1
Within 5 days of installation, research has shown that microbial counts in new dental unit waterlines (DUWLs) can reach _____ CFUs/mL.
10
500
1000
200,000
200,000
Planktonic bacteria are:
unable to survive in DUWLs.
prevented from entering DUWLs by use of antiretraction valves.
free floating in the water.
in the biofilm attached to DUWL walls.
free floating in the water.
Advantages of using self-contained water reservoirs include:
increasing the amount of biofilm in waterlines.
the ability to sterilize that inside parts of the dental unit.
giving the dental office control over quality of water used.
complete elimination of biofilms and bacteria from dental waterlines.
giving the dental office control over quality of water used.
The type of plaque that develops inside DUWLs, consisting of bacterial cells and other microbes, is called:
Biofilm
Which of the following statements is true about dental unit waterlines?
Viruses cannot multiply in the DUWL.
The use of sterile water in the self-contained water reservoir ensures that water will be sterile at the point of delivery.
Microfilters reduce the bacterial contamination of water and destroy the biofilms that colonize the DUWLs.
Flushing for 20 to 30 seconds after each patient will remove biofilms from the lines.
Viruses cannot multiply in the DUWL.
The type of water used during surgery where bone is exposed should be:
only sterile water delivered in a sterile syringe.
The bacteria in the biofilm are more resistant to chemical germicides than planktonic bacteria by a factor of:
3.
5.
100.
1500.
1500.
The number of waterborne bacteria in community water is kept below _____ colony-forming units (CFUs) per milliliter.
500
Flushing the dental unit waterlines (DUWLs) for several minutes at the beginning of the treatment day and for 20 to 30 seconds between patients will help to:
reduce prep time between dental patients.
reduce the microbial count of bacteria in the dental unit waterlines.
eliminate bacterial biofilm from the dental unit waterlines.
clean the dental unit water that is used for surgery involving exposure of bone.
reduce the microbial count of bacteria in the dental unit waterlines.
Methods of reducing the level of bacterial contamination in waterlines include all of the following except:
yearly replacement of all waterlines.
chemical treatment regimens.
self-contained water reservoirs.
microfiltration.
yearly replacement of all waterlines.
Which of the following types of water will likely have the highest bacterial colony-forming unit (CFU) count?
Tap water from the sink.
Distilled water purchased in a plastic container.
Water from a drinking fountain.
Water from an air-water syringe.
Water from an air-water syringe.
Which of the following techniques in dentistry has been shown to be a potential source of cross-contamination as a result of backflow into a patient’s mouth?
Hand scaling with periodontal curettes.
Use of an ultrasonic or piezo scaler to clean accretions from teeth.
Low-volume saliva ejectors.
Use of a high-speed handpiece for cavity preparation.
Low-volume saliva ejectors.
To reduce the microbial count temporarily and to help clean the handpiece waterlines, DUWLs should be flushed:
at the beginning of the day for several minutes and for 20 to 30 seconds between patients.
Water from municipal lines can be harmful to a patient because it may contain a biofilm with:
human immunodeficiency virus (HIV).
bacterial cells.
chlorine.
fluoride.
bacterial cells.
True or False---
I am working hard and I have no doubt I will be successful on this assesment!
TRUE!!!!!!!