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Infection Control: INBDE study notes and practice questions

Infection control questions are practical and rule-based: how to process instruments, how to protect staff and patients, and what to do after an exposure. Regulations and documentation are tested too.

461 practice questions · 6 patient cases

Practice Infection Control

Where it fits in the official INBDE blueprint

Practice and Profession (adhering to standard precautions). Nearest foundation knowledge area: FK 7. See the content outline for the official weights. This mapping is approximate: real items combine a clinical area with a foundation area.

What this area tests

High-yield checklist

Common traps

These notes are original study aids, not official exam content. Confirm clinical details against current guidelines.

Sample questions

1. What infection control precautions should be taken when treating a patient with Hepatitis C?

  1. Wear a face shield but no mask
  2. Wear double gloves for all procedures
  3. Use standard precautions during invasive procedures
  4. Use high-level chemical sterilization for all instruments
Show answer and explanation

Correct answer: C. Use standard precautions during invasive procedures

Hepatitis C virus (HCV) is transmitted via blood and body fluids (bloodborne pathogen). Standard precautions (previously called universal precautions) are the appropriate level of infection control for ALL patients regardless of known infection status, and they are sufficient for HCV patients. Standard precautions include: gloves, surgical masks, protective eyewear, gown when splatter is anticipated, proper sharps handling, and instrument sterilization/surface disinfection. No additional precautions beyond standard precautions are required for HCV. There is no vaccine for HCV, so consistent standard precaution compliance is the only protection for dental healthcare workers.

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2. According to CDC guidelines, what is an appropriate method for disinfecting dental impressions?

  1. Immersion in 1:10 diluted sodium hypochlorite for 10 minutes
  2. Soaking in 70% isopropyl alcohol for 30 seconds
  3. Rinsing with water only
  4. Autoclaving the impression
Show answer and explanation

Correct answer: A. Immersion in 1:10 diluted sodium hypochlorite for 10 minutes

CDC guidelines recommend that dental impressions be rinsed with water to remove blood and saliva, then disinfected using an intermediate-level disinfectant before being sent to the dental laboratory. A 0.5% sodium hypochlorite solution (1:10 dilution of household bleach, approximately 5,000 ppm) is an appropriate intermediate-level disinfectant for impressions. Immersion for 10 minutes achieves adequate disinfection. Alcohol sprays (70% isopropyl alcohol) are less effective and do not achieve intermediate-level disinfection for all impression materials. Water alone is insufficient. Autoclaving distorts most impression materials and is inappropriate.

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3. What is the protection level of masks used in dentistry?

  1. 50%
  2. 75%
  3. 95%
  4. 99%
Show answer and explanation

Correct answer: C. 95%

Masks used in dentistry, particularly N95 respirators, provide 95% protection against airborne particles when properly fitted. They are essential for infection control, especially during aerosol-generating procedures. Regular surgical masks provide a lower level of protection and are not as effective against small airborne particles.

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4. Which of the following best demonstrates the efficiency level of a surface disinfectant used in a dental office?

  1. Ability to kill Mycobacterium tuberculosis (tuberculocidal activity)
  2. Ability to kill all bacteria including spores (sporicidal activity)
  3. Ability to kill Staphylococcus aureus only
  4. Ability to kill hepatitis B virus
Show answer and explanation

Correct answer: A. Ability to kill Mycobacterium tuberculosis (tuberculocidal activity)

The standard used to demonstrate intermediate-level disinfection efficacy is tuberculocidal activity (ability to kill Mycobacterium tuberculosis). Mycobacterium tuberculosis is among the most resistant non-spore-forming organisms and is used as a benchmark because if a disinfectant can kill it, it will also kill most other vegetative bacteria, fungi, and lipid-enveloped viruses. Disinfectants are classified as low-level (kills most bacteria and some viruses), intermediate-level (tuberculocidal; also kills non-lipid viruses), or high-level (kills all except large numbers of bacterial spores). Sporicidal activity would indicate sterilization, not disinfection. The ADA and CDC use tuberculocidal efficacy as the standard for dental surface disinfectants.

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5. Which of the following is classified as REGULATED MEDICAL WASTE in a dental office?

  1. Ejector (saliva ejector) tip
  2. Scalpel blade
  3. Paper towels
  4. Empty anesthetic carpule
Show answer and explanation

Correct answer: B. Scalpel blade

A scalpel blade is a sharp contaminated with blood or body fluids and is classified as regulated (biohazardous) medical waste — specifically as 'sharps.' Sharps must be disposed of in puncture-resistant sharps containers. Ejector tips are single-use disposables but are not classified as regulated waste unless visibly contaminated with blood. Non-contaminated disposables go into regular waste.

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6. Each of the following is a bloodborne pathogen per OSHA EXCEPT:

  1. HIV
  2. Hepatitis B
  3. Hepatitis C
  4. Mumps
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Correct answer: D. Mumps

Mumps is caused by a paramyxovirus transmitted via respiratory droplets (airborne/droplet) — NOT a bloodborne pathogen. OSHA's bloodborne pathogens standard covers HIV, HBV, HCV, and other pathogens present in blood. Mumps is not transmitted through blood contact. HIV, HBV, and HCV are all classic bloodborne pathogens.

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7. A patient discloses they are HIV-positive. What infection-control approach should the dental team use?

  1. Standard precautions, the same as for every patient
  2. Refuse treatment
  3. Treat only at the end of the day in a separate isolation room
  4. Add special precautions beyond standard for this patient only
Show answer and explanation

Correct answer: A. Standard precautions, the same as for every patient

Standard precautions treat all blood and body fluids as potentially infectious and apply to EVERY patient regardless of known status. No additional precautions are needed specifically for HIV, and refusing care is discrimination.Other options: Refusing care or end-of-day segregation is unnecessary and unethical/illegal; HIV does not require airborne isolation.Key exam takeaway: Standard precautions apply to all patients; HIV status does not change routine dental infection control.

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8. What is the standard infection control protocol for intraoral digital radiography sensors, which cannot be heat-sterilized?

  1. Single barrier
  2. No barrier needed if the sensor is wiped once after use
  3. Full heat sterilization in an autoclave between patients
  4. Single-use disposable sensors only, with no reusable sensors permitted
Show answer and explanation

Correct answer: A. Single barrier

Because digital radiography sensors are heat- and chemical-sensitive electronic devices that cannot be autoclaved, standard protocol uses a single protective barrier sleeve/cover during use, combined with a 'double wipe' disinfection technique — surface disinfection both before placing the barrier and again after removing it — providing an extra layer of protection against cross-contamination.

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Patient cases

All Infection Control questions (461)