NBDHE Dental Radiography and Interpretation 3

Question 1

What does a 'double lamina dura' on a periapical radiograph suggest?

Accepted Answer

Hypercementosis or Paget's disease affecting the root surface

Answer

Normal anatomical variation

Answer

Periapical abscess formation

Answer

Root resorption

Question 2

Cone-beam computed tomography (CBCT) is preferred over conventional radiography for which specific clinical application in dental hygiene practice?

Accepted Answer

Assessment of alveolar bone morphology and furcation defects in complex periodontal cases

Answer

Routine caries detection in bitewing surveys

Answer

Screening for osteoporosis

Answer

Evaluating enamel integrity in Class V lesions

Question 3

An interproximal carious lesion that radiographically appears to extend through enamel and into the outer third of dentin is classified as:

Accepted Answer

D2 (extends into dentin but not past the outer one-third)

Answer

D1 (enamel only)

Answer

D3 (extends into the inner two-thirds of dentin)

Answer

D4 (involves the pulp)

Question 4

Which radiation safety device is MOST appropriate for a dental hygienist to use to monitor cumulative occupational radiation exposure?

Accepted Answer

Thermoluminescent dosimeter (TLD) or digital optically stimulated luminescence (OSL) badge

Answer

Geiger-Müller counter

Answer

Ionization chamber in the operatory

Answer

Lead apron only

Question 5

A periapical radiograph showing a well-defined, unilocular radiolucency associated with the crown of an unerupted tooth is MOST consistent with:

Accepted Answer

Dentigerous (follicular) cyst

Answer

Odontogenic keratocyst

Answer

Ameloblastoma

Answer

Adenomatoid odontogenic tumor

Question 6

The primary purpose of the lead apron with thyroid collar in dental radiography is to:

Accepted Answer

Protect radiosensitive tissues — gonads and thyroid — from scatter radiation

Answer

Reduce primary beam exposure at the source

Answer

Minimize patient movement during exposure

Answer

Prevent secondary radiation from the film/sensor