EFDA Radiography & Infection Control 5 — Questions and Answers
Question 1: What is the correct procedure for handling the lead apron between patients?
- Sterilize in the autoclave after each use
- Wipe with an intermediate-level disinfectant (Correct answer)
- Send to laundry for washing
- No decontamination is required between patients
Correct answer: Wipe with an intermediate-level disinfectant
Lead aprons cannot be autoclaved or laundered; they must be wiped down with an EPA-registered intermediate-level disinfectant between patients.
Question 2: Which of the following radiographic errors produces a clear, unexposed area on the processed film?
- Double exposure
- Overlapping
- Cone cut (partial image) (Correct answer)
- Film reversal
Correct answer: Cone cut (partial image)
A cone cut occurs when the PID is not centered over the film/sensor, leaving a clear, unexposed crescent-shaped area on the radiograph where X-rays did not reach.
Question 3: Bloodborne pathogen training for dental employees must be provided:
- Once at initial employment only
- Every five years
- At initial employment and annually thereafter (Correct answer)
- Only when an exposure incident occurs
Correct answer: At initial employment and annually thereafter
OSHA's Bloodborne Pathogens Standard (29 CFR 1910.1030) requires employers to provide training at initial employment and annually to all at-risk employees.
Question 4: When processing conventional dental radiographs, a film that appears too dark (overexposed) may result from:
- Developer temperature too low
- Developer solution too concentrated or development time too long (Correct answer)
- Fixer solution too concentrated
- Insufficient rinsing between developer and fixer
Correct answer: Developer solution too concentrated or development time too long
Overdevelopment due to high developer temperature, excessive concentration, or prolonged development time causes excessive silver halide reduction, producing a dark film.
Question 5: Which infection control step is required BEFORE seating the next patient in a radiography operatory?
- Flush the waterlines for 30 seconds
- Disinfect all clinical contact surfaces and apply surface barriers (Correct answer)
- Sterilize the X-ray unit in the autoclave
- Change the HEPA filter in the air purifier
Correct answer: Disinfect all clinical contact surfaces and apply surface barriers
All clinical contact surfaces must be disinfected with an EPA-registered hospital disinfectant and/or covered with fresh surface barriers before seating each new patient.
Question 6: What is the biological effect that dental X-rays are most concerned with in terms of long-term risk?
- Thermal burns to tissue
- Stochastic effects such as carcinogenesis (Correct answer)
- Acute radiation syndrome
- Deterministic effects on bone marrow
Correct answer: Stochastic effects such as carcinogenesis
Stochastic effects, including the potential induction of cancer, are the primary long-term concern with low-dose dental X-ray exposure, as their probability increases with cumulative dose.
Question 7: Which finding on a radiograph would most likely indicate the need for endodontic evaluation?
- Calculus deposit on tooth surface
- Periapical radiolucency at the root apex (Correct answer)
- Horizontal bone loss between teeth
- Interproximal radiolucency in enamel only
Correct answer: Periapical radiolucency at the root apex
A periapical radiolucency at the root apex indicates bone destruction around the apex, suggesting pulpal necrosis or abscess that typically requires endodontic (root canal) treatment.
EFDA Radiography & Infection Control 5
What is the correct procedure for handling the lead apron between patients?