Lecture 9 Flashcards
Microorganisms colonize dental water lines forming_____ leading to contaminated water and aerosols
biofilms
Biofilms
Microbial colones that adhere to solid surfaces in areas where there is sufficient moisture
How many CFU/ml sets the level of Safe Water Drinking Act
500 CFU/ml
What does CFU stand for?
Colony Forming Unit
Where do the majority of microorganism come from ______
water source
Some microorganisms come from ____-_____ device failure
anti-retraction
What is an anti-retraction valve?
prevents back flow of fluid from patient into dental unit water line (DUWL)
Failure of anti-retraction valve results in
allows retraction of fluid from patient #1 into the waterline, contaminating lines for patient #2
Dental unit water vs Tap Water
Dental unit water-
- Very small diameter tubing
- Very slow flow rate-drips
- hydrophobic tubing makes biofilm attachment easy
- Left stagnant for hours
- Chlorine dissipates over 24 hrs
Tap Water-
- 1/2” diameter
- 5 liters/minutes= 1000X dental flow
- copper is antimicrobial and bacteriostatic
- Line is flushed with fresh water frequently
- Chlorinated at every use
How do microbes in DUWL- surfaces begin colonization
Minerals found in water are deposited on surface which help bacteria to adhere
As the diameter of the tubing ______ the surface area covered by biofilm increases. At the same time, the volume of water passing by ____
decreases; decreases
What percent of Legionellosis in a dentists’ blood is considered occupational exposure
5%
What are symptoms of Legionellosis
- Flu like symptoms called Pontiac Fever
- pneumonia
Legionnaires’ Disease is caused by what bacteria
Legionella
Legionnaires’ Disease affects primarily the _____
lungs
