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Clean? Disinfect? Sterilize?
What does it all mean??
DA 116 Infection Control
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Instruments, supplies, equipment, surfaces
After each patient treatment procedure is completed
Clean? (“pre-clean”)
• Basic first step of decontamination process
– Reduce the number of microbes and remove bioburden
– Prevent debris from harboring microorganisms during sterilization
process
**if a surface is not
CLEAN
it cannot be disinfected**
• Remove all disposables and contaminated items from operatory first
• Use soap and water OR an EPA-registered product that cleans and
disinfects
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Pre-Cleaning the operatory
• PPE with utility gloves
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Pre-Cleaning Instruments
preferred method: mechanical cleaning
Ultrasonic Cleaner
Instrument Washer
Disinfect?
• After precleaning
• NOT the same as sterilization
• Kills most disease-causing microorganisms, but not
spores
– Non-pathogenic microorganisms may remain on an object
after disinfection
• Use an EPA-registered hospital disinfectant with
tuberculocidal, HIV, and HBV claims
– Note: Hydrogen Peroxide is NOT an acceptable disinfectant
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Levels of Disinfection:
• Low level disinfection: (actually cleaning)
– Least effective. Does not kill spores or Tuberculosis
• Intermediate level disinfection:
– Kills TB, which is the most difficult to kill as spores
– If you use a process that kills TB spores, you will also be able to
kill other organisms that are easier to kill (HBV and HIV)
• High level disinfection:
– Kills some, but not all bacterial spores, including TB as well as
other bacteria, fungi and viruses
• Almost as effective as true sterilization but not as thorough
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Disinfectant Comparisons
note: rubbing alcohol is NOT an approved disinfectant
Disinfectant
Level
Advantages
Disadvantages
Required times
Glutaraldehyde
High
disinfect
impressions
Corrosive
Eye irritation
10-90 min.
Iodophor
Intermediate
Fast acting
Residual activity
discoloration
10 min on
surface
Skin/mucous
irritation
No use on plastics
10 min
Corrosive, skin
irritation, must
prepare daily
2-10 min
Cleans and disinfects
Complex
(synthetic)
Phenolics
Intermediate
Chlorines
Intermediate
Fast acting
Residual activity
Clean and disinfect
economical
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Disinfecting Sprays
How to Use:
For surface disinfection – use the 2
step method.
• Clean by wiping surfaces thoroughly
with disinfectant and paper towels or
4 x 4 gauze to remove all soils.
• Disinfect by reapplying disinfectant,
keeping surfaces wet for 10 minutes.
Wipe off excess solution after contact
time is completed. Place barriers.
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Disinfecting wipes
How to Use:
For surface disinfection – use the 2 step
method.
• To clean, remove one or more wipe
towelettes and wipe surfaces
thoroughly to remove all soils. Discard
used wipe towelettes.
• Remove one or more additional fresh
wipe towelettes. Reapply
disinfectant to previously cleaned
surfaces for a 10 minute contact time.
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Additional Disinfecting Concerns:
Radiography
• Film holders and positioners
for digital radiographs should
be heat sterilized between
patients, UNLESS they are
disposable items.
• Sensors for digital radiographs
cannot be sterilized and should
be covered with a new barrier
sleeve for each patient.
Dental Lab
• All items used in the mouth
should be cleaned and
soaked in a high level
disinfectant before sending
to the laboratory for
processing.
Sterilize?
– Process by which all forms of life are completely destroyed
• destroys all living microorganisms, including bacterial spores and
viruses. Kills good and bad microorganisms, all life
– After proper sterilization, no microorganisms will be alive
– Heat or Liquid Chemical
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Steam under pressure
Steam (autoclave)
Flash (Statim)
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Rapid Heat Sterilization
• AKA ‘Statim’
• Works like a convection oven, high temperature plus
circulating steam
• 375 F degrees (190C) 12 minutes for wrapped items
• 375 F degrees (190C) 6 minutes for unwrapped items
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Autoclave:
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Uses moist heat to sterilize
Steam under pressure is considered the sterilizing agent
15 pounds of pressure per square inch
250 degrees F (121 degrees C)
For 15-20 minutes for wrapped instruments
30 minutes for porous materials
Avoid overloading or wrapping instruments too tightly
Steam must circulate to all surfaces
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Chemical Vapor Sterilizer
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Chemical Vapor Sterilization:
• Combination of heat and unsaturated chemical vapor
(produces hot vapors of alcohol and formaldehyde that act as
sterilizing agent)
• Chemicals used: alcohol, acetone, ketone, formaldehyde and
distilled water
• Advantage:
– No corrosion or dulling of instruments
– Instruments are dry at end of cycle
– All instruments which can be autoclaved, can be chemiclaved
• Disadvantage: needs well ventilated area due to odor
• 270 F degrees (131C) 20-40 minutes 20 PSI pressure
• Clean, rinse and dry instruments well before sterilizing; wrap
loosely
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Dry Heat Sterilizer
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Dry Heat Sterilization:
• “Baking” – high temperature is sterilizing agent
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320 F degrees (160C degrees) = 2 hours (120 minutes)
340 F degrees (170C degrees) = 1 hour (60 minutes)
Advantage: no rust or corrosion or dulling sharp edges
Disadvantage: some plastics, gauze, impression trays cannot
tolerate high temperatures, can cause damage
• Instruments must be clean and dry prior to sterilization
• Usually requires special metal instrument trays used during
sterilization
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Glass Bead Sterilizer
Ethylene Oxide Sterilizer
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Glass Bead Sterilizer:
• *no longer OSHA accepted
• Previously used chairside
during endodontic procedures
to sterilize files between canals
– used on the same patient
• Consists of glass beads, metal
beads and salt
• 450 degrees F, for 20-30
seconds
• The set of files are then
autoclaved between patients
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Ethylene Oxide Sterilizer
• This is another chemical
sterilization method
• Considered a poisonous
gas
• Runs on a 10-16 hour
cycle
• Used in hospitals but not
in dental settings
Liquid Sterilant
(cold sterilant or
high-level disinfectant)
• Glutaradehyde product
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Liquid Sterilants:
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AKA “Cold Sterilants”
Destroys all microorganisms IF exposed long enough to the sterilant
Disadvantage:
– Time consuming (10 – 16 hours)
– No bacterial spore test available; May use a color monitor dip stick to test the
strength
– Whenever new item is added, time is reset to ten hours
– Toxic chemicals: glutaraldehyde;
• do not leave container uncovered
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Advantage:
– No packaging; will not harm heat sensitive items
Clean and dry everything before immersion; any water will dilute solution and lower
effectiveness
After cycle, must rinse with sterile water; dry with clean towels, and wrap in clean
packaging
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Sterilization Monitoring
– Biological monitoring with
spore tests:
Liquid Disinfectant Monitoring: color
monitor dip stick
(not a spore test)
• Process indicators