Sterilization, Disinfection, and Antisepsis Flashcards
True or False: Most human pathogens have been isolated from oral secretions.
True
What are the four (five) routes for transmission of disease during dental treatment?
- Direct
- Indirect
- Spatter
- Aerosolization
- Fomites
What is direct transmission?
contact with the infectious lesion, saliva, or blood
What is indirect transmission?
transmission via contaminated intermediate objects
What is spatter?
droplets of blood, saliva, plaque, or nasopharyngeal secretions
What is a fomite?
a germ on an inanimate object (i.e. on charts in the chart room)
What is the difference between spatter and aerosolization?
spatter = droplets Aerosol = small, floating particles
_____ is a pathogen that was named after a river in the Congo where it was first recognized in 1976.
Ebola
What is the fatality rate of Ebola?
50%
True or False: Increased age is associated with a higher mortality rate of Ebola.
True
How infectious is Ebola?
HIGHLY infectious, a SINGLE virus may be enough
What is the difference in Ebola’s infectiousness and contagiousness?
Highly infectious: single viron
Moderately contagious: NOT transmitted through the air
How is Ebola tranmitted?
direct contact with body fluids or contaminated objects from infected persons
What is the incubation period of Ebola?
2 to 21 days
True or False: Ebola is not contagious until symptoms develop.
True
Is Ebola enveloped or non-enveloped? How does this effect its ability to be killed?
enveloped
the lipid membrane is susceptible, therefore it can be killed by alcohol or hand sanitizer
True or False: the risk of transmitting HIV from patient to health care worker is very high.
False
True or False: The risk for transmitting Hepatitis B if very low.
False!!!
Epidemic resurgence of ______ is related to the immigrant population.
Tuberculosis
How is tuberculosis transmitted?
Coughing of infective aerosols followed by subsequent inhalation
______ _______ type I and II are frequently present in the oral cavity, may be transmitted to healthcare workers, and may cause blindness.
Herpes Simplex
What is viral whitlow?
herpetic lesion on the finger (may transmit virus from healthcare worker to patient via this lesion)
Which immunizations are recommended for healthcare personnel?
Hep B
Flu
MMR
Varicella Zoster
What are “critical” items?
items that come into contact with tissues or the vascular system (i.e. burs and endo tools)
What are “semi-critical” items?
items that come into contact with mucous membranes or non-intact skin (i.e. curing lights)
What are “non-critical” items?
items that touch in tact skin (i.e. blood pressure cuff)
What is sterilization?
destruction or removal of all life forms INCLUDING SPORES
Sterilization can only be used on _____ objects and can be via ____ or ____ means.
inanimate
heat or chemical
What does it mean to disinfect?
to inhibit or destroy pathogens without killing spores; used only on inanimate objects
What are antiseptics used for?
to destroy pathogenic microorganisms on living tissues; they are safe for use on human tissue
True or False: Antiseptics and disinfectants can be used interchangeably.
False
The FDA regulates liquid chemical sterilants used on ____ and ____ items; whereas, the EPA regulates chemical disinfectants that are used on _______ surfaces and gaseous sterilants.
Critical and semicritical
noncritical
What are the three levels of disinfection?
High-level
Intermediate-level
Low-level
High-level disinfection destroys __________, with the exception of _________.
all microorganisms
bacterial spores
Intermediate level disinfection will inactivate Mycobacterium _________, vegetative bacteria, most ____, and most _____ but does not necessarily kill bacterial spores.
tuberculosis
viruses
fungi
Why are disinfectants tested against M.tuberculosis when it is transmitted through the air?
Simply: it is a strong (hearty) bacteria that provides good results when used for testing
What do low-level disinfectants kill?
most bacteria
some viruses
some fungi
*will NOT kill M.tuberculosis or bacterial spores
Critical items must be _____ because any microbial contamination could transmit disease.
sterilized
Semicritical items should be ______ if possible; however, _____ or _____-level disinfection is absolutely required.
sterilized
high or intermediate
Why do noncritical items require only a low-level disinfectant?
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)
What are three methods for proper sterilization?
saturated steam under pressure
dry heat
unsaturated chemical vapor
Which method of sterilization is most efficient and reliable?
Heat; proteins are denatured by heat = kills the organism
True or False: Items do not need to be cleaned before sterilization, the high temperatures will melt away any excess debris.
False: must be cleaned or the bioburden may prevent sterilization
What is an autoclave?
the oldest, most commonly used method of sterilization, uses steam under pressure
What are the autoclave conditions? (temperature, pressure, time)
121 degrees Celsius (250 F)
15 psi
15-20 minutes
When using the autoclave, items must be packaged in material that allows for _______ which is at _____ psi.
penetration of steam
15
One advantage of the autoclave is the short cycle time; how long does it take?
15-20 minutes
True or False: Steam under pressure will penetrate faster than dry heat.
True
The autoclave sterilizes at _____ degrees Celsius or _____ degrees Fahrenheit.
121
250
What are the four main disadvantages of the autoclave?
- corrosion/dulling
- deposits
- remain wet at end of cycle
- destruction of heat sensitive materials
What is “flash steam sterilization”? Do we use this in the school?
Statim Brand:
its a smaller, more rapid, hotter, higher pressure unit for sterilization. Yes there is one in the dental coach.
How fast is the flash steam sterilization? Compare it to the autoclave.
6-12 mins
autoclave is 15-20
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?
dehydrated proteins are more stable, so dry heat requires HIGHER temperatures for LONGER time frames
Why must packages be kept somewhat underfilled during dry heat sterilization?
Heat transfer is very slow: you don’t want to overfill the oven or packages
What is the advantage to dry heat sterilizing?
does not corrode or dull cutting edges
Compared to the autoclave, dry heat sterilization requires ____ temperatures and ______ time.
higher (160 C for 2 hours, or 170 C for 1 hour)
longer
True or False: Dry heat sterilization is better for handpieces than the autoclave.
False: dry heat cannot be used for handpieces at all, therefore you would still need an autoclave too
_____ ______ transfer sterilization reduces time of cycling and does not corrode or dull instruments.
Rapid Heat (12 mins for wrapped items, 6 mins unwrapped)
What are the disadvantages to using Rapid Heat Transfer?
not suitable for handpieces
destruction is greater because the temperature is so hot (190 C, or 375 F)
______ ______ Vapor Sterilization depends on heat, water, and chemical synergy.
Unsaturated Chemical
Chemical vapor sterilization uses mixtures of methyl alcohol, _______, ketone, acetone, and water.
formaldehyde
Do instruments corrode with chemical vapor sterilization?
no
What is the main disadvantage to chemical vapor sterilization?
chemical odor and safety concerns; emissions
How long does chemical vapor sterilization take?
20-40 minutes (under 20psi)
Sterilization is ________ weekly in order to follow CDC and state law guidelines.
monitored
Treated tapes and heat sensitive strips are examples of ______ monitoring and indicate that items were heated.
chemical
True or False: Indicators ensure that temperatures were reached and maintained for adequate sterilization.
False: they only indicated that the item was heated; autoclave tape changes color long before sterilization conditions are met
______ indicators (monitoring) provide the BEST guarantee of sterilization.
Biological
What do biological monitors contain?
spores that are more resistant than most viruses or bacteria (NOT PATHOGENIC); ex. Bacillus stearothermophilus is used in autoclaves
What are the two forms of biological monitors?
Glass vials: contain spore suspension and pH indicator
Spore-impregnated Strips: sent to service for check
What do you look for in the glass vials of biological monitors?
color change
spores germinate and produce acid, the pH strip will change colors in response to the acid production
Do not use _____ sterilants in place of heat, only use when heat is not appropriate.
chemical
What is the common chemical sterilant that is used to irreversibly inactivate nucleic acids and proteins?
ETO (ethylene oxide)
ETO is ______!
explosive
ETO will burn tissue but some still use it because it does not _______.
damage heat or moisture sensitive materials
How long does ETO take?
10-16 hours at room temperatures (25 C, 75 F)
Which chemical is used most often, is considered to be the “most potent germicide,” and requires 10 hours of immersion in solution?
Glutaraldehydes
True or False: Glass bead sterilization is FDA approved.
False
What are disadvantages to using Glutaraldehyde solutions?
long immersion time allergenic tissue irritation fume toxicity corrosive to metals
Do not ______ if you can ______.
disinfect
sterilize
What kind of chemical disinfectant is used in CaviWipes?
quaternary ammonium alcohol
CaviWipes are _____-level disinfectants for ______ items.
intermediate
semicritical
What level disinfectant is Accelerated Hydrogen Peroxide?
intermediate
AHP is the newest product on the market, what are the main advantages to its use?
no odor
non-toxic
short contact time (1 min!!)
cleans and disinfects
Which disinfectants are considered to be “cytoplasmic poisons” due to their penetration and disruption of microbial cell walls and denaturing of intracellular proteins?
Phenols (toxic to tissue, don’t use as antiseptic = phe-NO NOs)
True or False: Phenols must be used in conjunction of another agent because it is a poor cleaning agent.
True
If using alcohols as a single agent of disinfection, it must be ______ % alcohol.
60-80%
Alcohols are considered _____ to ____-level disinfectants.
intermediate to low
True or False: Alcohol makes proteins insoluble and tenaciously adherent to surfaces which can protect microorganisms.
True
Detergents are ____-level disinfectants.
low
Detergents provide mechanical ______ and disrupt _______.
cleansing
some cell membranes
Gram _____ bacteria are more susceptible to antimicrobial effects of detergents.
positive
Let’s talk about charges (+/-): Detergents and soaps are _____, whereas quaternary ammonium solutions are _____.
anionic (not effective against gram negative, “opposites attract” is relevant here too)
cationic
Quaternary Ammonium is a _____-level surface disinfectant suitable for _____ items. However, Quaternary Ammonium-Alcohol Combinations are ____-level disinfectants.
low
noncritical
intermediate
True or False: A tincture of iodine is a good antiseptic against both gram positive and gram negative bacteria.
True
Which solution (iodine or iodophor) has these characteristics: less irritating, less allergenic, and longer acting?
iodophor
True or False: Iodine and iodophors are good surface low-level disinfectants and good antiseptics.
False: they are intermediate level disinfectant and yes they are good antiseptics
The primary activity of chlorine-containing compounds (bleach) is _______.
antimicrobial activity by oxidation = unfolding of proteins
True or False: Biofilms form in all water lines.
True
Small diameter lines used in dental units have _____ surface-to-volume ratios.
greater
True or False: Using sterile water will help to prevent biofilm formation.
False
Which two pathogens are commonly associated with waterline biofilms?
Pseudomonas
Legionella
May put immunocompromised at risk
What is the EPA standard for biofilms/microbial counts and safe waterlines?
less than or equal to 500 CFU/mL
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?
chlorhexidine
it is not toxic, any residual will not cause any issues for the patient
It is recommended that lines be flushed for how long?
20-30 seconds before and after each patient
Gloves do not provide a perfect barrier against microbes, therefore it is important that we protect ______ integrity and avoid _______ or _______ nails.
epithelial integrity (avoids scrapes and cuts) artificial or long nails
True or False: Alcohol-based hand rubs are recommended for routine decontamination of hands for all clinical indications except when hands are visibly soiled.
True
What is substantivity?
when antiseptic hand cleansers are used repeatedly, they may provide a residual effect due to accumulation on epithelial tissues
True or False: There are concerns about the safety of triclosan.
True
When is hand-washing the preferred means of cleansing?
- when visibly soiled
- after using toilet
- if exposed to spore-forming pathogens, especially Clostridium difficile
How long must alcohol rubs remain on hands?
20-30 seconds
How long must hands be washed with soap and water for proper technique?
40-60 seconds
