Radiology- NBDE II UPDATED ACTUAL Questions and
CORRECT Answers
Barium salts make gutta percha radiopaque.
No barrier, protection of dentist should be 6 feet , 90-135 degrees
how far
most of X ray is converted to Heat
What is the oil in the xray tube for dissipate the heat (cooling)
*cools off the anode
Primary source of radiation to operator scatter from the patient
when taking xray
In performing normal dental diagnostic scatter and secondary
procedures, the operator receives the
greatest hazard from which type of
radiation?
Radiology dosage allowed in a dentist per 50msv , or 5rem per year
year
What does collimination do Decrease xray beam size and volume of irradiated tissue
Circle diameter of 2.75in*
What does collimator NOT do Increase penetrability
Collimination IN XRAY works by Reducing low energy radiation
, What percent does collimator reduce the 60%
volume of tissue being irradiated and
amount of scatter radiation
collimation does everything except ? D. reduce average energy of xray
A. reduce pct exposure
B. reduce operator exposure
C. film fog
D. reduce average energy of xray
Collimating DOES NOT Prevent what Fogging
By what percentage do you decrease 80%
radiation when you use a square collimator
vs. RECTANGULAR
Soft tissue & acrylic radio_____ fairly radiolucent.
Bremsstrahlung radiation high-speed electrons interact w/ Tungsten nuclei. The electron
loses kinetic energy, and this
energy gets converted into photons.
Radiation film badge worn by employees whose work entails exposure to ionizing
radiation.
o Only used to measure occupational dose of radiation.
Cone cut X-ray machine is not lined up properly w/ the film.
o The film/sensor should be perpendicular to the X-ray
collimator.
Focal spot - o Smaller focal spot= better detail, definition, sharpness of the
-smaller image
-larger o Larger focal spot= blurry, increased penumbra (unclear
demarcation of the image outline/blurry)
o Proper angulation of the beam & size of the cone of the X-
ray affects the size of the focal spot.
Source-film distance (SFD) - o Decrease SFD= increase in density because more X-ray
-decrease SFD beam photons can reach the object & the film.
Patients & what X-rays they need o 7 y/o w/ unerupted 1st molars - bitewings, pano
-children/adults o Caries free child w/ closed spaces on posterior teeth -
bitewings
o Adult patient w/ tooth pain + FMX images made less than 1
year - no X-rays needed
Osteoradionecrosis bone healing is reduced due to damaged blood vessels (no
circulation).
o Higher w/ mandibular extractions due to limited blood
supply.
CORRECT Answers
Barium salts make gutta percha radiopaque.
No barrier, protection of dentist should be 6 feet , 90-135 degrees
how far
most of X ray is converted to Heat
What is the oil in the xray tube for dissipate the heat (cooling)
*cools off the anode
Primary source of radiation to operator scatter from the patient
when taking xray
In performing normal dental diagnostic scatter and secondary
procedures, the operator receives the
greatest hazard from which type of
radiation?
Radiology dosage allowed in a dentist per 50msv , or 5rem per year
year
What does collimination do Decrease xray beam size and volume of irradiated tissue
Circle diameter of 2.75in*
What does collimator NOT do Increase penetrability
Collimination IN XRAY works by Reducing low energy radiation
, What percent does collimator reduce the 60%
volume of tissue being irradiated and
amount of scatter radiation
collimation does everything except ? D. reduce average energy of xray
A. reduce pct exposure
B. reduce operator exposure
C. film fog
D. reduce average energy of xray
Collimating DOES NOT Prevent what Fogging
By what percentage do you decrease 80%
radiation when you use a square collimator
vs. RECTANGULAR
Soft tissue & acrylic radio_____ fairly radiolucent.
Bremsstrahlung radiation high-speed electrons interact w/ Tungsten nuclei. The electron
loses kinetic energy, and this
energy gets converted into photons.
Radiation film badge worn by employees whose work entails exposure to ionizing
radiation.
o Only used to measure occupational dose of radiation.
Cone cut X-ray machine is not lined up properly w/ the film.
o The film/sensor should be perpendicular to the X-ray
collimator.
Focal spot - o Smaller focal spot= better detail, definition, sharpness of the
-smaller image
-larger o Larger focal spot= blurry, increased penumbra (unclear
demarcation of the image outline/blurry)
o Proper angulation of the beam & size of the cone of the X-
ray affects the size of the focal spot.
Source-film distance (SFD) - o Decrease SFD= increase in density because more X-ray
-decrease SFD beam photons can reach the object & the film.
Patients & what X-rays they need o 7 y/o w/ unerupted 1st molars - bitewings, pano
-children/adults o Caries free child w/ closed spaces on posterior teeth -
bitewings
o Adult patient w/ tooth pain + FMX images made less than 1
year - no X-rays needed
Osteoradionecrosis bone healing is reduced due to damaged blood vessels (no
circulation).
o Higher w/ mandibular extractions due to limited blood
supply.
