DANB DANB Dental Unit & Environmental Infection Control 1 — Questions and Answers
Question 1: What is the primary purpose of flushing dental unit waterlines at the beginning of each clinical day?
- To warm the water for patient comfort
- To reduce microbial contamination that accumulates overnight in stagnant water (Correct answer)
- To check water pressure
- To remove air bubbles from lines
Correct answer: To reduce microbial contamination that accumulates overnight in stagnant water
Flushing dental unit waterlines at the start of each day reduces the microbial load that accumulates in stagnant water overnight, lowering patient and staff exposure risk.
Question 2: Biofilm in dental unit waterlines is primarily composed of:
- Blood and saliva from patients
- Naturally occurring environmental waterborne bacteria (Correct answer)
- Chemical disinfectant residue
- Air from the dental compressor
Correct answer: Naturally occurring environmental waterborne bacteria
Dental unit waterline biofilm is primarily composed of naturally occurring environmental waterborne bacteria (such as Pseudomonas and Legionella) that colonize tubing walls.
Question 3: What water quality standard does the CDC recommend for water used in dental handpieces and air/water syringes during non-surgical procedures?
- Tap water quality (≤500 CFU/mL)
- Sterile water only
- Potable water quality (≤500 CFU/mL heterotrophic bacteria) (Correct answer)
- Distilled water only
Correct answer: Potable water quality (≤500 CFU/mL heterotrophic bacteria)
The CDC recommends that water used in dental procedures meet potable water standards of ≤500 CFU/mL of heterotrophic bacteria for non-surgical procedures.
Question 4: Which type of water should be used during surgical procedures that involve cutting through bone or soft tissue?
- Tap water
- Sterile saline or sterile water delivered through a sterile irrigation system (Correct answer)
- Water meeting potable quality standards
- Distilled water
Correct answer: Sterile saline or sterile water delivered through a sterile irrigation system
Surgical procedures require sterile saline or sterile water delivered through a sterile system to prevent infection at the surgical site from waterborne contaminants.
Question 5: How should the dental chair and light handle be managed between patients for infection control?
- Wipe with a dry cloth
- Use surface barriers changed between patients, or clean and disinfect with EPA-registered product (Correct answer)
- Clean only at end of day
- Leave as-is; they are rarely contaminated
Correct answer: Use surface barriers changed between patients, or clean and disinfect with EPA-registered product
Dental chairs, light handles, and other clinical contact surfaces should be covered with surface barriers changed between patients, or cleaned and disinfected with an EPA-registered hospital-grade disinfectant.
Question 6: What is the infection control concern with dental unit air compressors?
- They consume too much electricity
- They can introduce contaminated water into the dental unit waterlines
- Contaminated air from the compressor can be delivered to the patient through air-water syringes (Correct answer)
- They produce heat that damages instruments
Correct answer: Contaminated air from the compressor can be delivered to the patient through air-water syringes
Dental air compressors can harbor microbial contamination, and if the compressor intake draws in room air containing pathogens, it can potentially deliver contaminated air through handpieces and air-water syringes.
DANB DANB Dental Unit & Environmental Infection Control 1
What is the primary purpose of flushing dental unit waterlines at the beginning of each clinical day?