Dental Radiography Quiz
Questions: 16 · 10 minutes
1. A periapical image clearly shows the crowns and alveolar crest, but the root apices are missing. What is the most likely positioning problem?
The exposure time was too short
The patient moved before the exposure ended
The horizontal angulation was too steep
The receptor did not extend far enough beyond the apices
2. A patient reports being pregnant and may need a dental radiograph for a current clinical concern. Which statement reflects sound general radiation-protection practice?
Clinically justified images may be taken using optimization and applicable local safety procedures
All dental radiography must be postponed until after delivery
Only panoramic imaging may be used during pregnancy
Dental radiography is restricted to the second trimester in every circumstance
3. Several structures on an otherwise correctly exposed image have blurred outlines. Which cause best explains this appearance?
Failure to place the embossed identification dot occlusally
Excessive horizontal angulation
Insufficient receptor coverage
Movement of the patient, receptor, or tubehead during exposure
4. A clinician needs an image of an entire tooth, including the surrounding apical bone. Which projection is most appropriate?
Bitewing
Periapical
Panoramic
Posterior occlusal
5. Which radiation-protection principle calls for keeping patient exposure as low as reasonably achievable while still obtaining the needed diagnostic information?
The paralleling principle
The inverse square law
ALARA
The rule of isometry
6. Which beam-limiting change most directly reduces the volume of patient tissue exposed during an intraoral radiograph?
Increasing image-receptor sensitivity
Adding display contrast after exposure
Using rectangular instead of circular collimation
Using a longer exposure time
7. During an intraoral exposure, which routine approach best protects the operator?
Hold the receptor steady for the patient while turning the face away
Use a receptor holder and follow the approved barrier or distance-and-angle procedure
Stand beside the tubehead so its position can be watched
Ask a companion to hold the receptor whenever positioning is difficult
8. A periapical image made with the bisecting-angle technique shows teeth that look elongated. Which adjustment most directly addresses this error?
Increase the vertical angulation
Decrease the vertical angulation
Rotate the tubehead horizontally
Move the receptor farther from the teeth
9. On a panoramic image, the anterior teeth appear unusually narrow and blurred. Which positioning error is the most likely cause?
The patient was positioned too far back
The patient failed to place the tongue against the palate
The patient slumped during the exposure
The patient was positioned too far forward
10. What is a primary purpose of a dental radiography quality-assurance program?
To make every image use identical exposure settings
To eliminate the need for operator training
To produce consistently useful images while reducing avoidable errors and repeat exposures
To replace clinical justification with routine imaging schedules
11. When anatomy and receptor placement permit, which geometric change helps reduce image magnification?
Increasing the object-to-receptor distance
Minimizing the object-to-receptor distance
Shortening the source-to-object distance
Using a larger focal spot
12. A newly acquired radiograph is diagnostically unacceptable because the target area was cut off. What should happen before considering a repeat exposure?
Identify the positioning or alignment cause and correct it
Choose a different projection without reviewing the first attempt
Increase the exposure time to ensure the anatomy appears
Repeat immediately with the same setup to check whether the error recurs
13. A processed intraoral image has a clear, curved unexposed area along one edge. What is the most likely cause?
The x-ray beam was not centered over the entire receptor
The patient moved during the exposure
The horizontal angulation was incorrect
The receptor received excessive exposure
14. Which intraoral image is primarily used to examine the crowns of upper and lower posterior teeth and their interproximal bone levels on the same image?
Periapical image
Cross-sectional localization image
Occlusal image
Bitewing image
15. Which structure normally appears radiolucent on a dental radiograph?
Enamel
Pulp chamber
Cortical bone
Metallic restoration
16. On a posterior bitewing, the interproximal contacts are overlapped even though the receptor covered the intended teeth. What was most likely incorrect?
Exposure time
Vertical angulation
Horizontal angulation
Receptor sensitivity