"Robert Wańkowski" <r...@w...pl> wrote in message
news:jh59md$7gb$1@inews.gazeta.pl...

po angielsku - ale dosc dobre streszczenie



Sterilization and Disinfection of Dental Instruments According to the
Centers for Disease Control, dental instruments are classified into three
categories depending on the risk of transmitting infection. The
classifications of critical, semicritical and noncritical are based on the
following criteria:


1) Critical instruments are those used to penetrate soft tissue or bone, or
enter into or contact the bloodstream or other normally sterile tissue. They
should be sterilized after each use. Sterilization is achieved by steam
under pressure (autoclaving), dry heat, or heat/chemical vapor. Critical
instruments include forceps, scalpels, bone chisels, scalers and surgical
burs.

2) Semi-critical instruments are those that do not penetrate soft tissues
or bone but contact mucous membranes or non-intact skin, such as mirrors,
reusable impression trays and amalgam condensers. These devices also should
be sterilized after each use. In some cases, however, sterilization is not
feasible and, therefore, high-level disinfection is appropriate. A
high-level disinfectant is registered with the U.S. Environmental Protection
Agency (EPA) as a "sterilant/disinfectant" and must be labeled as such.

3) Non-critical instruments are those that come into contact only with
intact skin such as external components of x-ray heads, blood pressure cuffs
and pulse oximeters. Such devices have a relatively low risk of transmitting
infection; and, therefore, may be reprocessed between patients by
intermediate-level or low-level disinfection. An intermediate-level
disinfectant is EPA-registered as a "hospital disinfectant" and will be
labeled for "tuberculocidal" activity (e.g., phenolics, iodophors, and
chlorine-containing compounds). A low-level disinfectant is EPA-registered
as a "hospital disinfectant" but is not labeled for "tuberculocidal"
activity (e.g., quaternary ammonium compounds). The tuberculocidal claim is
used as a benchmark to measure germicidal potency. Germicides labeled as
"hospital disinfectant" without a tuberculocidal claim pass potency tests
for activity against three representative microorganisms: Pseudomonas
aeruginosa, Staphylococcus aureus, and Salmonella choleraesuis


Processing Instruments

All critical and semicritical dental instruments that are heat stable should
be sterilized after each use by steam under pressure (autoclaving), dry
heat, or chemical vapor. Before sterilization or high-level disinfection,
instruments should be cleaned so that any debris is removed. Enzymatic and
non-enzymatic solutions facilitate instrument cleaning. Heavy-duty gloves
should be worn when handling contaminated instruments. Instruments should
soak in water or disinfectant/detergent as soon as possible after use to
prevent drying of debris. Instrument cassettes and mechanical cleaning
(e.g., ultrasonic cleaners) may be used to reduce direct handling of
contaminated instruments. Applying rust inhibitors will protect instruments
from corrosion that may result from autoclaving. Packaging rinsed and dried
instruments before sterilization protects them from contamination after they
are removed from the sterilizer and during transport chairside or to
storage.]

Sterilization is recommended for all high-speed dental handpieces, low-speed
handpiece
components used intraorally and reusable prophylaxis angles. It is important
to follow the
manufacturers' instructions for cleaning, lubrication and sterilization
procedures to ensure
the effectiveness of the sterilization process and the longevity of these
instruments. Highspeed
and low-speed handpieces produced today are heat tolerant, and many older
heatsensitive
models can be retrofitted with heat-stable components.
Biological Indicators. Proper functioning of sterilization cycles should be
verified by
periodic use of spore tests called biologic indicators. Biologic indicators
consist of highly
resistant bacterial spores of Bacillus (Geobacillus) stearothermophilus
(used to monitor
steam and unsaturated chemical vapor sterilizers) or Bacillus subtilis (used
for monitoring
the dry heat sterilizer).
The CDC recommends that all sterilized implantable devices be quarantined
until the results
of biological monitoring are known.
Chemical Indicators. Chemical indicators (in the form of tape, strips, tabs
and special
markings on packaging material) indicate exposure to heat. Heat-sensitive
chemical
indicators that change color after exposure to heat do not guarantee
sterilization but should
be placed inside each pack, and on the outside of each pack when the
internal indicator is
not visible from the outside, to identify packs that have been processed
through the heating
cycle. Chemical indicators also should be placed in the center of a load of
unwrapped
instruments.
Flash Sterilization. Flash sterilization is a method for sterilizing
unwrapped instruments for
immediate use. This cycle operates at a higher temperature for a shorter
period of time than
the normal sterilization cycle. The CDC* recommends that flash sterilization
not be used
routinely in the dental office to sterilize patient instruments-this process
should only be
used in unavoidable situations.
"Cold Sterilization." In all dental and other health-care settings,
indications for the use of
liquid chemical germicides to sterilize instruments (i.e., "cold
sterilization") are limited. For
heat-sensitive instruments, this procedure may require up to 10 hours of
exposure to a liquid
chemical agent registered with the EPA as a "sterilant/disinfectant."
Instruments sterilized in
this manner should be rinsed with sterile water, dried and placed in a
sterile container (if not
used immediately).
Contact time is the single important variable distinguishing the
sterilization process from
high-level disinfection with FDA-cleared liquid chemical sterilants. The FDA
defines a "highlevel
disinfectant" as a sterilant that is used under the same contact conditions
as
sterilization except for a shorter immersion time.