Infection Control

Question 1

What is the transfer of infection from person to person called?

Answer 1

Direct cross-infection

Question 2

What is the transfer of infection to person to equipment and onto a second person called?

Answer 2

Indirect cross-infection

Question 3

What is the basic principle of standard precautions?

Answer 3

To assume that any patient may be infected with any micro-organism at any time, and therefore they pose an infection risk to all dental staff and other patients.

Question 4

What are the 4 stages of decontamination (also referred to as ‘reprocessing’)?

Answer 4

Cleaning
Disinfection
Inspection
Sterilisation

Question 5

What can bleach-based cleaners be used for?

Answer 5

Containing sodium hypochlorite used to disinfect all non-metallic and non-textile surfaces and to disinfect laboratory items

Question 6

What can aldehyde-based cleaners be used on?

Answer 6

Metallic surfaces and to soak laboratory items

Question 7

What are isopropyl alcohol wipes used for?

Answer 7

To disinfect items such as exposed x-ray film packets for safe handing during processing

Question 8

What is chlorhexidene gluconate used for?

Answer 8

As an irrigating disinfectant during root canal treatments, and as a skin cleanser

Question 9

During manual cleaning, why is cold water used?

Answer 9

Because hot water ‘fixes’ contaminants such as blood and makes them more difficult to remove

Question 10

What are the 3 daily duties for maintaining and testing the working efficiency of the ultrasonic bath?

Answer 10

Strain/filter cleaning
Tank draining
Cleaning check

Question 11

What are the 2 additional weekly duties carried out to maintain the ultrasonic bath?

Answer 11

Safety check
Protein residue test

Question 12

What are the 5 stages of a washer-disinfector?

Answer 12

Flush (45C)
Wash
Rinse
Thermal disinfection
Drying

Question 13

What are the 3 additional in-house tests which should be carried out on a washer-disinfector once every 6 months?

Answer 13

Automatic control test - to ensure cycle parameters set are achieved
Chemical dosing - to ensure detergent is released correctly into cycle
Thermometric disinfection test - using heavily soiled load, temperatures are tested

Question 14

List and describe the various maintenance and testing requirements of autoclaves which can be carried out by a trained dental nurse.

Answer 14

1. Daily test to record temp, pressure and time interval. Kept in dated log book
2. Daily automatic control test using TST strip
3. Steam penetration test for vacuum autoclaves to ensure steam does penetrate to inside of packaging. Usually a Helix or Bowie-Dick test
4. Only purified or reverse osmosis water
5. Water shod be drained from reservoir and replaced daily
6. Door seal and safety devices used to prevent door opening during the cycle must be visually checked weekly

Question 15

List and describe the maintenance and testing requirements for autoclaves to be carried out by an authorised engineer.

Answer 15

1. Annual inspection to ensure autoclave operates correctly, issue certificate to that effect
2. Each autoclave must be checked for it confirmation with the Pressure Systems Safety Regulations on regular basis
3. Practice insurance policy must include third party liability cover for autoclaves, in case of their explosion and injury to patients/staff

Question 16

List the decontamination room area set out in the ideal best practice order.

Answer 16

Set down area for dirty items
Hand-washing sink
Instrument washing sink
Ultrasonic bath (if required)
Rinsing sink
Washer-disinfector
Illuminated magnifier for inspection
Autoclave
Packaging and storage

Question 17

When would you use sodium hypochlorite

Answer 17

Disinfect all non metallic and non fabric surfaces within the surgery
Disinfect impressions and removable prostheses before transferring between patients and lab
Clean up blood spillages

Question 18

Washer disinfectors five stages

Answer 18

Flush
Wash
Rinse
Thermal Disinfection
Drying