Infection Control- Ch 21 Test/COMPLETE

Autoclave

equipment for sterilization by means of moist heat under pressure

biological indicators

vials or strips, also known as spore tests, that contain harmless bacterial spores; used to determine whether sterilization has occurred 

biological monitoring

verifies sterilization by confirming that all spore-forming microorganisms have been destroyed

chemical vapor sterilization

sterilization by means of hot formaldehyde vapors under pressure

clean area

place where sterilized instruments, fresh disposed supplies, and prepared trays are stored

contaminated area

place where contaminated items are brought for precleaning

critical instrument

instruments that penetrate soft tissue or bone

dry heat sterilization

Sterilization using heated air without moisture to kill microorganisms.

endospores

resistant, dormant structures formed inside of some bacteria that can survive extreme conditions.

event related packaging

instruments in packages should remain sterile indefinitely unless an event causes them to become contaminated, such as damage to the packaging or wet packaging.

multiparameter indicators

Strips placed within packaging that change color when exposed to heat, temp, time. The device is used to monitor multiple things at once such as temperature, time, and sterilization success.

noncritical instrument

item that comes in contact with intact skin only

process indicators

tabs, strips, and tapes have heat sensitive chemicals that change color when exposed to a certain temperature

process integrators

strips placed in packages that monitor sterilization parameters beyond just temperature, such as time and pressure, to ensure proper sterilization conditions are met.

Safety data sheet

OSHA’s newer term for Material Safety Data Sheet (MSDS), they are required for each hazardous chemical in a facility

semi-critical instrument

item that comes in contact with oral tissue but does not penetrate soft tissue or bone

single parameter indicator

tapes, strips, or tabs that change color when exposed to a specific temperature to verify that specific sterilization conditions, such as temperature, have been met.

ultra sonic cleaner

equipment that loosens and and removes debris by sound waves traveling through a cleaning solution, effectively cleaning instruments.

use life

period of time during which a germicidal solution is effective after it has been prepared for use

wicking

process of microorganisms being drawn through wet or damp paper packaging, contaminating the instrument inside

Sterilization

kills all microorganisms

Classification of Instruments

Critical instruments

• Penetrate soft tissue or bone

• Greatest risk of transmitting infection

• Must be sterilized by HEAT

Semi-critical instruments

• Touch mucous membranes or nonintact skin

• Lower transmission risk

• Sterilized by heat or receive minimum high-level disinfection if not heat tolerant

• Example: Amalgam Carriers, dental dam forceps

Noncritical instruments

• Contact only intact skin

• Low risk of infection transmission

• Cleaned and processed with EPA-registered intermediate- or low-level disinfectant

• Example: Xray unit tube head, lead apron and curing light.

Personal Protective Equipment (PPE)

ALWAYS WEAR PPE when processing instruments

This includes utility gloves, mask, eyewear, and protective clothing

Seven Steps for Instrument Processing

1. Transport-transport contaminated instruments

2. Cleaning-clean instruments

3. Packaging-wrap/package instruments

4. Sterilization-load sterilizer according to directions

5. Storage-store clean instruments

6. Delivery-delivery instruments to point of use

7. Quality-an effective quality assurance program

Instrument-Processing Area

Centrally located allows for easy access from all patient care areas

Dedicated only to instrument processing

Physically separated from operatories and laboratory

Not be part of a common walkway

Workflow Pattern

Four basic areas govern the pattern of workflow

Processing of instruments should proceed in a single loop, from dirty to clean to sterile to storage, without ever “doubling back”

If the instrument-processing area is small, you can use signs that read:

“Contaminated items only”

“Precleaning area”

“Cleaned items only”

“Sterile items only”

Contaminated Area

All soiled instruments brought into the contaminated area, the initial receiving area, held for processing

• Any disposable items are removed from the instrument tray and disposed of as contaminated waste

Thorough cleaning done before all disinfection and sterilization processes

• Removal of all debris and organic materials (e.g., blood and saliva)

Contaminated area contains clean protective eyewear and utility gloves, counter space, a sink, a waste disposal container, holding solution, an ultrasonic cleaner, an eyewash station, and supplies for wrapping of instruments before sterilization

Preparation and Packaging Area

Area where cleaned instruments and other dental supplies are inspected, assembled into sets or trays, and wrapped or placed in packages for sterilization

Clean instruments are not sterile and could harbor pathogens

• Instruments must be packaged and sterilized before used on a patient

Precleaning and Packaging Instruments

Instruments may be precleaned in one of three ways

• Hand scrubbing

• Ultrasonic cleaning

• Instrument-washing machine

Holding Solution

If not cleaned immediately after a procedure, place them in a holding solution to prevent the drying of blood and debris on the instruments

The holding solution is a noncorrosive liquid

• A commercial enzymatic solution

Dishwasher detergent also makes a good holding solution: low-cost, low-foaming, and readily available

It is neither cost-effective nor desirable to use a disinfectant alone as a holding solution

Holding Solution

The container with a lid and must be labeled with:

• A biohazard label (because of the contaminated instruments)

• A chemical label (because of the cleaner/detergent)

Holding solution should be changed at least twice daily, and even more frequently if it becomes clouded

Remember, holding solution is necessary only when contaminated instruments cannot be processed immediately

Precleaned by: Hand Scrubbing

Hand scrubbing is the least desirable method of cleaning instruments-requires direct hand contact with the contaminated instrument

Precleaned by: Ultrasonic Cleaning

Used to loosen and remove debris from instruments

Reduces the risk of cuts and punctures to the hands during the cleaning process

WEAR: Puncture-resistant utility gloves, a mask, protective eyewear, and a protective gown

Keep a set of tongs near the ultrasonic unit; these can be used to remove instruments after the cleaning cycle has been completed

Ultrasonic Cleaner

Works by producing sound waves beyond the range of human hearing

Sound waves, which can travel through metal and glass containers, cause cavitation (formation of bubbles in liquid)

Bubbles burst by implosion

Instruments should be processed in the ultrasonic cleaner until they are visibly clean then rinsed with clear water.

Time varies from 5 to 15 minutes, depending on amount and type of material on the instruments and the efficiency of the ultrasonic unit

Ultrasonic Cleaning Solutions

Only use ultrasonic solutions that are specially formulated for use in the ultrasonic cleaner

Some ultrasonic cleaning products have enzyme activity

Other ultrasonic cleaning products have antimicrobial activity

Antimicrobial activity does not disinfect the instruments; prevents the microorganisms from multiplying

Testing the Ultrasonic Cleaner

If instruments are not being cleaned completely with processing in the ultrasonic cleaner, the unit may not be functioning properly

To determine whether the ultrasonic cleaner is working properly, hold a 5×5-inch sheet of lightweight aluminum foil vertically (like a curtain) half-submerged in fresh, unused solution

Run the unit for 20 seconds, then hold foil up to the light

Surfaces submerged are evenly marked with a tiny pebbling effect over the entire surface

An area without pebbling of more than ½ inch indicates a problem with the unit, and it needs to be serviced

Drying, Lubrication, and Corrosion Control

Instruments and burs made of carbon steel will rust during steam sterilization

Rust inhibitors such as sodium nitrate and commercial products can be used

An alternative is to dry the instrument thoroughly with the use of dry heat or unsaturated chemical vapor sterilization (discussed later), which does not cause rusting

Sterilization of Unwrapped Instruments

An unwrapped cycle (sometimes called flash sterilization) is a method for sterilizing unwrapped patient care items for immediate use

Unwrapped sterilization used only under certain conditions

Methods of Sterilization

Sterilization destroys all microbial forms, including bacterial spores

All reusable items (critical and semi critical instruments) that encounter the patient’s blood, saliva, or mucous membranes must be heat sterilized

The three most common forms of heat sterilization in the dental office are:

• Steam

• Chemical vapor

• Dry heat

Steam Autoclave Sterilization

An autoclave is used to sterilize by steam under pressure

Steam sterilization involves heating water to generate steam, producing a moist heat that rapidly kills microorganisms

It is actually the heat, not the pressure, that kills the microorganisms

Steam Autoclave Operation Cycles

Dental office steam sterilizers usually operate in four cycles

Heat-up cycle

Sterilizing cycle

Depressurization cycle

Drying cycle

Packaging Instruments for Steam Autoclave Sterilization

Packaging material is porous enough to permit steam to penetrate to the instruments inside

The packaging material may be fabric, sealed film or paper pouches, nylon tubing, sterilizing wrap, or paper-wrapped cassettes

One disadvantage of steam sterilization is that the moisture may cause corrosion on some high-carbon steel instruments

Distilled water should be used in autoclaves instead of tap water, which often contains minerals and impurities

Flash Sterilization

Rapid, or “flash,” sterilization of dental instruments is accomplished by means of rapid heat transfer, steam, and unsaturated chemical vapor

Flash sterilization may be used only on instruments that are placed in the chamber unwrapped

Flash sterilization should be for instruments that are to be promptly used on removal from the sterilizer

Unsaturated Chemical Vapor Sterilization

Chemical vapor sterilization is like autoclaving, except that a combination of chemicals (alcohol, formaldehyde, ketone, acetone, and water) is used instead of water to create a vapor for sterilization

OSHA requires a Safety Data Sheet (SDS) on the chemical vapor solution because of the chemicals’ toxicity

Advantages of Unsaturated Chemical Vapor Sterilization

The major advantage of the chemical vapor sterilizer is that it does not rust, dull, or corrode dry metal instruments

The low water content of the vapor prevents destruction of items such as endodontic files, orthodontic pliers, wires, bands, and burs

A wide range of items can be sterilized routinely without damage

Other advantages short cycle time and availability of a dry instrument after the cycle

Disadvantages of Chemical Vapor Sterilization

The primary disadvantage is that adequate ventilation is essential because residual chemical vapors containing formaldehyde and methyl alcohol may be released when the chamber door is opened at the end of the cycle

These vapors can temporarily leave an unpleasant odor and be irritating to the eyes

Dry Heat Sterilization

Operates by heating air and transferring that heat from the air to the instruments

This form requires higher temperatures than other forms of sterilization

Dry heat sterilizers operate at approximately 160º C to 190º C (320º F to 375º F), depending on the type of sterilizer

Advantage of dry heat: Instruments will not rust if they are thoroughly dry before being placed in the sterilizer

Two types: Static air and forced air

Liquid Chemical Sterilants

Some types of plastics, such as some rubber dam frames, shade guides, and x-ray film–holding devices, are damaged by heat sterilization

A liquid sterilant such as 2.0% to 3.4% glutaraldehyde must be used for sterilization of these items

Glutaraldehyde requires 10 hours of contact time; anything less than 10 hours is disinfection, not sterilization

Be sure you have an MSDS for these products

Liquid chemical sterilants CANNOT be poured down the sink, toxic for the sewer system.

Sterilization Failures

Sterilization may fail when direct contact for the correct time between the sterilizing agent (chemical or steam) and all surfaces of the items being processed is insufficient

Several factors cause the sterilization process to fail, including:

• improper instrument cleaning

• packaging and sterilizer malfunction

• Improper set time and temperature for sterilization

• Improper loading of the sterilizer

Sterilization Monitoring

It is critical that dental instruments be properly sterile

Three forms of sterilization monitoring are used

• Physical

• Chemical

• Biologic

Physical Monitoring

Looking at the gauges and readings on the sterilizer and recording temperatures, pressure, and exposure time

Although correct readings do not guarantee sterilization, an incorrect reading is the first signal of a problem

• Remember the reading reflects the temperature in the chamber, not inside the pack

Chemical Monitoring

Involves the use of a heat-sensitive chemical that changes color when exposed to certain conditions

There are two types of chemical indicators

• Process indicators

• Process integrators

Process Indicators

Process indicators (external) are placed outside the instrument packages before sterilization

• Examples: Autoclave tape and color-change markings on packages or bags

Process indicators simply identify instrument packs that have been exposed to a certain temperature

Process indicators are useful in distinguishing between packages that have been processed and those that have not

Process Integrators

Placed inside instrument packages

They respond to a combination of pressure, temperature, and time

Process integrators are also known as multiparameter indicators

All sterilization factors are integrated

Examples: Strips, tabs, or tubes of colored liquid

The advantage of placing integrators inside each package is that penetration of the packaging by the sterilizing agent is ensured

Limitations of Process Integrators

Process indicators and integrators provide immediate visual control of sterilizing conditions

They do not indicate sterility and are not a replacement for biologic monitoring

Biologic Monitoring

Biologic monitoring (spore testing), is the only way to determine whether sterilization has occurred, and all bacteria and endospores have been killed

The CDC, American Dental Association, and Office of Safety and Asepsis Procedures Research Foundation recommend at least weekly biologic testing of sterilization equipment

Biologic Indicators (BIs)

Also known as spore tests, biologic indicators (BIs) are vials or strips of paper that contain harmless bacterial spores (which are highly resistant to heat)

Three BIs are used in testing

• Two BIs are placed inside instrument packs, and the sterilizer is operated under normal conditions

• The third strip is set aside as a control

After the load has been sterilized, all BIs are cultured

If the spores are killed (a negative result), the sterilization cycle was successful. Report will be mailed to the office from the monitoring service.

If the monitoring system calls with a positive result indicates the sterilization failed.

The culturing of the spore test is usually handled with the use of a mail-in monitoring service

Handpiece Sterilization

High-speed dental handpieces rotate at speeds up to 400,000 revolutions per minute (rpm)

Blood, saliva, and tooth fragments, as well as restorative materials, may lodge in the head of the handpiece, where they may be retained and transferred to another patient

Dental handpieces must be properly cleaned and recommended heat-(steam) sterilization

Handpiece Flushing Techniques

Flushing the handpiece is the best way to remove debris from the head

To flush a dental handpiece:

• Attach a pressurized handpiece cleaner to the intake tube of the handpiece

• Flush the head of the handpiece for 10 to 20 seconds

• Blow out the handpiece using compressed air

Running coolant water from the dental unit through the handpiece at chairside is insufficient

Handpiece Sterilizing Techniques

Only steam sterilization and chemical vapor sterilizers are recommended because sterilization temperatures should not exceed 275º F (135º C)

Handpieces should be packaged in bags, wraps, or packs to protect them from contamination before use

Never run a handpiece “hot” out of the sterilizer, and avoid rapid cool-downs, such as running the handpiece under cold water

If handpieces need to be cooled quickly after sterilization, use an air fan to blow room-temperature air over them

What combination of factors produces the greatest amount of rusting and dulling of instruments?

non-stainless steel instruments in a steam sterilizer

What is the first step to be taken after a sterilization failure is detected by use of a biologic indicators?

take the sterilizer out of service

Biologic monitoring is also known as _________testing.

spore testing

What is the major advantage of forced air sterilizers over the other types of sterilizers?

short sterilization cycle time

What is the major disadvantage of using a chemical vapor?

adequate ventilation and or purging of the cycle

Which of the following errors will NOT result in a failure of sterilization?

failure to use a process indicator

The minimum frequency recommended by the CDC, ADA, and OSAP for the biologic monitoring of all the sterilizing equipment is:

weekly

Some ultrasonic cleaning solutions have

enzymatic activity

Devices used for instrument sterilizations must be:

able to achieve a temperature of 270F

The purpose of use of a holding solution before instrument sterilization is to:

prevent blood and debris from dying on the items.

Patient care items that penetrate soft tissue, such as scalers and curettes, have the highest risk of transmitting infection and are classified by the CDC as:

critical

Instrument packs must always be allowed to dry before handling, because the wet paper may tear and the

paper may draw or "wick" microorganisms into the package

Recommended methods of sterilizing dental handpieces include

steam sterilization

A monitoring service will immediately communicate a failure of sterilization through:

a telephone call to the dental office, reporting a positive result

A type of sterilization used in the dental office that requires the highest temperature is

dry heat sterilization

To help prevent rust or corrosion of items in a steam autoclave, the instruments should be ______before they are placed in the autoclave.

dried

Flash sterilization can be achieved in a steam autoclave by__________.

placing only unpackaged items in the sterilizer

The major advantage of the chemical vapor sterilizer is that:

it does not rust, dull, or corrode dry metal instruments

Drying instruments used in the dental office that requires the highest temperature is________.

steam

A method of sterilizing unwrapped patient care items for immediate use is__________.

flash sterilization

What should be done to instrument packages just before they are opened for use on the patient?

check them for tears or punctures

Which of the following statements is true regarding the seven steps for instrument processing?

sterilization takes place prior to storage

In the sterilization process, a process INDICATOR is an example of __________monitoring

external chemical

The appropriate parameters for unsatuarated chemical vapor sterilization are______________.

20 minutes at 270 F

Which method of precleaning instruments is the least desirable?

hand scrubbing