Cross Infection and Microbiology

Question 1

What is direct cross infection?

Answer 1

Direct contact with a contaminated person (sneezing, physical contact)

Question 2

What is indirect cross infection?

Answer 2

Not having direct contact with the person (contaminated instruments)

Question 3

What is disinfection?

Answer 3

Destruction of most microorganisms, but not spores and certain viruses

Question 4

Advantages of disinfection

Answer 4

Useful for work surfaces and other non-sterilisable items

Question 5

Disadvantages of disinfection

Answer 5

Doesn’t achieve sterilisaton and the products often do not have a long shelf life

Question 6

What is sodium hypochlorite used for?

Answer 6

On non-metal surfaces as it can corrode metal or cause staining on materials

Question 7

What is chlorhexidine gluconate used for?

Answer 7

Used in hibiscrub hand wash and corsodyl mouthwash

Question 8

What is isopropyl alcohol used for?

Answer 8

For dental chairs, work surface and general disinfection

Question 9

Why can isopropyl alcohol not be used as an instrument cleaner?

Answer 9

It can bind blood proteins to steel

Question 10

What is sterilisation?

Answer 10

The destruction of all microorganisms including spores

Question 11

How can sterilisation be achieved?

Answer 11

Using an autoclave, hot air oven, glass bead sterilisation or industrial sterilisation

Question 12

How does an autoclave work?

Answer 12

Steam from distilled water is put under pressure

Question 13

What are the hold values for an autoclave?

Answer 13

2-3 bar of pressure for a minimum of 3 minutes at 134 degrees ceclius.

Question 14

What is an N type autoclave?

Answer 14

Non-vacuum

Question 15

What is an S type autoclave?

Answer 15

Specialist autoclave

Question 16

What is a B type autoclave?

Answer 16

Vacuum

Question 17

When would glass bead sterilisation be used?

Answer 17

For endodontic files between stages on the same patient.

Question 18

What type of radiation is used for industrial sterilisation?

Answer 18

Gamma radiation

Question 19

What is industrial sterilisation used for?

Answer 19

Sterilising single use items.

Question 20

What is the best method of cross infection prevention?

Answer 20

Single use items

Question 21

Why does water supplied to the surgery need to have air gap?

Answer 21

To prevent back flow to the mains

Question 22

What is used to clean a bodily fluid spillage?

Answer 22

1% fresh sodium hypochlorite solution with warm water

Question 23

What vaccinations should you have?

Answer 23

Hepatitis B, tetanus and all childhood diseases (measles, mumps, rubella, polio)

Question 24

What is the yellow mop used for?

Answer 24

Clinical areas

Question 25

What is the red mop used for?

Answer 25

Toilets

Question 26

What is the green mop used for?

Answer 26

Kitchen

Question 27

What is the blue mop used for?

Answer 27

Offices/waiting areas

Question 28

What is pathology?

Answer 28

The study of disease and its effects on body tissues

Question 29

How can infections enter the body?

Answer 29

Through cuts/abrasions in the skin, eyes, inhalation and swallowing

Question 30

What is the body's first stage of defense?

Answer 30

Skin or mucus membranes such as in the mouth and nose

Question 31

What is the body's second stage of defense?

Answer 31

Secretions such as saliva, tears and sweat

Question 32

What is the body's third stage of defense?

Answer 32

Through immunity.

Question 33

What is acquired immunity?

Answer 33

Life long protection, usually from a prior exposure to the infection or a vaccination

Question 34

What is natural immunity?

Answer 34

Where the body has a natural resistance to a disease

Question 35

What is passive immunity?

Answer 35

Passed from the mother to the baby during pregnancy

Question 36

What are the five signs on inflammation?

Answer 36

Swelling, redness, heat, pain and loss of function

Question 37

What are the four groups of microorgansisms?

Answer 37

Fungi, virus, bacteria and protozoa

Question 38

What does pathogenic mean?

Answer 38

They can cause disease

Question 39

What does non-pathogenic mean?

Answer 39

They cannot cause disease

Question 40

How does fungi spread in the body?

Answer 40

Grows across outer body cells and tissues

Question 41

What are hyphae?

Answer 41

When the fungal networks branch out

Question 42

What fungi is of importance in dentistry and what infections can it cause?

Answer 42

Candida albicans, causing denture stomatitis and angular chelitis

Question 43

What are aerobic bacteria?

Answer 43

Thrive in oxygen rich environments

Question 44

What are anaerobic bacteria?

Answer 44

Prefer low oxygen environments

Question 45

What are the four types of bacteria?

Answer 45

Bacilli (rod shaped with pointed ends), cocci (round), spirochetes (spiral) and endospores

Question 46

What are spores?

Answer 46

When conditions aren't favorable for the bacteria, sometimes they can create a protective shell and become dormant. When conditions become favorable again, they can resume normally.

Question 47

How do viruses exist?

Answer 47

As protein capsules

Question 48

What is a prion?

Answer 48

An infectious agent composed of protein. They affect the brain and nervous system.

Question 49

What disease can a prion cause that is relevant to dentistry?

Answer 49

Creutzfeldt-Jakob disease, this is untreatable and fatal.

Question 50

What is the standard PPE used for?

Answer 50

Mask - prevent aerosol inhalation Gloves - prevents microorganisms entering through cuts Eye protection - prevents microorganisms entering through the eyes