Asepsis Flashcards
Sepsis is
the breakdown of living tissue by the action of microorganisms
and is usually accompanied by inflammation.
Asepsis
refers to the avoidance of sepsis.
Medical asepsis
is the attempt to keep patients, health care staff, and
objects as free as possible of agents that cause infection.
Surgical asepsis
is the attempt to prevent microbes from gaining access to
traumatic surgically created wounds
Antiseptic and disinfectant
. Both refer to substances that can prevent the
multiplication of organisms capable of causing infection. The difference is
that antiseptics are applied to living tissue, whereas disinfectants are
designed for use on inanimate objects.
Sterility
is the freedom from viable forms of microorganisms. It represents
an absolute state; there are no degrees of sterility.
Sanitization is
the reduction of the number of viable microorganisms to
levels judged safe by public health standards.
Decontamination
is similar to sanitization, except it is not connected to
public health standards.
The bacteria that cause infection
are
most commonly part of the indigenous
bacteria that normally live on or in the host.
(e.g bacteria causing dontogenic infections)
Ex . normal oral flora consists of aerobic, gram-
positive cocci
Viruses that cause the most difficulty
hepatitis B and C viruses, and HIV
Hepatitis virus is exceptionally resistant to desiccation
HIV loses its infectivity once desiccated. In addition,
Extremely few people carrying the HIV, secrete the virus in
their saliva.
All patients infected with HIV who have
CD4+
T-lymphocyte counts of less than 200/uL
The only mycobacterial
organism of significance to most dentists is
Mycobacterium tuberculosis. Tuberculosis is transmitted
primarily through exhaled aerosols
Techniques of Instrument Sterilization
- Physical
• Heat
• Mechanical dislodgment
• Radiation
• Ethylene oxide gas - Chemical
• Antiseptics
• Disinfectant
Dry Heat:
By using
a thermostatically controlled oven and a timer. Dry heat is most commonly used to sterilize
glassware and bulky items that can withstand heat
Dry Heat , advantages and disadvantages
The advantages of dry heat are the relative ease of
use and the unlikelihood of damaging heat-resistant
instruments. Low cost.
The disadvantages are the
time necessary and the potential damage to heat-
sensitive equipment.
Moist heat is more efficient than dry heat for sterilization because
it is effective at much lower temperatures and requires less time.
The container usually used for providing steam under pressure is known as
An autoclave
Moist Heat advantages and disadvantages
The advantages of sterilization with moist heat are its effectiveness,
speed, and the relative availability
Disadvantages include the tendency of moist heat to dull and
rust instruments, the cost and complexity of autoclaves.
Guide line for dry-heat and steam sterilisation
116c = 60 min
118c = 36 min
121c = 24 min
125c = 16 min
132c = 4 min
138c = 1.5 min
In gaseous sterilisation…
Ethylene oxide is the most commonly
used. At 50
Gaseous sterilisation advantages and disadvantages
The advantages of ethylene oxide for
sterilization are its effectiveness for
sterilizing porous materials, large
equipment, and materials sensitive
to heat or moisture
The disadvantages are the need for
special equipment and the length of
sterilization, ethylene oxide is toxic
and flamable.
Chemical disinfectants,
Substances acceptable for disinfecting
dental instruments for surgery include
include glutaraldehyde, iodophors, chlorine
compounds, and formaldehyde; glutaraldehyde ( for 10 min or more , brand names cidex and omnicide) containing compounds are the most commonly used.
absolutely sterile surgical field is
impossible
Surgical field maintenance ex
by use of
a flat platform, and two layers of
sterile towels or waterproof
paper
In Hand and arm preparation , The three antiseptics most commonly used in dentistry are :
(1) iodophors,
(2) chlorhexidine, and (3) hexachlorophene.
The two basic types of personnel asepsis to be discussed are
(a) the clean
technique and (b) the sterile technique.
Clean technique is used for
office-based
surgery that does not specifically require a sterile technique ( no skin
incisions).
The sterile technique is used for
is used for office-based surgery
when skin incisions are made or when surgery is performed in an
operating room.
The theory on which the universal precautions
concept is based
is that protection of self, staff,
and patients from contamination by using barrier
techniques when treating all patients as if they all
had a communicable disease ensures
barrier technique
Techniques that prevent the transfer of pathogens from
one person to another are referred
most commonly used barriers are:
Mask
Gowns
Caps and shoe covering
Gloves
