# North Carolina practice questions: Sterilization and infection control exam

Ten original North Carolina practice questions on sterilization and infection control exam, each answered on this page with a rationale and a source.

Last updated: 2026-09-08.

## Question 1

A patient denies any infectious disease and appears healthy. What is the appropriate baseline for the appointment?

- A. Use gloves only if the patient later reports an infection.
- B. Skip eye protection because the medical history is negative.
- C. Use Standard Precautions throughout the encounter.
- D. Use precautions only during visibly bloody procedures.

**Answer C:** Use Standard Precautions throughout the encounter.

Standard Precautions apply to all patients regardless of known or suspected infection. Medical history and appearance do not reliably identify every infection. The protections selected still depend on anticipated exposure during the task.

**Common trap:** Treating screening as a replacement for baseline infection prevention.

Source: [Standard Precautions — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/summary/standard-precautions.html)

## Question 2

Hands are visibly contaminated with blood after a procedure. Which method is appropriate?

- A. Wipe hands on a clean towel without washing.
- B. Wash with soap and water.
- C. Put on a fresh pair of gloves without cleaning.
- D. Alcohol hand rub alone because it is always interchangeable with washing.

**Answer B:** Wash with soap and water.

CDC specifies soap and water when hands are visibly dirty or contaminated with blood or other potentially infectious material. Alcohol rub is an option in appropriate non-visibly-soiled situations; covering or wiping away visible soil is insufficient.

**Common trap:** Applying an acceptable method without checking the condition of the hands.

Source: [Standard Precautions — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/summary/standard-precautions.html)

## Question 3

A reusable mouth mirror is heat tolerant. What is the appropriate processing principle?

- A. Disinfection is always preferred to heat for every semicritical item.
- B. A barrier eliminates the need to process it.
- C. A low-level surface wipe is sufficient because it does not cut tissue.
- D. Clean and heat sterilize it between patients.

**Answer D:** Clean and heat sterilize it between patients.

A mirror contacts mucous membranes and is semicritical. CDC recommends heat sterilization for heat-tolerant semicritical dental items. The absence of tissue penetration does not make it a noncritical surface.

**Common trap:** Equating not cutting with low risk.

Source: [Best Practices for Sterilization in Dental Settings — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/dental-ipc-faqs/dental-sterilization.html)

## Question 4

A barrier on a dental-unit control is removed after a patient. What should happen next?

- A. Replace the barrier without inspecting the surface beneath it.
- B. Inspect underneath, clean/disinfect if contaminated, and replace the barrier.
- C. Spray disinfectant on top of the used barrier and reuse it.
- D. Leave the same barrier for the next patient if it looks clean.

**Answer B:** Inspect underneath, clean/disinfect if contaminated, and replace the barrier.

CDC calls for barrier changes between patients and inspection of the surface beneath them, with cleaning and disinfection when contamination occurs. An apparently clean used barrier can still transfer contamination. Reusing or treating its outside does not complete turnover.

**Common trap:** Assuming the presence of a barrier removes the need to inspect and change it.

Source: [Best Practices for Environmental Infection Prevention and Control — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/dental-ipc-faqs/cleaning-disinfecting-environmental-surface.html)

## Question 5

A sharps container has reached its fill limit. What is the appropriate response?

- A. Close and replace it without overfilling.
- B. Shake the container until more space appears.
- C. Push the contents down with a gloved hand.
- D. Leave used needles on the tray until the next day.

**Answer A:** Close and replace it without overfilling.

Sharps containers must not be allowed to overfill. Manipulating the contents creates puncture risk, and temporary exposed storage does not solve the problem. Proper placement and timely replacement are part of the prevention system.

**Common trap:** Trying to create capacity by handling contaminated sharps.

Source: [NC DOL Subpart Z — 1910.1030 Bloodborne Pathogens](https://www.labor.nc.gov/subpart-z-toxic-and-hazardous-substances)

## Question 6

A practice opens a second facility that is not physically connected to its first office. What does the designated-staff rule require?

- A. One remote coordinator may automatically cover all facilities.
- B. A designee is required only for the office where most procedures occur.
- C. Designate a person at each office but substitute any annual training for the required approved course.
- D. Designate an on-site staff member for each noncontiguous facility who completes the required Department-approved course.

**Answer D:** Designate an on-site staff member for each noncontiguous facility who completes the required Department-approved course.

The North Carolina rule is specific to each noncontiguous facility, meaning physically unconnected locations. The designated staff member must complete the prescribed approved training. Central administrative support does not remove the on-site requirement.

**Common trap:** Treating multiple locations as one facility because they share ownership.

Source: [10A NCAC 41A .0206 — Infection Prevention–Health Care Settings](http://reports.oah.state.nc.us/ncac/title%2010a%20-%20health%20and%20human%20services/chapter%2041%20-%20epidemiology%20health/subchapter%20a/10a%20ncac%2041a%20.0206.pdf)

## Question 7

Which situation best illustrates indirect contact transmission?

- A. A susceptible worker inhales infectious airborne particles.
- B. A splash reaches a worker’s unprotected eye.
- C. Contaminated gloves contaminate a device used for another patient.
- D. An infected patient’s oral fluid directly contacts a worker’s nonintact skin.

**Answer C:** Contaminated gloves contaminate a device used for another patient.

Indirect contact uses a contaminated intermediate object. A describes inhalation; B describes a mucous-membrane splash; D describes direct contact with patient material. The key identifies transfer through the contaminated device.

**Common trap:** Using one control for every route of transmission.

Source: [Guidelines for Infection Control in Dental Health-Care Settings — 2003](https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5217a1.htm)

## Question 8

When should hand hygiene occur in relation to gloves and patient care?

- A. Only before gloving for surgical procedures.
- B. Only at the beginning and end of the workday.
- C. Before and after each patient, before putting gloves on, and immediately after removing them.
- D. Only after a glove visibly tears.

**Answer C:** Before and after each patient, before putting gloves on, and immediately after removing them.

CDC’s hand-hygiene indications include these transitions. Whole-day intervals, visible-tear triggers, or surgery-only hygiene omit opportunities for contamination during routine dental care. The type of hand-hygiene product still depends on the task and visible soil.

**Common trap:** Remembering a product but forgetting the moments when it must be used.

Source: [Standard Precautions — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/summary/standard-precautions.html)

## Question 9

An air-driven low-speed motor removable from the dental unit is wiped externally between patients. Why is this inadequate?

- A. Only high-speed handpieces need internal processing.
- B. Contamination can occur internally; wiping does not process the motor.
- C. Wiping is adequate if no blood is visible.
- D. An external barrier reliably prevents contamination of the motor’s internal components.

**Answer B:** Contamination can occur internally; wiping does not process the motor.

CDC includes these removable dental-unit low-speed motors and reusable prophylaxis angles in its cleaning and heat-sterilization guidance. Internal contamination is not removed by an exterior wipe. Speed and the absence of visible blood do not create exceptions.

**Common trap:** Evaluating only the accessible outside of a complex device.

Source: [Best Practices for Dental Handpieces — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/dental-ipc-faqs/dental-handpieces.html)

## Question 10

Visible blood is on an uncovered clinical-contact surface. Which response fits CDC dental guidance?

- A. Use a high-level instrument disinfectant on all room surfaces regardless of its labeling.
- B. Remove visible soil with detergent alone and then use the surface.
- C. Cover the blood with fresh barrier film.
- D. Clean, then apply a labeled tuberculocidal hospital disinfectant.

**Answer D:** Clean, then apply a labeled tuberculocidal hospital disinfectant.

For visible blood or other potentially infectious material on a clinical-contact surface, CDC calls for intermediate-level disinfection after cleaning. An appropriate tuberculocidal hospital disinfectant supplies that level. A barrier, cleaning alone, or an unlabeled high-level chemical use does not complete the appropriate process.

**Common trap:** Skipping cleaning or confusing product strength with an appropriate labeled use.

Source: [Best Practices for Environmental Infection Prevention and Control — May 15, 2024](https://www.cdc.gov/dental-infection-control/hcp/dental-ipc-faqs/cleaning-disinfecting-environmental-surface.html)

## Next step

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Official reference: [North Carolina State Board of Dental Examiners — online examinations](https://www.ncdentalboard.org/onlineexams.htm). Original exam-style questions written for study, never recalled exam content. Independent educational preparation, not legal or clinical advice, and not affiliated with or endorsed by the North Carolina State Board of Dental Examiners. Follow the instructions issued with your own Board exam registration.