NDECC Infection Control and Sterilization 1 — Questions and Answers
Question 1: Which sterilization method is considered the gold standard for heat-stable dental instruments?
- Dry heat sterilization
- Steam autoclave sterilization (Correct answer)
- Chemical vapor sterilization
- Ethylene oxide sterilization
Correct answer: Steam autoclave sterilization
Steam autoclave sterilization is the gold standard because it reliably kills all microorganisms including spores at 121–134°C under pressure.
Question 2: According to CDC guidelines, dental handpieces should be cleaned and sterilized between patients using which process?
- High-level disinfection
- Intermediate-level disinfection
- Steam autoclave sterilization (Correct answer)
- Surface disinfection only
Correct answer: Steam autoclave sterilization
The CDC recommends that dental handpieces be heat-sterilized (autoclaved) between patients, not just disinfected, because they contact mucous membranes.
Question 3: What is the appropriate biological indicator (spore test) organism used to verify steam autoclave sterilization?
- Bacillus cereus
- Geobacillus stearothermophilus (Correct answer)
- Bacillus subtilis
- Clostridium difficile
Correct answer: Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are used as the biological indicator for steam sterilization because of their high heat resistance.
Question 4: When should sterilization pouches be inspected before use on a patient?
- Only if the pouch appears visibly damaged
- Before each use to check chemical indicator and pouch integrity (Correct answer)
- At the start of each clinic day as a batch
- Only when the autoclave cycle log shows an error
Correct answer: Before each use to check chemical indicator and pouch integrity
Each sterilization pouch must be inspected before use to confirm the chemical indicator has changed color and the seal is intact, ensuring the item was properly processed.
Question 5: Which level of personal protective equipment (PPE) is required when manually scrubbing contaminated dental instruments before sterilization?
- Gloves only
- Mask and gloves only
- Heavy-duty utility gloves, mask, eye protection, and gown (Correct answer)
- Standard examination gloves and mask
Correct answer: Heavy-duty utility gloves, mask, eye protection, and gown
Heavy-duty utility gloves, mask, eye protection, and protective gown are required during instrument scrubbing to protect against punctures, splashes, and aerosols from contaminated instruments.
Question 6: An ultrasonic cleaner is used in the instrument reprocessing area primarily to:
- Sterilize instruments using high-frequency sound waves
- Remove bioburden from instruments before sterilization (Correct answer)
- Disinfect instruments to a high level
- Replace the need for autoclave sterilization for low-risk items
Correct answer: Remove bioburden from instruments before sterilization
Ultrasonic cleaners use cavitation to remove debris and bioburden from instruments prior to sterilization; they do not sterilize or disinfect.
Question 7: Which of the following surfaces in the dental operatory is classified as a 'clinical contact surface' requiring disinfection or barrier protection between patients?
- Waiting room chairs
- Dental unit light handle (Correct answer)
- Sterilization area countertop
- Reception desk keyboard
Correct answer: Dental unit light handle
The dental unit light handle is a clinical contact surface that is touched during patient care and can become contaminated, requiring barrier protection or disinfection between patients.
NDECC Infection Control and Sterilization 1
Which sterilization method is considered the gold standard for heat-stable dental instruments?