Deck 24: Dental Unit Waterlines

Question 1

Which of the following statements is true about dental unit waterlines?

A)Viruses cannot multiply in the DUWL.
B)The use of sterile water in the self-contained water reservoir ensures that water will be sterile at the point of delivery.
C)Microfilters reduce the bacterial contamination of water and destroy the biofilms that colonize the DUWLs.
D)Flushing for 20 to 30 seconds after each patient will remove biofilms from the lines.

Answer 1

Viruses cannot multiply in the DUWL.

Question 2

Backflow from low-volume saliva ejectors occurs when the patient:

A)is positioned in a reclined position in the dental chair.
B)closes his or her lips around the tip of a saliva ejector.
C)first turns on the saliva ejector.
D)has been using a saliva ejector for more than 10 minutes.

Answer 2

closes his or her lips around the tip of a saliva ejector.

Question 3

The options available for testing the quality of waterline cleaning include:

A)there is no availability for testing of the dental waterline cleaning.
B)using a commercial testing service.
C)using an in-office test kit.
D)both b and c.

Answer 3

both b and c.

Question 4

Disposable in-line microfiltration cartridges should be replaced:

A)according to the manufacturer's recommendations.
B)between patients.
C)once a week.
D)twice a day.

Question 5

Biofilm can contain many types of bacteria,_______ protozoa.

A)fungi, algae, and
B)fungi, and algae, but not
C)and fungi, but neither algae nor
D)but not fungi, algae, or

Question 6

_____ is a type of "plaque" that develops inside DUWLs and consists of bacterial cells and other microbes that adhere to surfaces and form a protective slime layer.

A)Infection
B)Microfilm
C)Biofilm
D)Slime

Question 7

Factors contributing to the formation of bacteria in water lines include:

A)stagnant water.
B)water heating.
C)none of the above.
D)both a and b.

Question 8

The dental office gets its water from _____,and the water then is routed to ____ found in the dental office.

A)municipal supplies; sinks, toilets, air conditioners, and the dental unit
B)tanks delivered to the office; sinks, toilets, air conditioners, and the dental unit
C)wells; sinks, toilets, air conditioners, and the dental unit
D)a and b only
E)a and c onlyf. all of the above

Question 9

The advantages of self-contained water reservoirs include which of the following?

A)They are less expensive to use.
B)Dental personnel can select the quality of water used.
C)Maintenance of the water system is under the control of the dental staff.
D)Both b and c are advantages of self-contained reservoir systems.

Question 10

The type of water used during surgery where bone is exposed should be:

A)heated municipal water.
B)distilled water from a self-contained system.
C)sterile water only in a sterile syringe.
D)any type of water may be used.

Question 11

Waterborne diseases have been found in:

A)hospitals.
B)schools.
C)dental water lines.
D)all of the above.

Question 12

While using water from municipal lines for routine dental procedures,biofilm and bacteria can be carried out reaching the patient through the use of:

A)faucet.
B)handpiece.
C)waterline.
D)both b and c.

Question 13

Dental team members can reduce their exposure to the dental unit water by using:

A)the HVE.
B)a dental dam.
C)masks, protective eyewear, and/or face shields.
D)both a and c.

Question 14

When choosing a chemical agent to give dental unit water lines a "shock" treatment,care should be taken to:

A)not use a product that will damage the dental units.
B)check with the manufacturer to determine the recommended chemical product and protocol for maintenance.
C)not use more than once a month.
D)both a and b.

Question 15

The bacteria in the biofilm are up to _____ times more resistant to chemical germicides than planktonic bacteria.

A)3
B)5
C)100
D)1500

Question 16

To temporarily reduce the microbial count and to help clean the handpiece waterlines,DUWLs should be flushed:

A)for 20 to 30 seconds between patients.
B)every morning for several minutes.
C)every evening for 20 minutes.
D)both a and b.

Question 17

Research has shown that microbial counts in new dental unit waterlines can reach _____ CFUs/ml (colony-forming units per milliliter) within 5 days of installation.

A)10
B)500
C)1000
D)200,000

Question 18

Advantages of using self-contained water reservoirs include:

A)increasing the number of bacteria in waterlines.
B)decreasing the number of bacteria in waterlines.
C)giving the dental office control over quality of water used.
D)all of the above.

Question 19

Methods of reducing the level of bacterial contamination in waterlines include:

A)yearly replacement of all water lines.
B)back-flushing the lines with a bleach solution.
C)self-contained water reservoirs.
D)using waterlines of smaller diameter.

Question 20

Planktonic bacteria are:

A)unable to survive in DUWLs.
B)prevented from entering DUWLs by use of anti-retraction valves.
C)free floating in the water.
D)in the biofilm attached to DUWL walls.

Question 21

Which of the following techniques in dentistry has been proven to cause adverse health effects on patients?

A)Back suction
B)Clogged suction line
C)Backflow from saliva ejector
D)None of the above

Question 22

Flushing the dental waterlines for several minutes every morning and for 20-30 seconds between patients will help to:

A)reduce prep time.
B)reduce the microbial count.
C)both a and b.
D)none of the above.