This document discusses sterilization practices in orthodontics. It begins with an introduction on the history of infectious disease and prevention. Key terms like asepsis, infection, and sterilization are defined. The document then discusses the history of understanding disease transmission and important figures like Fracastorius and Leeuwenhoek. It describes the categorization of instruments as critical, semi-critical, or non-critical and outlines sterilization and disinfection practices. Personal protective equipment like gloves, masks, and protective eyewear are discussed. The document concludes with recommendations for surface disinfection and limiting contaminated aerosols and splatter.
2. INTRODUCTION
Infectious diseases have scourged the
world throughout history.
Even today, infectious diseases have
been discovered at a rate of one disease
per year over the past 22 years.
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3. As the old saying goes "Prevention is
better 'than cure".
Such universal precautions must be both
comprehensive, to prevent infection
transmission in all clinical situations,
and realistic, to allow convenient
provision of dental treatment.
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4. HISTORY
The belief that disease was a result of
human wrong doings was common and did
not change until the causes of disease and
disease transmission were investigated.
Girolamo Fracastorius - Existence of tiny
living particles that cause contagious
disease being spread by direct contact
with humans and animals and by indirect
contact with objects.
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5. Antony Van Leeuwenhoek who is considered
"Father of Microbiology“ studied the debris
surrounding teeth and was the first to observe
bacteria using a crudely built microscope.
Sammelweis in Vienna and Holmer in U.S.A.
first recognised the importance of hand washing
in preventing the spread of disease agents.
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6. TERMINOLOGIES
ASEPSIS
The absence of infection or infectious materials or
agents. (Miller)
INFECTION
Infection is the multiplication and survival of
microorganisms on or in the body. An infection does
not always indicate disease, but disease seldom results
Without infection. (Miller).
INFECTION CONTROL
Infection Control is the prevention of multiplication
and survival of microorganisms on or in the body of
living and non living objects.
It is the sum total of all the measures taken to prevent
subsequent infection
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7. STERLIZATION
It is defined as the process by which an article,
surface, or medium is freed of all
microorganisms either in vegetative or spore
state. (Panikar)
Denoting the use of physical or chemical agents
to eliminate all viable microbes, including all
bacteria, viruses and spores. (Jerry R. Mc Ghee)
Sterilization is the process designed to kill
bacterial spores, therefore its intended use is to
kill all microorganisms. (D.C.N.A. 1991)
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8. DISINFECTION:
Disinfection means the destruction of all
pathogenic organisms or organisms capable of
giving rise to infection. (Paniker)
Disinfection is a less lethal process intended to
kill disease producing microorganisms but not
bacterial spores (D. C. N. A - 199 1).
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11. MICROORGANISM
Hepatitis B (HBV)
Hepatitis C (HCV)
Hepatitis D (HDV)
Herpes simplex type I
DISEASE
Hepatitis B
Non -a non-B, hepatitis
Delta hepatitis
Oral herpes, Herpetic
Whitlow ,Herpatic keratitis
Herpes simplex type II Genital herpes
HIV
AIDS & ARC
Neisseria gonorrhoeae
Gonorrhoea
Treponema pallidum
Syphilis
Pseudomonas aeruginosa Wound infections, abscesses
Wound infection, abscesses
Staphylococcus aures
Clostridium tetaniwww.indiandentalacademy.com
Tetanus
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12. Micro organisms transmitted by
inhalation
Micro organism
Disease
Varicella virus
cytomegalovirus
Measles (rubeola)
Influenza virus
Rubella virus
Chicken pox
Infections in infants
Measles and mumps
Myobacterium tuberculosis
Influenza and common cold
German measles
Tuberculosis
Sterptococcus pyogens
Oral abscesses, rheumatic
fever & endocarditis
Candida albicans
candidosis
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13. Transmission of Infection
Infection transmission during dental
procedures is dependent on four factors:
Source of infection
Means of transmission
Route of transmission
Susceptible host
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15. How dental staff acquires
infections
Injuries caused by contaminated
instruments
Injuries caused by contaminated
instruments may create a portal of entry for
pathogenic micro-organisms. If the number
of micro-organisms introduced by this
route exceeds the infective dose, infection
may result.
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16. Risk of infection following needle
stick injury
The estimated blood on a needle stick is
about 1.4µL and the amount required to
cause an hepatitis or HIV infection is about
0.1µL and the incidence of infection is
about 20 -25%after needle stick injury.
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17. Existing lesions on the operator's
hands
The incidence of HBV infection among the
dental profession is about five times higher
than in the general population.
Members of the orthodontist’s team who
operate ungloved are at risk.
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18. Dental aerosol
Aerosol is defined as small droplets,
usually 5 µ or less in diameter, which can
remain suspended in air for some time.
Mycobacterium tuberculosis has been
detected in dental aerosols and there is an
increased incidence of tuberculosis in
dental professionals.
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19. Splashes of contaminated sharp
material
When operating the turbine hand piece,
particles over 0. 1 mm in diameter are
dispersed up to 6 meters at speeds of 50-60
km.
It has been suggested that hepatitis B and
herpes simplex type I can be transmitted
by these means
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20. How does the patient acquire
infection
Lesion on the operators ungloved
hands
Contaminated gloves or hands
Contaminated instruments and other
dental equipment.
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21. Manifestation in dental health care
workers
HERPETIC WHITLOW (due to ungloved hands)
HERPETIC KERATITIS(caused by contaminated
aerosols)
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22. CATEGORIZATION OF
INSTRUMENTS
Critical instruments
If an instrument will
be used to penetrate
tissue or to touch
bone it must be
sterilised.
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23. Semi-critical instruments
Semi-critical
instruments: mirror,
probe, and tweezers.
If an instrument will
touch mucous
membranes, but will
not be used to
penetrate tissue or to
touch bone,it should
be sterilised.
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24. Non-critical instruments
These are defined as
equipment and
surfaces which
contact only intact
skin, such as mixing
slabs and spatulas.
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25. Hand Washing
To destroy pathogenic micro-organisms which
collect on the hands
To prevent blood which contains pathogenic
micro-organisms
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26. Mechanical removal of debris and
of transient micro-organisms
Rubbing removes micro-organisms from
the skin.
Lathering holds them suspended away
from the skin's surface.
Rinsing washes them off the hands.
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27. Disinfection
The disinfectant action of hand washing
will destroy in situ micro-organisms on the
surface of the hands.
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28. Hand scrubs and hand washes
Properties
Act fast
Not irritate the skin after repeated
use
Have a broad range of bactericidal
and residual activity.
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29. Antiseptics used in hand washing
Chlorhexidine
This is 2-4% chlorhexidine gluconate with 4%
isopropyl alcohol in a detergent solution with a
pH of 5.0 to 6.5.
More effective than povidone iodine
POVIDONE IODINE
These products contain 7.5% to 10% povidone
iodine providing 0.75% to 1.00% available
iodine.
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30. Phenolic compounds
Hexachlorophene
Can be absorbed into the blood stream
through intact skin, although it is more
readily absorbed through abraded skin. It
may be toxic if the blood concentration
rises with repeated exposure.
Parachlorometexylenol (PCMX) is
bactericidal and fungicidal at 2%
concentration. It is not toxic.
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31. ALCOHOLS
Ethyl alcohol and isopropyl alcohol are widely
used as topical skin antiseptics, and have a potent
bactericidal effect, especially at 70%
concentration.
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34. Elbow taps should be used
and clean tissue should be
used for wiping
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35. Personal hygiene
Facial hair should be covered with a face
mask
Hair should be short or kept away from the
face.
Jewellery should not be worn on the hands
or arms during clinical sessions.
Nails must be kept clean and short.
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36. Personal Protection
Barriers considered essential when
performing all dental procedures are:
Gloves
Masks
Protective eyewear
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37. Gloves
The main types of gloves used in dentistry
are:
Latex gloves: non-sterile and sterile
Vinyl gloves: non-sterile and sterile
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38. Latex gloves
To protect patients from becoming infected
with micro organisms on the operator's
hands.
To protect the operator and staff from
microorganisms present in the patient's
blood and saliva
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40. Single use versus re-use
Repeated use of one pair of gloves with
disinfection between patients is not advisable for
the following reasons
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41. Double gloving
Double gloving
reduces the risk of
puncture.
The enhanced safety
has to be balanced
against the discomfort
or reduced dexterity.
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45. Orthodontist's gloves
The risk of glove puncture is high for
orthodontists, who repeatedly handle wire
bands and ligatures.
Orthodontist can use puncture resistant
gloves which are thicker at the palm, a
high stress area for ligature placement and
thinner material at the finger tips.
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46. Masks
Aerosols and splatter
Aerosols are generated by turbine handpieces,
air/water syringes, and ultrasonic scalers.
Droplets of blood are also splattered over the
face during dental procedures, and these may
contact existing skin lesions or skin damaged by
sharp, flying debris.
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47. Properties of an ideal mouth
mask
It has a bacterial filtration efficiency of
95% or more
It does not contact nostrils or lips
It has both high filtration of small particles
Close fit around the entire periphery
It does not cause fogging of the eye glasses
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48. The nose piece of the fluid shield mask
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49. Eye Protection
Causes of eye damage
Sharp particles projected at speed from the
mouth when using the turbine hand piece,
ultrasonic scaler, and air/water syringe
may cause eye injury
Blood/saliva droplets may enter the
operator's eyes and may transmit infection.
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50. Protective glasses with side pieces
A chin length face shield
which protects the whole face
Disposable with a www.indiandentalacademy.com
plastic face shield
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51. LIMITING CONTAMINATED
AEROSOLS AND SPLATTER
Pre treatment brushing and use of a pre
treatment mouth wash
High velocity aspiration
The use of rubber dam
Efficient air filtration and ventilation
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53. Protective clothing
To protect street clothes from contamination,
wear a uniform or cover with a gown or coat.
Contaminated clothes should be washed at 80ºC
for 10 mins using a strong detergent and bleach if
possible
Sleeves
Long-sleeved uniforms are recommended. Tuck
the bottoms of the sleeves into the gloves
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54. Tuck bottom of sleeves into the gloves
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55. Footwear
A pair of smooth, slip-on shoes should be
kept exclusively for use in the surgery.
These should be cleaned at the end of each
clinical session.
Head covers
Head covers provide an effective barrier.
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56. Covering surfaces
Surfaces can be covered with
Clear plastic wrap
Aluminium foil
Paper with impervious backing
Commercially available ,polythene sheets and
tubing
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59. Recommended surface disinfectants
PRODUCT
DILUTION
RECOMMENDE
D TIME
SODIUM
HYPOCHLORIT
E5.25%
(BLEACH)
1:10
10 mins
IODOPHORS
Biocide
Surf-a-cide
1:213
10 mins
COMBINATION
SYNTHETICS
Phenolics
Multicide
Omni II
Vitaphine
1:32
10 mins
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60. All these materials have the disadvantage
of leaving surfaces wet for 10 minutes,
which is inconvenient in a busy dental
practice.
Glutaraldehyde products that are intended
to be used as surface disinfectants contain
only 0.25% (w/v) glutaraldehyde.
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61. Disinfection of small surfaces
between patients
Preclean, using the spray-wipe technique,
with a recommended pre cleaning solution
or water and detergent.
Spray with a product containing 70%
alcohol, plus a low concentration of
synthetic phenolic. Leave this solution on
the surface for 3 minutes.
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62. Spillages
Cover the spillage with
Virkon powder or
Presept granules and
leave for 3 minutes
Remove the residue
using strong paper
towels soaked in
disinfectant (sodium
hypochlorite or
Virkon) and place these
in a disposal bag.
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63. Disposables
If an instrument or item cannot be satisfactorily
sterilized or disinfected, then choose a disposable
alternative.
If an instrument or item can be appropriately
sterilized or disinfected quickly, efficiently, and
with minimal damage, do, not use the disposable
alternative unless it is very cheap and of similar
quality.
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67. The advantages of using trays
Allows instruments to be set up in an
organised way.
Restrict gross contamination to a surface
which can be cleaned and sterilised
Provide safe, aseptic storage (pouches and
paper wraps may be penetrated by sharp
instruments).
Trays are particularly useful for sets of
larger instruments.
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68. Sterilisation Pouches
Pouches are very useful for the sterilisation and
aseptic storage of single instruments
Each pouch should be flatted by hand, to drive
out most of the air, and must contain a chemical
time/temperature indicator strip.
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72. Pre-Sterilisation Disinfection
After use, Place instruments into a disinfectant
detergent solution in a container located within
the operating zone near to the dentist.
At the end of the dental procedure, take the
container to the sterilisation area. Thoroughly
rinse the instruments with water. The solution
should be discarded daily.
A synthetic phenolic solution diluted 1:32, is
an ideal holding solution
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73. PRE STERILISATION CLEANING
Proteinaceous material protects microorganisms on the surface of instruments
from heat and other sterilisation
conditions. Pre-sterilisation cleaning may
be achieved in one of three ways:
Hand scrubbing
Ultrasonic cleaning
Dishwasher instrument cleaning.
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75. Sterilisation
Instruments must be clean and dry before
sterilisation.
There are four types of sterilisers used
routinely :
The steam autoclave.
The chemical vapour pressure steriliser.
The dry heat oven.
The glass bead/salt steriliser.
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76. THE STEAM AUTOCLAVE
A steam autoclave sterilises by the use of steam
under pressure. Non-vacuum autoclaves are used
in dental practice.
A prescribed temperature, pressure, and time are
necessary to destroy bacterial spores. The faster,
higher temperature cycles are generally favored
by dentists in general practice.
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77. Chemical vapour sterilisers
Chemical vapour sterilisers operate by heating a
deodorized alcohol, formaldehyde, and ethyl
methyl ketone solution, which can be obtained
from the manufacturer, to 132ºC at 138-276 kPa
(20-40 lb/in2) for 20 minutes in a closed
chamber.
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78. Instruments suitable for sterilisation
with chemical vapour
All dental hand instruments.
Orthodontic wires and bands.
Orthodontic pliers
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79. Dry-heat sterilisers
Convection heat has become a popular means of
sterilisation of instruments for orthodontic
offices.
Dry heat is an effective means of sterilisation,
when it is used properly. Unwrapped, moderate
loads of instruments placed in an oven can be
sterilised at 160-170ºC in I hour.
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81. GLASS BEAD STERILIZER
To have an effective sterilization one has to have
many sets of instruments where single use is
possible after sterilizing them in a hot air oven, or
one has to wait for long enough to have
effectively sterilized in between appointments.
So there is acute necessity in the orthodontic
office set up, where instruments can be sterilized
quickly and rapidly.
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83. Disinfection of impressions
The most commonly used impression
material is alginate and these impressions
are highly infected when removed from the
patients mouth
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84. Recommended Procedure for
disinfecting the alginate impression
Rinse the impression thoroughly under running
tap water, shake the impression to remove excess
water.
Dip the impression in a 1:10 solution of sodium
hypochlorite for several seconds to ensure
maximum contact of undercut with the
disinfectant.
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85. Wrap the impression in gauze soaked in
1:10 sodium hypochlorite, place in a
plastic bag and seal for 10 minutes.
Remove the impression and rinse
thoroughly under running tap water.
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86. Visible-light curing units
Some new designs of unit feature removable,
autoclavable light curing tips. However, the
handles still present a problem, since they cannot
be sterilised.
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87. Units: Should be cleaned and disinfected
with a phenolic disinfectant after use.
Plastic units should be disinfected using
an iodophor.
Glutaraldehyde disinfectants have been
found to damage the glass rods in a fiberoptic light tip, with a subsequent reduction
in light output; the use of this disinfectant
should be avoided.
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88. Monitoring sterilisation
Tests using chemical indicators
Test strips or tubes are available
for autoclaves, chemiclaves, and
dry-heat ovens
Several types of colour-change
strips or tapes indicate
temperature change only, that is,
they only show that the load has
been in a heat steriliser.
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89. Biological Monitors
Bacillus stearothermophilus
is used for chemical vapour
and steam sterilisers, and B.
subtilis is used for dry-heat
spore testing.
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90. Disposal Clinical Waste
Used disposable
scalpels, anaesthetic
cartridges, used burs,
orthodontic wire,
extracted teeth, and
other sharp objects
should be carefully
dropped into a solid
puncture-resistant
container
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92. CATEGORY OF WASTE
CONTAINER
CAT
I
Blood body fluids bandages,
microbiology,& biotechnology
waste, extremely soiled lining
Tubes ,buckets Yellow
with lids
CAT
2
Sharps
Reusable sharps such as needles
scalpels surgical instruments
Waste sharps such as broken glass
disposable needles broken blades
Stainless steel
White or
translucent
Card board
boxes
Blue
CAT
3
Disposable plastics gloves
Bgs or buckets
stain less steel
drums
Red
CAT
4
Chemical waste
Buckets with
Black
lids ,card board
cartons
CAT
5
Compostable waste
Buckets and
drums
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COLOUR
Green
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93. SUMMARY
In every health profession the guiding principle is
“DO GOOD BUT DO NO HARM” is as
HARM
applicable today as it was in the time of
Hippocrate.
Sterilization in orthodontic office is an important
exercise, due to unabated spreading of HIV virus,
hepatitis viruses, there is a great concern
regarding the sterility of orthodontic instruments.
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94. WHICH IS THE IDEAL
METHOD ?
The ideal method for sterilization should
be economical , less time consuming ,with
low maintenance cost , require minimum
space and infrastructure and the method
which complies by all these requirements
is a GLASS BEAD STERILIIZER
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