10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The DAR exam has 100 questions and runs 2 hours.
These 10 free DAR questions are organized by exam domain, so you can see how each part of the Dental Assisting Radiography blueprint is tested. Reveal the answer and explanation under each question.
A round intraoral collimator is replaced with a rectangular collimator matched to the receptor. Tube voltage, mAs, and added filtration remain unchanged. Which benefit comes specifically from this modification?
Correct answer: A - A smaller volume of tissue is irradiated.
A 72-year-old patient with a tremor can remain still only briefly despite supported positioning. An acceptable exposure at this site ordinarily uses 6 mA for 0.20 seconds. The calibrated unit permits the settings below, with kVp, filtration, and geometry unchanged. Which combination preserves the original mAs while best limiting motion blur?
Correct answer: D - 8 mA for 0.15 seconds.
A referral packet contains two CBCT examinations obtained on different scanners. The numeric gray-value readouts differ at a corresponding area of mandibular bone. Before treating the difference as evidence of changed bone density, what limitation must be considered?
Correct answer: A - The numeric gray values may not be directly comparable across the two systems.
On a right molar bitewing, the crowns and crestal bone are sharp and fully included, but several proximal contacts overlap. The receptor remained stable during exposure. Which adjustment directly addresses this defect?
Correct answer: B - Redirect the beam horizontally through the interproximal contacts.
A small oval radiolucency appears over the apex of a mandibular second premolar. The lamina dura around the apex remains continuous. On an additional clinically indicated projection with different horizontal angulation, the radiolucency appears separate from the root. What best explains this appearance?
Correct answer: B - The mental foramen superimposed near the premolar apex.
The left and right sides of a panoramic image are symmetric, and the chin position is acceptable. A broad dark band overlies the maxillary roots and obscures their apices. Which patient instruction would specifically prevent this air-space shadow?
Correct answer: C - Swallow, then keep your tongue against the roof of your mouth.
Patient films are uniformly too light this morning. A separately pre-exposed processing-control film also develops to a lower density than its established baseline. Yesterday's control was satisfactory. Where should troubleshooting begin?
Correct answer: C - Check developer temperature, development time, and solution activity.
At 10 weeks of an uncomplicated pregnancy, a patient presents with localized molar pain. After examining her, the dentist prescribes one periapical image to guide treatment today. She agrees to imaging but asks whether it must wait until later in pregnancy. How should the assistant respond?
Correct answer: D - Explain that the indicated image can be obtained now with optimized technique.
A bitewing has a small cone cut at its outer corner. All prescribed proximal contacts and the required crestal bone are visible, and the dentist confirms that the image answers the clinical question. An assistant suggests repeating it to remove the artifact. What is the appropriate disposition of this image?
Correct answer: B - Retain the image without repeating it because it fulfills the prescribed diagnostic task.
After a bitewing series, an intact barrier is removed from a reusable digital sensor. Its instructions prohibit heat sterilization and high-level disinfection but permit a compatible EPA-registered hospital disinfectant with a tuberculocidal claim. The detachable intraoral holder is heat-tolerant. How should the two reusable components be reprocessed before the next patient?
Correct answer: A - Clean and disinfect the sensor with the compatible product; clean and heat-sterilize the holder.
The full bank has 1,020 more DAR questions with explanations.
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