DENT 1103 Unit 4

Sequential steps for instrument processing

1. transport

2. cleaning (pre-cleaning)

3. packaging

4. sterilization

5. storage

6. delivery

7. quality assurance program

Transport step for instrument processing

- contaminated instruments transported to processing area in a way that minimizes the risk of exposure to persons using proper PPE

Instruments are transported to --> contaminated area

- disposable items are disposed as contaminated waste

Cleaning step for instrument processing

Removes as must bioburden as possible

- done with hands-free mechanical process (ultrasonic cleaner or instrument washer

If they cannot be cleaned immediately use holding solution

- thoroughly cleaning all visible contaminated before sterilization 

- hand scrubbing is the least desirable method

Packaging step for instrument processing

- instruments packaged in contaminated area with chemical indicator placed inside packaging

- instruments are dry (using lint free cloth if wet)

Sterilization step in instrument processing

- kills all microbes

- follow manufacturer's instructions 

- never overload sterilizer, place packages on edges in single layers or racks to increase circulation of steam around instruments

Storage step for instrument processing

- store sterilized packages in clean dry environment 

- rotate so oldest sterilized dates be used first

Delivery step for instrument processing

- deliver to point of use in a way that maintains sterility of instruments

- open package in front of client

Quality assurance program for instrument processing

- includes training, record keeping, maintenance, and use of biologic indicators

- records of equipment maintenance checks, biological spore tests

- exposure incidents must be recorded 

Ideal processing/ sterilization room

- centrally located and easy access from all client care areas

- dedicated only to instrument processing

- should not be part of common walkway (not have a door or window that opens to the outside)

- good air circulation

- air line ad vacuum line for flushing high-speed handpieces

Workflow pattern for processing instrumnets

Should be processed in a single loop:

dirty --> clean --> sterile --> storage , without doubling back 

Areas for processing isntrumnets

1. contaminated area

2, packaging area

3. sterilizing area

Contaminated area

the initial receiving area

- instruments are held here for processing 

- cleaning done here before disinfection and sterilizing (use holding solution if can't be cleaned immediately)

Items in contaminated area

utility gloves, counter space, sink, waste disposal container, holding solution, ultrasonic cleaner (use gown while in use), eye wash station

Packaging area

arrange set ups & wrapping instruments before sterilizing, insert indicators in packaging

Items in packaging area

lint free cloths, supplies for wrapping, indicator strips

Sterilizing area

"clean" area where packages are sterilized and packs are stored and assembled on trays

Items in sterilizing area

sterilizers, record keeping, fresh disposable supplies

Equipment located in contaminated area

- holding solution

- pre cleaning instrument methods (items for hand scrubbing, ultrasonic cleaner)

- automated washer

Holding solution use

used only if contaminated instruments can't be cleaned/processed immediately after procedure

Holding solution function + aspects

- prevents drying of blood and debris on instruments 

- non-corrosive liquid (may use dishwasher detergent)

- container must be lid and labelled biohazard and chemical 

- changed at least twice daily or more frequently if cloudy

Hand scrubbing

method of pre-cleaning instruments

- least desirable method requiring direct contact with contaminants

- goggles and gloves must be used

Precautions for hand scrubbing

- clean only one or two instruments at a time (use long-handled brush)

- ensure you can see sharp ends when scrubbing

Ultrasonic cleaner

method of pre-cleaning instruments

- uses ultrasonic sound waves that cause cavitation (bubbles) that when they burst by implosion, they remove debris from instruments

- instruments should be processed until they are visibly clean (10-15 mintues)

Care for ultrasonic cleaner

- solution affects the function, must be discarded at least once a day: have an automatic drain eliminating contact to pour contaminated solution in sink

Solution for ultrasonic cleaner

- always refer to manufacturer's instructions 

- some have antimicrobial activity preventing build-up of microbes but doesn't disinfect instruments

- do not use other chemicals like disinfectants which can fix blood and debris onto instruments 

- must be discarded at least once a day or sooner

Automated washer

- the first place contaminated instruments go, like a dishwasher

- combination of very hot water and detergent to remove organic material

- classified as thermal disinfectors - machine has disinfecting cycle that subjects the instruments to a level of heat that kills most microorganisms 

- come out thoroughly dry, use lint free cloth if not

- instruments are then wrapped and sterilized

Procedures performed in packaging area 

First load of the day: PCD with Biological monitoring

- packaging instruments 

- process indicators

PCD

process challenge device

- used in the first load of the day for sterilizer placed in the hardest to each place indicated by manufacture

- contains class V indicator and biological indicator

Biological monitoring

spore test - the only way to determine if sterilization has occurred and all bacteria and endospores have been killed

- used in the first load of the day inside PCD and is done daily

- want a negative result: spores have been killed sterilization was successful

Packaging instruments 

done to protect them from becoming contaminated after sterilization 

- materials: bags, paper wraps, indicator tape, monitoring strips

Unpackaged sterilized instruments

prone to becoming contaminated

Process indicators

Can be physical, chemical, and biological

Physical monitoring

Looking at gauges and readings

- temperature recorded is for chamber not inside pack

Chemical monitoring

Use heat-sensitive chemical that changes colour when exposed to certain conditions

- Process integrators 

- Process indicators

Process integrators for chemical monitoring

Inside the instrument packages responding to combination of pressure, temperature and time

- assures sterilizing agent penetrated package

Process indicators for chemical monitoring

Outside instrument packages, identifying if they've been exposed to certain temperature, not measuring duration or pressure

ex. tape and colour-change markings on packages

Various forms of instrument sterilization

- Steam sterilization - autoclave

- Chemical vapour

- Dry heat

- Liquid chemical immersion

Steam sterilizer autoclave

sterilize by steam under pressure - heating water to generate steam, producing moist heat that rapidly kills microorganisms: cool air is pushed out as steam fills chamber and pressure increases

- temperature: 121 decrees C

Packaging for items inside steam sterilizer autoclave

- Packaging must be porous enough to allow penetration of steam

- Cannot use solid closed trays - limits penetration of heat 

- Use distilled water: tap water has minerals that can corrode 

Advantages of steam autoclave sterilizer

- quick and reliable (cycle ranges from 3-30 minutes)

- allows for packages or wraps 

- steam penetrates fabrics and paper

Disadvantages of steam autoclave sterilizer

- may rust and corrode items

Chemical vapour (chemiclave)

- Chemicals used instead of water to create vapour for sterilizing 

- Paper packaged items only, no closed container (limits penetration of heat)

Not acceptable in Canada

Advantages of chemical vapour

- does not rust, dull or corrode metal instruments 

- large range of items can be sterilized 

Disadvantages of chemical vapour

- requires special solution increasing cost 

- fumes from vapour require good ventilation

- damages some plastics

- takes 20-40 minutes

Dry heat sterilizing

- sterilization by conduction: direct contact with heat source
can be static air and forced air 

Static air in dry heat sterilizing

Like an oven heating coil on bottom of chamber and hot air rises

heat transferred from static (non-moving) air to instrument in 1-2 hours

Forced air for dry heat sterilizing

Circulates hot air throughout chamber at high velocity 

Rapid transfer of heat energy from air to instrument

Advantages of dry heat sterilizing

- easy to use

- no rust or corrosion

Disadvantages of dry heat sterilizing

- longer sterilization cycles and times 

- higher temperature than steam of chemical vapour 

- damages plastics, can burn fabric and paper 

- wrapping material must be heat resistant

Liquid chemical immersion sterilants (cold soak)

sterilization by liquid chemical soaking - chemical must be EPA registered high level disinfectant/sterilant

Advantages of liquid chemical immersion sterilants

May sterilize heat sensitive items - rubber dam frames, x-ray film holders

Disadvantages of liquid chemical immersion sterilants

- instruments/items must be completely immersed for up to 10 hours

- impossible to determine diminished solution (limited use life)

- solution must be prepared daily

- creates toxic film

- items must be rinsed with sterilized water then packaged and dried with sterile globes and towel

- process cannot be verified with biological indicator

Causes of failed sterilization of instruments

- inadequate instrument cleaning

- improper packaging

- improper loading of sterilizer

- improper timing/ temperature

Dried blood remaining on instrument

fails to sterilize instruments because of inadequate instrument cleaning

- organisms insulated from sterilizing agent

Excessive wrap

fails to sterilize instruments because of improper packaging

- prevents sterilizing agent from penetration

Cloth wrap in chemical vapour sterilizer

fails to sterilize instruments because of improper packaging

- absorb chemical needed for sterilization

Closed container in steam/chemical vapour

fails to sterilize instruments because of improper packaging 

- prevents direct contact with sterilizing agent

Overloading packages

fails to sterilize instruments because of improper loading of sterilizer

- closes down penetration increasing time for heat to reach

Packages too close together

fails to sterilize instruments because of improper loading of sterilizer

- prevents sterilizing agent from reaching all items

Error in timing/ interrupted cycle

fails to sterilize instruments because of improper timing/ temperature

- inssufficient time to sterilize

Proper handling and storage of sterilized instruments

- only handle cool dry packages from sterilizer 

- handle packages as few times as possible 

- packages that are torn or wet should be repackaged and reprocessed 

- avoid crushing, bending, or compression of packages

do not handle or remove wet packages