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 NELDA exam has 230 questions and runs 3 hours.
These 10 free NELDA questions are organized by exam domain, so you can see how each part of the National Entry Level Dental Assistant blueprint is tested. Reveal the answer and explanation under each question.
After the dentist administers mandibular anesthesia, testing confirms pulpal anesthesia of a molar, but its adjacent buccal gingiva remains sensitive. Which nerve's sensory territory accounts for the remaining gingival sensation?
Correct answer: B - Long buccal nerve
At a 6-year-old's examination, a tooth is erupting immediately behind the primary mandibular right second molar. No primary tooth has been lost in that area. Which Universal designation belongs on the chart for the erupting tooth?
Correct answer: C - 30 - permanent mandibular right first molar
An occlusal record describes the maxillary first molar's mesiobuccal cusp as mesial to the mandibular first molar's buccal groove. The maxillary central incisors are retroclined, with a deep vertical overbite. These findings correspond to which Angle classification?
Correct answer: C - Class II, division 2
A medically stable patient with HIV is scheduled for a routine restoration and has no signs of an additional transmissible infection. A coworker suggests changing the appointment solely because of the HIV diagnosis. Which plan is appropriate?
Correct answer: C - Keep the appointment and apply Standard Precautions appropriate to the procedure.
Routine monitoring of a maintained dental unit finds 240 CFU/mL of heterotrophic bacteria in its output water. The day's procedures include a nonsurgical restoration and oral surgery requiring irrigation of exposed bone. How should the result guide water selection?
Correct answer: D - Use unit water for the restoration and sterile irrigant through a sterile bypass delivery system for surgery.
A steam sterilizer's weekly spore test is positive for the first time. The matching unprocessed control grows as expected, while mechanical readings and chemical indicators are satisfactory. No implantable items were processed. Under CDC dental guidance, what should happen before another patient-care load is processed?
Correct answer: B - Remove the sterilizer from service, review procedures, and immediately repeat the spore test using the same cycle.
The dentist requests a repeat premolar bitewing because the proximal contacts overlap and cannot be evaluated for caries. The crowns are sharp, exposure is appropriate, and the intended teeth are fully recorded. Correcting which variable will address the overlap?
Correct answer: A - Horizontal beam angulation
An intraoral series shows similar round radiolucencies near the mandibular second premolar apices on both sides. The root outlines and the surrounding lamina dura are intact. The appearance most strongly favors:
Correct answer: A - Superimposed mental foramina
A patient who is 10 weeks pregnant has localized dental pain. After examining her and reviewing existing images, the dentist prescribes one periapical image. She asks whether pregnancy alone means it should be postponed. The most accurate response is:
Correct answer: A - A clinically necessary dental image can be taken during pregnancy using dose-optimized technique.
During digital radiography, an assistant needs to operate a clean, unbarriered mouse. Both gloves have contacted the patient's saliva, and no clean assistant is available. Which sequence maintains asepsis when moving to the computer and then back to intraoral work?
Correct answer: D - Remove gloves, perform hand hygiene, use the mouse, then perform hand hygiene and don fresh gloves.
The NELDA exam also covers these domains. Drill them in the full free practice test:
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