Sterilization, Disinfection, and Antisepsis Flashcards Preview

AU 15- Oral Micro > Sterilization, Disinfection, and Antisepsis > Flashcards

Flashcards in Sterilization, Disinfection, and Antisepsis Deck (112)
Loading flashcards...
1
Q

True or False: Most human pathogens have been isolated from oral secretions.

A

True

2
Q

What are the four (five) routes for transmission of disease during dental treatment?

A
  1. Direct
  2. Indirect
  3. Spatter
  4. Aerosolization
  5. Fomites
3
Q

What is direct transmission?

A

contact with the infectious lesion, saliva, or blood

4
Q

What is indirect transmission?

A

transmission via contaminated intermediate objects

5
Q

What is spatter?

A

droplets of blood, saliva, plaque, or nasopharyngeal secretions

6
Q

What is a fomite?

A

a germ on an inanimate object (i.e. on charts in the chart room)

7
Q

What is the difference between spatter and aerosolization?

A
spatter = droplets
Aerosol = small, floating particles
8
Q

_____ is a pathogen that was named after a river in the Congo where it was first recognized in 1976.

A

Ebola

9
Q

What is the fatality rate of Ebola?

A

50%

10
Q

True or False: Increased age is associated with a higher mortality rate of Ebola.

A

True

11
Q

How infectious is Ebola?

A

HIGHLY infectious, a SINGLE virus may be enough

12
Q

What is the difference in Ebola’s infectiousness and contagiousness?

A

Highly infectious: single viron

Moderately contagious: NOT transmitted through the air

13
Q

How is Ebola tranmitted?

A

direct contact with body fluids or contaminated objects from infected persons

14
Q

What is the incubation period of Ebola?

A

2 to 21 days

15
Q

True or False: Ebola is not contagious until symptoms develop.

A

True

16
Q

Is Ebola enveloped or non-enveloped? How does this effect its ability to be killed?

A

enveloped

the lipid membrane is susceptible, therefore it can be killed by alcohol or hand sanitizer

17
Q

True or False: the risk of transmitting HIV from patient to health care worker is very high.

A

False

18
Q

True or False: The risk for transmitting Hepatitis B if very low.

A

False!!!

19
Q

Epidemic resurgence of ______ is related to the immigrant population.

A

Tuberculosis

20
Q

How is tuberculosis transmitted?

A

Coughing of infective aerosols followed by subsequent inhalation

21
Q

______ _______ type I and II are frequently present in the oral cavity, may be transmitted to healthcare workers, and may cause blindness.

A

Herpes Simplex

22
Q

What is viral whitlow?

A

herpetic lesion on the finger (may transmit virus from healthcare worker to patient via this lesion)

23
Q

Which immunizations are recommended for healthcare personnel?

A

Hep B
Flu
MMR
Varicella Zoster

24
Q

What are “critical” items?

A

items that come into contact with tissues or the vascular system (i.e. burs and endo tools)

25
Q

What are “semi-critical” items?

A

items that come into contact with mucous membranes or non-intact skin (i.e. curing lights)

26
Q

What are “non-critical” items?

A

items that touch in tact skin (i.e. blood pressure cuff)

27
Q

What is sterilization?

A

destruction or removal of all life forms INCLUDING SPORES

28
Q

Sterilization can only be used on _____ objects and can be via ____ or ____ means.

A

inanimate

heat or chemical

29
Q

What does it mean to disinfect?

A

to inhibit or destroy pathogens without killing spores; used only on inanimate objects

30
Q

What are antiseptics used for?

A

to destroy pathogenic microorganisms on living tissues; they are safe for use on human tissue

31
Q

True or False: Antiseptics and disinfectants can be used interchangeably.

A

False

32
Q

The FDA regulates liquid chemical sterilants used on ____ and ____ items; whereas, the EPA regulates chemical disinfectants that are used on _______ surfaces and gaseous sterilants.

A

Critical and semicritical

noncritical

33
Q

What are the three levels of disinfection?

A

High-level
Intermediate-level
Low-level

34
Q

High-level disinfection destroys __________, with the exception of _________.

A

all microorganisms

bacterial spores

35
Q

Intermediate level disinfection will inactivate Mycobacterium _________, vegetative bacteria, most ____, and most _____ but does not necessarily kill bacterial spores.

A

tuberculosis
viruses
fungi

36
Q

Why are disinfectants tested against M.tuberculosis when it is transmitted through the air?

A

Simply: it is a strong (hearty) bacteria that provides good results when used for testing

37
Q

What do low-level disinfectants kill?

A

most bacteria
some viruses
some fungi
*will NOT kill M.tuberculosis or bacterial spores

38
Q

Critical items must be _____ because any microbial contamination could transmit disease.

A

sterilized

39
Q

Semicritical items should be ______ if possible; however, _____ or _____-level disinfection is absolutely required.

A

sterilized

high or intermediate

40
Q

Why do noncritical items require only a low-level disinfectant?

A

noncritical items come into contact with intact skin, not mucous membranes, and skin acts as an effective barrier to most microorganisms
(protect your skin on the weekends! don’t let exposed cuts put you in danger)

41
Q

What are three methods for proper sterilization?

A

saturated steam under pressure
dry heat
unsaturated chemical vapor

42
Q

Which method of sterilization is most efficient and reliable?

A

Heat; proteins are denatured by heat = kills the organism

43
Q

True or False: Items do not need to be cleaned before sterilization, the high temperatures will melt away any excess debris.

A

False: must be cleaned or the bioburden may prevent sterilization

44
Q

What is an autoclave?

A

the oldest, most commonly used method of sterilization, uses steam under pressure

45
Q

What are the autoclave conditions? (temperature, pressure, time)

A

121 degrees Celsius (250 F)
15 psi
15-20 minutes

46
Q

When using the autoclave, items must be packaged in material that allows for _______ which is at _____ psi.

A

penetration of steam

15

47
Q

One advantage of the autoclave is the short cycle time; how long does it take?

A

15-20 minutes

48
Q

True or False: Steam under pressure will penetrate faster than dry heat.

A

True

49
Q

The autoclave sterilizes at _____ degrees Celsius or _____ degrees Fahrenheit.

A

121

250

50
Q

What are the four main disadvantages of the autoclave?

A
  1. corrosion/dulling
  2. deposits
  3. remain wet at end of cycle
  4. destruction of heat sensitive materials
51
Q

What is “flash steam sterilization”? Do we use this in the school?

A

Statim Brand:

its a smaller, more rapid, hotter, higher pressure unit for sterilization. Yes there is one in the dental coach.

52
Q

How fast is the flash steam sterilization? Compare it to the autoclave.

A

6-12 mins

autoclave is 15-20

53
Q

Dry heat sterilization works in a similar way to steam because the heat denatures viral proteins. However, what is the difference in its ability to denature?

A

dehydrated proteins are more stable, so dry heat requires HIGHER temperatures for LONGER time frames

54
Q

Why must packages be kept somewhat underfilled during dry heat sterilization?

A

Heat transfer is very slow: you don’t want to overfill the oven or packages

55
Q

What is the advantage to dry heat sterilizing?

A

does not corrode or dull cutting edges

56
Q

Compared to the autoclave, dry heat sterilization requires ____ temperatures and ______ time.

A

higher (160 C for 2 hours, or 170 C for 1 hour)

longer

57
Q

True or False: Dry heat sterilization is better for handpieces than the autoclave.

A

False: dry heat cannot be used for handpieces at all, therefore you would still need an autoclave too

58
Q

_____ ______ transfer sterilization reduces time of cycling and does not corrode or dull instruments.

A

Rapid Heat (12 mins for wrapped items, 6 mins unwrapped)

59
Q

What are the disadvantages to using Rapid Heat Transfer?

A

not suitable for handpieces

destruction is greater because the temperature is so hot (190 C, or 375 F)

60
Q

______ ______ Vapor Sterilization depends on heat, water, and chemical synergy.

A

Unsaturated Chemical

61
Q

Chemical vapor sterilization uses mixtures of methyl alcohol, _______, ketone, acetone, and water.

A

formaldehyde

62
Q

Do instruments corrode with chemical vapor sterilization?

A

no

63
Q

What is the main disadvantage to chemical vapor sterilization?

A

chemical odor and safety concerns; emissions

64
Q

How long does chemical vapor sterilization take?

A

20-40 minutes (under 20psi)

65
Q

Sterilization is ________ weekly in order to follow CDC and state law guidelines.

A

monitored

66
Q

Treated tapes and heat sensitive strips are examples of ______ monitoring and indicate that items were heated.

A

chemical

67
Q

True or False: Indicators ensure that temperatures were reached and maintained for adequate sterilization.

A

False: they only indicated that the item was heated; autoclave tape changes color long before sterilization conditions are met

68
Q

______ indicators (monitoring) provide the BEST guarantee of sterilization.

A

Biological

69
Q

What do biological monitors contain?

A

spores that are more resistant than most viruses or bacteria (NOT PATHOGENIC); ex. Bacillus stearothermophilus is used in autoclaves

70
Q

What are the two forms of biological monitors?

A

Glass vials: contain spore suspension and pH indicator

Spore-impregnated Strips: sent to service for check

71
Q

What do you look for in the glass vials of biological monitors?

A

color change

spores germinate and produce acid, the pH strip will change colors in response to the acid production

72
Q

Do not use _____ sterilants in place of heat, only use when heat is not appropriate.

A

chemical

73
Q

What is the common chemical sterilant that is used to irreversibly inactivate nucleic acids and proteins?

A

ETO (ethylene oxide)

74
Q

ETO is ______!

A

explosive

75
Q

ETO will burn tissue but some still use it because it does not _______.

A

damage heat or moisture sensitive materials

76
Q

How long does ETO take?

A

10-16 hours at room temperatures (25 C, 75 F)

77
Q

Which chemical is used most often, is considered to be the “most potent germicide,” and requires 10 hours of immersion in solution?

A

Glutaraldehydes

78
Q

True or False: Glass bead sterilization is FDA approved.

A

False

79
Q

What are disadvantages to using Glutaraldehyde solutions?

A
long immersion time
allergenic
tissue irritation
fume toxicity
corrosive to metals
80
Q

Do not ______ if you can ______.

A

disinfect

sterilize

81
Q

What kind of chemical disinfectant is used in CaviWipes?

A

quaternary ammonium alcohol

82
Q

CaviWipes are _____-level disinfectants for ______ items.

A

intermediate

semicritical

83
Q

What level disinfectant is Accelerated Hydrogen Peroxide?

A

intermediate

84
Q

AHP is the newest product on the market, what are the main advantages to its use?

A

no odor
non-toxic
short contact time (1 min!!)
cleans and disinfects

85
Q

Which disinfectants are considered to be “cytoplasmic poisons” due to their penetration and disruption of microbial cell walls and denaturing of intracellular proteins?

A

Phenols (toxic to tissue, don’t use as antiseptic = phe-NO NOs)

86
Q

True or False: Phenols must be used in conjunction of another agent because it is a poor cleaning agent.

A

True

87
Q

If using alcohols as a single agent of disinfection, it must be ______ % alcohol.

A

60-80%

88
Q

Alcohols are considered _____ to ____-level disinfectants.

A

intermediate to low

89
Q

True or False: Alcohol makes proteins insoluble and tenaciously adherent to surfaces which can protect microorganisms.

A

True

90
Q

Detergents are ____-level disinfectants.

A

low

91
Q

Detergents provide mechanical ______ and disrupt _______.

A

cleansing

some cell membranes

92
Q

Gram _____ bacteria are more susceptible to antimicrobial effects of detergents.

A

positive

93
Q

Let’s talk about charges (+/-): Detergents and soaps are _____, whereas quaternary ammonium solutions are _____.

A

anionic (not effective against gram negative, “opposites attract” is relevant here too)
cationic

94
Q

Quaternary Ammonium is a _____-level surface disinfectant suitable for _____ items. However, Quaternary Ammonium-Alcohol Combinations are ____-level disinfectants.

A

low
noncritical
intermediate

95
Q

True or False: A tincture of iodine is a good antiseptic against both gram positive and gram negative bacteria.

A

True

96
Q

Which solution (iodine or iodophor) has these characteristics: less irritating, less allergenic, and longer acting?

A

iodophor

97
Q

True or False: Iodine and iodophors are good surface low-level disinfectants and good antiseptics.

A

False: they are intermediate level disinfectant and yes they are good antiseptics

98
Q

The primary activity of chlorine-containing compounds (bleach) is _______.

A

antimicrobial activity by oxidation = unfolding of proteins

99
Q

True or False: Biofilms form in all water lines.

A

True

100
Q

Small diameter lines used in dental units have _____ surface-to-volume ratios.

A

greater

101
Q

True or False: Using sterile water will help to prevent biofilm formation.

A

False

102
Q

Which two pathogens are commonly associated with waterline biofilms?

A

Pseudomonas
Legionella
May put immunocompromised at risk

103
Q

What is the EPA standard for biofilms/microbial counts and safe waterlines?

A

less than or equal to 500 CFU/mL

104
Q

Biofilms are resistant to treatment; however, regular flushing of waterlines with _______ will help keep lines within healthy limits. What is another benefit to using this chemical for flushing waterlines?

A

chlorhexidine

it is not toxic, any residual will not cause any issues for the patient

105
Q

It is recommended that lines be flushed for how long?

A

20-30 seconds before and after each patient

106
Q

Gloves do not provide a perfect barrier against microbes, therefore it is important that we protect ______ integrity and avoid _______ or _______ nails.

A
epithelial integrity (avoids scrapes and cuts)
artificial or long nails
107
Q

True or False: Alcohol-based hand rubs are recommended for routine decontamination of hands for all clinical indications except when hands are visibly soiled.

A

True

108
Q

What is substantivity?

A

when antiseptic hand cleansers are used repeatedly, they may provide a residual effect due to accumulation on epithelial tissues

109
Q

True or False: There are concerns about the safety of triclosan.

A

True

110
Q

When is hand-washing the preferred means of cleansing?

A
  1. when visibly soiled
  2. after using toilet
  3. if exposed to spore-forming pathogens, especially Clostridium difficile
111
Q

How long must alcohol rubs remain on hands?

A

20-30 seconds

112
Q

How long must hands be washed with soap and water for proper technique?

A

40-60 seconds