. contrast

4. amount of radiation produced

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

only 4

dark films may result from

1. overdeveloping

2. exposure to white light

3. overexposure

4. excessive kilovoltage

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

all are correct

films that overlap during fixing

1. will be clear in the area of contact

2. will be unaffected in the area of contact

3. will be light in the area of contact

4. will be dark or opaque in the area of contact

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

only 4

elongation may be caused by

1. insufficient horizontal angulation

2. poor positioning of the patient’s head

3. excessive vertical angulation

4. insufficient vertical angulation

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

only 4

increasing the kV of the x ray machine increases the

1. filament temperature

2. voltage between the cathode and the anode

3. number of photons generated

4. mean energy of the resultant beam

A. if only 1,2,3

B. if only 1 and 3

C. if only 2 and 4

D. if only 4 is correct

E. if all are correct

2 and 4

which of the following causes dark spots during film development

1. developing solution too warm

2. overdevelopment if exposed film

3. developer contacting film before the actual developing process

4. film contamination with fixer before developing

developer contacting film before the actual developing process

a complete radiographic series has just been processed manually. the dental assistant notes that the films on the bottom of the rack are of different density. what happened

1. developing solution was too cold

2. developing solution was contaminated

3. fixer solution was reaching exhaustion

4. solutions were not stirred before processing

solutions were not stirred before processing

a radiograph turns brown over time. the most likely cause is

1. the darkroom door being opened during processing

2. underwashing

3. underexposure

4. overdevelopment

underwashing

if the door to the darkroom is opened where underdeveloped films have been unwrapped, the processed radiographs will appear

1. light

2. dark

3. unaffected

4. blurred

dark

if the developer is exhausted, the radiographs will appear

1. light

2. fogged

3. dark

4. brown

light

in taking radiographs gagging is usually caused when the film

1. is helped by the patient

2. is moved across the soft palate

3. impinges on the floor of the mouth

is moved across the soft palate

to help the patient control gagging when radiographic film is placed in the mouth, the assistant should

1. eliminate those films that cause the gagging

2. reduce the exposure time

3. distract the patient

4. do nothing to change the procedures; none of the above would help

distract the patient

contrast on a dental radiograph can be altered by changing the

1. angulation

2. kilovoltage

3. milliamperage

4. exposure time

kilovoltage

to eliminate a large dark area below the occlusal surfaces in a dental radiograph you should

1. raise the film in the patient’s mouth

2. lower the film in the patient’s mouth

3. decrease the vertical angulation

4. increase the vertical angulation

raise the film in the patient’s mouth

what change in technique should be used for a maxillary periapical radiograph of a patient who has a shallow palate

1. increase vertical angulation

2. decrease vertical angulation

3. direct horizontal angulation mesially

4. direct horizontal angulation distally

increase vertical angulation

radiographs mounted with the raised portion of the dot toward the observer are examined as though the observer is

1. outside the mouth looking in

2. inside the mouth looking out

3. on the patient’s left side

4. on the patient’s right side

outside the mouth looking in

bitewing films are usually used to

1. detect caries

2. observe apical conditions

3. evaluate the need for occlusal sealants

4. locate impacted teeth

detect caries

a film with thin density and herringbone pattern across it is the result of

1. static electricity

2. film packet reversed

3. double exposure

4. film bending

film packet reversed