BU DENTAL RADIOLOGY EXAM Question and
Answer 2026 | Updated Practice Questions
and Solutions | A+ Verified
• What does the x-ray tube contain? -✓✓cathode anode and focusing cup
• Who discovered what x-rays were? -✓✓Wilhelm Conrad Roentgen
• Properties of Xrays -✓✓1. X-rays are weightless package of pure energy
2. They have no electrical charge
3. They travel at the speed of light
4. They travel in straight line but diverge from a central focus
5. They have enough energy to ionize and cause biological damage
6. They can cause certain substances to fluoresce and affect photographic film.
• In a dental x-ray tube the electrons are emitted from the what? -✓✓Cathode (-)
• X-ray is produced when electrons moving at a high speed hit the tungsten target in a
x-ray tube. -✓✓True
• an assistant may hold the film or sensor in place for the pt during exposure -✓✓False
• As soon as a film or sensor is placed in a pt's mouth it is considered contaminated? -
✓✓True
• X-rays are ionizing radiation. -✓✓True
• Bitewings show what? -✓✓Crowns and permant fixtures are interporximal surfaces of
the teeth.
• In the paralleling technique the xray is directed perpendicular to the bisecting line
between the angle of the long axis of the tooth and the film/sensor -✓✓True, explain..
So when you are parallelling, the angle you make when you are bisecting is
perpendicular to the angle
• Pt;s should be drapped with a led apron prior to any radiographic images? -✓✓True
• Which if not a safety precaution for taking x-rays?
-Always stand behind an appropriate barrier?
-Never stand in the path of primary radiation
-Never stabilize the tube head during radiation
, -If neccessary hold the film in the pt's mouth -✓✓If neccessary hold the film in the pt's
mouth, never hold the film or sensor in the pts mouth.
• X-rays travel at the speed of light? -✓✓True
• Nerve cells can be regennerated? -✓✓False, No- Dense things like bone can and
perm fixtures, restorations.
• Which of these have an infulence on radiation protection?
-Safe equipment
-Skilled operator
-Lead aprons and thyroid collars
-All of the above -✓✓All of the above
• primary radiation -✓✓travels from source to detector
(useful)
• scatter radiation -✓✓changes direction during passage through intervening med
• Leakage radiation -✓✓: radiation that originates from the X-ray tube and is not the
primary beam.
• Filters in an x-ray tube is made of what? -✓✓Aluminum
• The radiographs which reveal the entire teeth with the apical region is called what? -
✓✓Periapical
• X-ray instruments should always be what? -✓✓Sterlized
• Film Composition -✓✓Film has a green color. The film has emulsion on both sides.
There are two principal components:
• periapical film size (central/lateral/canine) -✓✓0 or 1
• periapical film size (premolar/molar) -✓✓2
• premolar bitewing film size -✓✓2
• Base of film -✓✓Plastic supporting material on which the emulsion is coated with an
adhesive.
• Tree-like lightening black streaks on a processed film are caused by what? -✓✓Static
electricity when drying
Answer 2026 | Updated Practice Questions
and Solutions | A+ Verified
• What does the x-ray tube contain? -✓✓cathode anode and focusing cup
• Who discovered what x-rays were? -✓✓Wilhelm Conrad Roentgen
• Properties of Xrays -✓✓1. X-rays are weightless package of pure energy
2. They have no electrical charge
3. They travel at the speed of light
4. They travel in straight line but diverge from a central focus
5. They have enough energy to ionize and cause biological damage
6. They can cause certain substances to fluoresce and affect photographic film.
• In a dental x-ray tube the electrons are emitted from the what? -✓✓Cathode (-)
• X-ray is produced when electrons moving at a high speed hit the tungsten target in a
x-ray tube. -✓✓True
• an assistant may hold the film or sensor in place for the pt during exposure -✓✓False
• As soon as a film or sensor is placed in a pt's mouth it is considered contaminated? -
✓✓True
• X-rays are ionizing radiation. -✓✓True
• Bitewings show what? -✓✓Crowns and permant fixtures are interporximal surfaces of
the teeth.
• In the paralleling technique the xray is directed perpendicular to the bisecting line
between the angle of the long axis of the tooth and the film/sensor -✓✓True, explain..
So when you are parallelling, the angle you make when you are bisecting is
perpendicular to the angle
• Pt;s should be drapped with a led apron prior to any radiographic images? -✓✓True
• Which if not a safety precaution for taking x-rays?
-Always stand behind an appropriate barrier?
-Never stand in the path of primary radiation
-Never stabilize the tube head during radiation
, -If neccessary hold the film in the pt's mouth -✓✓If neccessary hold the film in the pt's
mouth, never hold the film or sensor in the pts mouth.
• X-rays travel at the speed of light? -✓✓True
• Nerve cells can be regennerated? -✓✓False, No- Dense things like bone can and
perm fixtures, restorations.
• Which of these have an infulence on radiation protection?
-Safe equipment
-Skilled operator
-Lead aprons and thyroid collars
-All of the above -✓✓All of the above
• primary radiation -✓✓travels from source to detector
(useful)
• scatter radiation -✓✓changes direction during passage through intervening med
• Leakage radiation -✓✓: radiation that originates from the X-ray tube and is not the
primary beam.
• Filters in an x-ray tube is made of what? -✓✓Aluminum
• The radiographs which reveal the entire teeth with the apical region is called what? -
✓✓Periapical
• X-ray instruments should always be what? -✓✓Sterlized
• Film Composition -✓✓Film has a green color. The film has emulsion on both sides.
There are two principal components:
• periapical film size (central/lateral/canine) -✓✓0 or 1
• periapical film size (premolar/molar) -✓✓2
• premolar bitewing film size -✓✓2
• Base of film -✓✓Plastic supporting material on which the emulsion is coated with an
adhesive.
• Tree-like lightening black streaks on a processed film are caused by what? -✓✓Static
electricity when drying
