NDHCE Dental Radiography 1 — Questions and Answers
Question 1: Which of the following X-ray techniques is used to detect interproximal caries and alveolar bone levels?
- Periapical radiograph
- Bitewing radiograph (Correct answer)
- Occlusal radiograph
- Panoramic radiograph
Correct answer: Bitewing radiograph
Bitewing radiographs are specifically designed to show interproximal surfaces and the crest of alveolar bone on both arches simultaneously.
Question 2: What is the recommended target distance (focal-film distance) for a standard periapical radiograph using paralleling technique?
- 8 inches
- 12 inches
- 16 inches (Correct answer)
- 20 inches
Correct answer: 16 inches
The paralleling technique uses a 16-inch focal-film distance to minimize image magnification and distortion.
Question 3: Which ionizing radiation unit measures the biological effect of radiation on human tissue?
- Roentgen
- Rad
- Rem (Sievert) (Correct answer)
- Coulomb/kg
Correct answer: Rem (Sievert)
The rem (or Sievert in SI units) measures the dose equivalent, accounting for the biological effect of radiation on tissue.
Question 4: A radiograph appears too light (underexposed). Which of the following is the most likely cause?
- Excessive milliamperage
- Increased kilovoltage
- Insufficient exposure time (Correct answer)
- Processing in hot developer
Correct answer: Insufficient exposure time
An underexposed radiograph appears too light because insufficient exposure time results in too few X-ray photons reaching the film or sensor.
Question 5: Which of the following best describes the SLOB (Same Lingual Opposite Buccal) rule used in dental radiography?
- Used to determine the correct vertical angulation
- Used to locate the position of objects in the buccolingual dimension (Correct answer)
- Used to calculate radiation dosage
- Used to set kilovoltage for panoramic images
Correct answer: Used to locate the position of objects in the buccolingual dimension
The SLOB rule is used with the tube-shift technique to determine whether an object is on the lingual or buccal side by observing how it moves relative to a reference object when the X-ray tube is shifted.
Question 6: Which type of radiograph provides the most comprehensive view of the entire dentition, jaws, and surrounding structures in a single image?
- Full-mouth series
- Bitewing series
- Panoramic radiograph (Correct answer)
- Cephalometric radiograph
Correct answer: Panoramic radiograph
A panoramic radiograph captures a broad view of the entire maxilla, mandible, teeth, TMJ, and surrounding structures on a single extraoral film.
NDHCE Dental Radiography 1
Which of the following X-ray techniques is used to detect interproximal caries and alveolar bone levels?