Sterilization in orthodontics (4)

STERILIZATION INSTERILIZATION IN
ORTHODONTICSORTHODONTICS
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INTRODUCTIONINTRODUCTION
 In every health profession the guiding principle isIn every health profession the guiding principle is
‘DO‘DO GOOD BUT DO NOT HARM’GOOD BUT DO NOT HARM’ is as applicable today as itis as applicable today as it
was in the time of HIPPOCRATES.was in the time of HIPPOCRATES.
 The most effective way of prevention isThe most effective way of prevention is STERILIZATIONSTERILIZATION
 Sterilization destroys all microorganisms but should beSterilization destroys all microorganisms but should be economialeconomial
and should be less time consuming .and should be less time consuming .
Negligence for an effective precaution leads to transmission ofNegligence for an effective precaution leads to transmission of
infectious diseases to the professional, by stander and theinfectious diseases to the professional, by stander and the
patients.patients.
•The above consideration lead us to necessity of betterThe above consideration lead us to necessity of better
infection control methods – Asepsis.. Disinfection.. Sterilizationinfection control methods – Asepsis.. Disinfection.. Sterilizationwww.indiandentalacademy.comwww.indiandentalacademy.com

DEFENITION OF TERMSDEFENITION OF TERMS
 STERILIZATIONSTERILIZATION –– it is defined as a process by which anit is defined as a process by which an
article ,surface or medium is freed of all micro organisms eitherarticle ,surface or medium is freed of all micro organisms either
in the vegetative or spore statein the vegetative or spore state
- It is the process designed to kill all bacterial spores , therefore- It is the process designed to kill all bacterial spores , therefore
its intended use is to kill all microorganisms .its intended use is to kill all microorganisms .
(D.C.N.A 1991 )(D.C.N.A 1991 )
- The process of completely eliminating microbial viability- The process of completely eliminating microbial viability
((J.C.O 1993)((J.C.O 1993)
ARTICLES FREE OF LIVING ORGANISMS ARE SAID TO BE STERILEARTICLES FREE OF LIVING ORGANISMS ARE SAID TO BE STERILE
 DISINFECTIONDISINFECTION –– Means the destruction of all pathogenicMeans the destruction of all pathogenic
organisms or organisms capable of giving rise to infectionsorganisms or organisms capable of giving rise to infections

 Its a lethal process intented to kill disease producingIts a lethal process intented to kill disease producing
micro organisms but not bacterial spores (D.C.N.A.micro organisms but not bacterial spores (D.C.N.A.
1991)1991)
 ASEPSIS –ASEPSIS – The absence of infection , infectious
material 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 with out infections (MILLER)
 Cross infectionCross infection ––it’s the passage of micro organismsit’s the passage of micro organisms
from one person to another by direct or indirectfrom one person to another by direct or indirect
transmissiontransmission

COMMON DISEASES TRANSMITTED INCOMMON DISEASES TRANSMITTED IN
ORTHODONTIC OFFICEORTHODONTIC OFFICE

MODE OF TRANSMISSIONMODE OF TRANSMISSION
 From patient to practitionerFrom patient to practitioner
 From practitioner to patientFrom practitioner to patient
 From one patient to another.(cross infection)From one patient to another.(cross infection)

Route of transmissionRoute of transmission
1)1) INOCULATIONINOCULATION ::
Accidental self injuryAccidental self injury
with a contaminatedwith a contaminated
needle , sharpneedle , sharp
instruments.instruments.
 MicroorganismsMicroorganisms
transmitted includestransmitted includes
1.1. HBVHBV
2.2. HCVHCV
3.3. HDVHDV
4.4. HSV 1 N 2HSV 1 N 2
5.5. HIVHIV
6.6. NeisseriaNeisseria
7.7. GonorroheaGonorrohea
8.8. TreponemaTreponema
9.9. Clostridium tetaniClostridium tetani

2) INHALATION2) INHALATION ::

Inhalation ofInhalation of
micro organismsmicro organisms
aerosolized fromaerosolized from
patients saliva or bloodpatients saliva or blood
occurs while using highoccurs while using high
speed or ultrasonicspeed or ultrasonic
equipment.equipment.
1.1. Varicella zosterVaricella zoster
2.2. CMVCMV
3.3. RubeolaRubeola
4.4. RubellaRubella
5.5. MycobacteriumMycobacterium
TuberculosisTuberculosis
6.6. Candida AlbicansCandida Albicans

WHAT’S INFECTION CONTROL ?WHAT’S INFECTION CONTROL ?
 THIS IS THE LIMITING OF SPREAD OFTHIS IS THE LIMITING OF SPREAD OF
INFECTIONS VIA DIFFERENTINFECTIONS VIA DIFFERENT
CHANNELS IN A SPECIFIC OR GENERALCHANNELS IN A SPECIFIC OR GENERAL
ENVIRONMENT.ENVIRONMENT.
 Procedures can be grouped under 2Procedures can be grouped under 2
categories..categories..
1.1. Those which interfere with the spread ofThose which interfere with the spread of
infectious agents by reducing contamination .infectious agents by reducing contamination .
2.2. Those which remove or kill the disease agentsThose which remove or kill the disease agents
after contamination has occurred .after contamination has occurred .

AREAS OF INFECTION CONTROLAREAS OF INFECTION CONTROL
Employees are divided into three categoriesEmployees are divided into three categories
according to their degree of exposure to infectiousaccording to their degree of exposure to infectious
materials.materials.
Category ICategory I includes employees such as dentists,includes employees such as dentists,
dental hygienists, chairside assistants, anddental hygienists, chairside assistants, and
laboratory technicians who are regularly exposed tolaboratory technicians who are regularly exposed to
blood, body fluids, or body tissues.blood, body fluids, or body tissues.
Category IICategory II includes business staff and cleaningincludes business staff and cleaning
people, whose regular tasks involve no exposure topeople, whose regular tasks involve no exposure to
bloody body fluids, or tissues, but whosebloody body fluids, or tissues, but whose
employment may require exposure, planned oremployment may require exposure, planned or
unplanned.unplanned.
Category IIICategory III includes any other employeeincludes any other employee
1.1. Orthodontist n staffOrthodontist n staff
JCO Volume 1990 Jul(417 - 426)JCO Volume 1990 Jul(417 - 426)

2)2) CONTAMINATIONCONTAMINATION VEHICLESVEHICLES ,,PAYNE AJO 1986PAYNE AJO 1986
Orthodontist must decide for himself which instrument toOrthodontist must decide for himself which instrument to
be sterilizedbe sterilized..
InstrumentsInstruments
can be grouped in to 3 categoriescan be grouped in to 3 categories....
1.1. Critical:Critical: Instruments that penetrate the mucosa n has toInstruments that penetrate the mucosa n has to
be sterilized. Eg.. Bands, Band removers, Ligaturebe sterilized. Eg.. Bands, Band removers, Ligature
directors, Band forming pliers etc…directors, Band forming pliers etc…
2.2. Semi critical:Semi critical: Instruments that touches the mucosa soInstruments that touches the mucosa so
needs to be sterilized. Eg.Mirror, Retractor etc..needs to be sterilized. Eg.Mirror, Retractor etc..
3.3. Least critical:Least critical: Eg. Ligature tier ,distal end cutter , TyingEg. Ligature tier ,distal end cutter , Tyingwww.indiandentalacademy.comwww.indiandentalacademy.com

33.. OPERATOR SITEOPERATOR SITE
 Dental chair , Light handles ,Spittoon , ThreeDental chair , Light handles ,Spittoon , Three
way syringes etc.. has to be frequently wipedway syringes etc.. has to be frequently wiped
with 70% isopropyl alcoholwith 70% isopropyl alcohol

INFECTON CONTROL MEASURESINFECTON CONTROL MEASURES
1.1. PATIENT SCREENINGPATIENT SCREENING
2.2. IMMUNOLOGICAL PROTECTION.IMMUNOLOGICAL PROTECTION.
3.3. BARRIER PROTECTIONBARRIER PROTECTION
4. INSTRUMENT STERILIZATION
5. DISPENSING MATREIALS WITH
MINIMUM CONTAMINATION
6. DISPOSAL OF WASTE.

1.1. Patient screeningPatient screening ::
Every patient has to be consideredEvery patient has to be considered
potentially infectious. So a properpotentially infectious. So a proper case historycase history andand
an appropriatean appropriate evaluation of the questionnaireevaluation of the questionnaire helpshelps
the clinician to arrive in to a proper diagnosis ofthe clinician to arrive in to a proper diagnosis of
many oral and systemic diseasesmany oral and systemic diseases..
2.2. IMMUNOLOGICAL PROTECTION:IMMUNOLOGICAL PROTECTION:
The occupational risk of microbial infections can beThe occupational risk of microbial infections can be
minimized by stimulating artificial active immunity.minimized by stimulating artificial active immunity.
The orthodontists and staff should undergoThe orthodontists and staff should undergo
vaccinationvaccination

3.3. BARRIER CONTROL:BARRIER CONTROL:
This includes the physical barriersThis includes the physical barriers
used during the normal treatment procedures against theused during the normal treatment procedures against the
potential pathogens. This includes…potential pathogens. This includes…
1.1. GlovesGloves
2.2. Mouth maskMouth mask
3.3. Protective clothingProtective clothing
4.4. Protective eye wearProtective eye wear
5.5. Surface coveringsSurface coverings
6.6. Use of disposable materialsUse of disposable materials
7.7. Proper hand washingProper hand washing

TYPES OF GLOVESTYPES OF GLOVES
1.1. Vinyl or latex - sterile, single use - surgicalVinyl or latex - sterile, single use - surgical
procedure.procedure.
2.2. Vinyl or latex - non sterile, single use - examinationVinyl or latex - non sterile, single use - examination
3.3. Rubber / plastic material - non sterile, multiple use - overRubber / plastic material - non sterile, multiple use - over
gloving.gloving.
4.4. Polyethylene - non-sterile, multiple use -over gloving.Polyethylene - non-sterile, multiple use -over gloving.
5.5. Nylon glove – non sterile ,multiple use –using beneathNylon glove – non sterile ,multiple use –using beneath
gloves.gloves.

PRECAUTIONS WHILE USING GLOVESPRECAUTIONS WHILE USING GLOVES
 Wear gloves for all dental procedureWear gloves for all dental procedure ..

Discard gloves whenever they have beenDiscard gloves whenever they have been
contaminated.contaminated.
 Do not leave the clinic or walk around wearingDo not leave the clinic or walk around wearing
gloves.gloves.
 Wash hands after removing gloves.Wash hands after removing gloves.
 The risk of glove puncture is high for orthodontistsThe risk of glove puncture is high for orthodontists
as they handle wires brackets and bands. So the useas they handle wires brackets and bands. So the use
of puncture resistant gloves is recommended whichof puncture resistant gloves is recommended which
are thicker at the palms (high stress area) and thinnerare thicker at the palms (high stress area) and thinner
at finger tips .at finger tips .

REPROCESSING OF GLOVESREPROCESSING OF GLOVES
 Rinse your gloved hands thoroughly in a hypochloriteRinse your gloved hands thoroughly in a hypochlorite
solution.solution.
 Then wash in clear water to remove the disinfectant.Then wash in clear water to remove the disinfectant.
 Wash with soap and water and rinse thoroughly.Wash with soap and water and rinse thoroughly.
 Remove the gloves and hang them up by the cuffs to dry .Remove the gloves and hang them up by the cuffs to dry .
 Dust glove powder on the inside of the gloves .
 Autoclave the gloves

2.MOUTH MASKS2.MOUTH MASKS
 Surgical masks / chin length plastic faceSurgical masks / chin length plastic face
shields must be worn to protect the face.shields must be worn to protect the face.
 Should have at least 95% filtration efficiencyShould have at least 95% filtration efficiency
for particles 3-5 micrometer in diameter.for particles 3-5 micrometer in diameter.
 Should be changed for each patient since itsShould be changed for each patient since its
efficiency decreases.Moreover it trapsefficiency decreases.Moreover it traps
moisture during dental procedures.moisture during dental procedures.

Use of face mask n eye wearUse of face mask n eye wear

3. PROTECTIVE EYE WEAR3. PROTECTIVE EYE WEAR
 The eyes of a dental professional are particularlyThe eyes of a dental professional are particularly
susceptible to physical & microbial injury bysusceptible to physical & microbial injury by
virtue of their limited vascularity and diminishedvirtue of their limited vascularity and diminished
immune capacities.immune capacities.
 Eyes must be protected during operativeEyes must be protected during operative
procedures by spectacles.procedures by spectacles.

4.HAND WASHING4.HAND WASHING
 First scrub hands with warm water.
 Get soap under the nails and clean with
brush.
 Rinse hands with cold water.
 Wipe hands with paper towel or dry with
warm air.

AGENTS FOR HAND WASHINGAGENTS FOR HAND WASHING

5. PROTECTIVE CLOTHING5. PROTECTIVE CLOTHING
 OSHA emphasizes the need of wearing aOSHA emphasizes the need of wearing a Long-
sleeved, jewel-neck clinic jackets in the laboratory
and operatory
 These procedures will inevitably sow microThese procedures will inevitably sow micro
organisms in to the fabric of the apron.organisms in to the fabric of the apron. These jackets
should be replaced daily, or when visibly soiled, and
worn only in the office
 The jackets must be laundered by a single source
to simplify tracing in case of an exposure incident.
JCO 1997 AUG

6. SURFACE COVERINGS6. SURFACE COVERINGS
 Materials used should be impervious to
moisture (impervious- backed paper,
aluminium foil /plastic covers ).
 On surfaces difficult to clean.
 To be changed between patients.

 DentalDental
chairchair
coveredcovered
withwith
plasticplastic
wrap fromwrap from
arms uparms up
for aerosolfor aerosol

7. SPRAY - WIPE SPRAY TECH.7. SPRAY - WIPE SPRAY TECH.
 Spray the surface.
 Wipe in systematic pattern contacting each
 surface at least twice.
 Spray again.
 Allow solution to dry and then wipe in 10 minutes for
proper disinfection.

The recently introduced Vitawipes are disposable
disinfectant cloths containing polyhydrochloride
(3.2 percent), alkyl dimethyl, benzyl ammonium
chloride (7.1 percent), and inert ingredients
(89.7 percent). A cloth is dampened with water
and used to wipe contaminated surfaces. The
cloth is disposed of after an indicator strip
changes color or after wiping a surface
contaminated with hepatitis B virus. The wipes
are easy to use and show minimal reaction with
skin.

8. HOW TO STERILIZE THE PENCIL8. HOW TO STERILIZE THE PENCIL
TIPSTIPS

JCO Volume 1998 May(307 - 310JCO Volume 1998 May(307 - 310))
 Conventional orthodontic marking pencils cannot beConventional orthodontic marking pencils cannot be
autoclaved. Currently gas sterilization is effective inautoclaved. Currently gas sterilization is effective in
killing bacteria, but is also costly and difficult, makingkilling bacteria, but is also costly and difficult, making
it impractical for orthodontic office.it impractical for orthodontic office.
 The only sure way to avoid potential cross-The only sure way to avoid potential cross-
contamination is to use the inexpensive disposablecontamination is to use the inexpensive disposable
markers available from orthodontic supply companies.markers available from orthodontic supply companies.
 At least break off the tip of the lead before using it inAt least break off the tip of the lead before using it in
next patientnext patient
Fernando Ascencio

DISINFECTION OF INSTRUMENTSDISINFECTION OF INSTRUMENTS
 Hand piece
 3 way syringe tips
 Aspirators

HAND PIECESHAND PIECES
 Most are autoclavable.
 Depends on manufacturers guidelines.
 Prior cleaning and lubrication is mandatory.
 Hand piece is placed in autoclavable pouch
with TST strips (time , steam, temperature).

•Hand piece stored in a plastic wrapHand piece stored in a plastic wrap
after disinfectionafter disinfection

Three way syringe tips / high velocity evacuationThree way syringe tips / high velocity evacuation
tips / aspiratorstips / aspirators
 3 –way syringe should be treated in the same manner as3 –way syringe should be treated in the same manner as
hand piece.hand piece.
 HVE tips –metal tips are autoclavable. Plastic tips mustHVE tips –metal tips are autoclavable. Plastic tips must
be disposed off after single use.be disposed off after single use.
 Aspirators –disinfectant flushes for the aspirators shouldAspirators –disinfectant flushes for the aspirators should
be done after each patient.be done after each patient.

Disinfection of impressionDisinfection of impression
Disinfection ofDisinfection of ALGINATEALGINATE impressions :-impressions :-
 iodophores / glutaraldehyde – 15 min.iodophores / glutaraldehyde – 15 min.
 LYSOL spray – 10 min.LYSOL spray – 10 min.
 Placed in re-closable sandwich bags

 BursBurs
- ethylene oxide 4-12 hours
- autoclave.
- glass bead sterilization
 Carbon steel instrumentsCarbon steel instruments::
- chemical vapour---20 min at 270 °f
- ethylene oxide ----4-12hours
- dry heat oven---60-120 min at 320°f
 Tungsten carbide instruments :
- chemical vapour---20 min at 270 °f
- dry heat oven---60-120 min at 320°f

Method of sterilizationMethod of sterilization
 Moist heat (autoclaving)Moist heat (autoclaving)
 Dry heat (hot air oven)Dry heat (hot air oven)
 Chemicals (chemiclaving)Chemicals (chemiclaving)
JCO Volume 1994 Nov

Moist heat
 Moist heat denatures &
coagulates the protein of
microbes
 Better than dry heat
because of its higher
efficiency of
penetration.
 Due to latent heat of
vaporization present in
moist heat.
Steam autoclave

TYPES OF AUTOCLAVESTYPES OF AUTOCLAVES
1.1. POROUS LOAD AUTOCLAVESPOROUS LOAD AUTOCLAVES ::
 Auto cycled high pressure vacuum models .Auto cycled high pressure vacuum models .
 Air is evacuated from the metal chamber byAir is evacuated from the metal chamber by
vacuum suction.vacuum suction.
 12112100
C , AT 20 lb pressure for 30 min.C , AT 20 lb pressure for 30 min.
 Towels ,suture materials, cotton rolls, rubberTowels ,suture materials, cotton rolls, rubber
gloves ,root canal instruments.gloves ,root canal instruments.

2. SMALL BENCH AUOMATIC AUTOCLAVE
 Work on the principle of downwardWork on the principle of downward
displacement of air as a consequence ofdisplacement of air as a consequence of
steam entering at the top of the chamber.steam entering at the top of the chamber.
 Temp of 136Temp of 136oo
c ,at 32 lb pressure for 5 minc ,at 32 lb pressure for 5 min

STERILIZATION CYCLESTERILIZATION CYCLE
Unwrapped instrumentsUnwrapped instruments
134134oo
cc
3 min3 min
30 psi30 psi
Wrapped instrumentsWrapped instruments
12112100
cc
15-20 min15-20 min
15 psi15 psi

SATTIM CASSETE AUTOCLAVESATTIM CASSETE AUTOCLAVE
 Designed for rapid sterilization .Designed for rapid sterilization .
 Instruments sterilized in closed cassettes .Instruments sterilized in closed cassettes .
 A 6 minute cycle for unwrapped instruments andA 6 minute cycle for unwrapped instruments and
12 min cycle for wrapped instruments .12 min cycle for wrapped instruments .

DRY HEAT STERILIZATIONDRY HEAT STERILIZATION
 Higher temperaturesHigher temperatures
,longer periods &longer,longer periods &longer
heating up time requiredheating up time required
for sterilization (45 min tofor sterilization (45 min to
reach 160reach 160oo
c).c).
 Less effective than moistLess effective than moist
heat.heat.
 Should have a time clock onShould have a time clock on
the door ,so items cannot bethe door ,so items cannot be
added or removed during theadded or removed during the
cycle & a fan to distributecycle & a fan to distribute
the heat evenlythe heat evenly

GLASS BEAD STERILIZATIONGLASS BEAD STERILIZATION
 Heating glass beads in a chamber intoHeating glass beads in a chamber into
which instrument is inserted for 10-30 sec.which instrument is inserted for 10-30 sec.
 21021000
c –230c –230 00
c .c .
 Suitable for very small instruments likeSuitable for very small instruments like
R.C.T instruments ,burs ,R.C.T instruments ,burs , PLIERSPLIERS etc.etc.

CHEMICAL STERILIZATIONCHEMICAL STERILIZATION
 Combination of formaldehyde , alcohol , acetone ,Combination of formaldehyde , alcohol , acetone ,
ketone & steam at 20 psi serves as an effectiveketone & steam at 20 psi serves as an effective
sterilizing agent.sterilizing agent.
 Biocidal action of formaldehyde depends on itsBiocidal action of formaldehyde depends on its
alkylation of microbial nucleic acids, which controlalkylation of microbial nucleic acids, which control
protein synthesis.protein synthesis.
 Takes longer time than an autoclave (30 min) forTakes longer time than an autoclave (30 min) forwww.indiandentalacademy.comwww.indiandentalacademy.com

COLD STERILIZATION
 Process of disinfecting instruments / equipmentProcess of disinfecting instruments / equipment
by using a liquid chemical germicide is calledby using a liquid chemical germicide is called
Cold sterilization.Cold sterilization.
 Used for heat sensitive instruments.Used for heat sensitive instruments.
 Aseptic rinsing with sterile water and dryingAseptic rinsing with sterile water and drying
should follow this disinfection process.should follow this disinfection process.

HOW TO MONITOR STERILIZATIONHOW TO MONITOR STERILIZATION
??
1.1. Physical monitoring.Physical monitoring.
2.2. Chemical monitoring.Chemical monitoring.
3.3. Biological monitoring.Biological monitoring.
3 Forms3 Forms

PHYSICAL MONITORINGPHYSICAL MONITORING
 Refers to periodical observation ofRefers to periodical observation of displaysdisplays
or gauges on the sterilizeror gauges on the sterilizer during a cycle toduring a cycle to
ensure the sterilization process.ensure the sterilization process.

CHEMICAL MONITORINGCHEMICAL MONITORING
1.1. Process indicatorsProcess indicators :- consist of color changing:- consist of color changing
material (liquid /paper) which changes color uponmaterial (liquid /paper) which changes color upon
exposure to appropriate sterilization cycle.exposure to appropriate sterilization cycle.
22.. TST strips (TIME ,STEAM,TEMPERATURE)TST strips (TIME ,STEAM,TEMPERATURE) changechange
color when all parameters have been adequatelycolor when all parameters have been adequately
achieved in the sterilization cycle.achieved in the sterilization cycle.
Two types are availableTwo types are available

BIOLOGICA MONITORINGBIOLOGICA MONITORING
 Indicator used are heat resistant bacterialIndicator used are heat resistant bacterial
spores (spores (Bacillus stearothermophillus ,BacillusBacillus stearothermophillus ,Bacillus
subtilissubtilis ))
 If the spores are killed ,then less resistantIf the spores are killed ,then less resistant
microbes are killed more readily and sterilitymicrobes are killed more readily and sterility
is achievedis achieved

CORROSION ‘N’ HARDNESSCORROSION ‘N’ HARDNESS
 Manufacture of orthodontic instruments at 1200 – 2000Manufacture of orthodontic instruments at 1200 – 2000
F and tempered at 800 F. So pliers never damagedF and tempered at 800 F. So pliers never damaged
below 800 F. carbide inserts in pliers can be damagedbelow 800 F. carbide inserts in pliers can be damaged
only above 1500 F .only above 1500 F .
 But an increase in hardness noted after repeatedBut an increase in hardness noted after repeated
sterilization .More In case of autoclave than dry heat .sterilization .More In case of autoclave than dry heat .
.Corrosion resistance of orthodontic grade steel is
directly proportional to its carbon
content and the chromium content
( PASSIVATION EFFECT) .

TYPES OF CORROSIONTYPES OF CORROSION
-- Solution corrosionSolution corrosion
-- Debris / Interface corrosionDebris / Interface corrosion
-- Stress corrosionStress corrosion
-- Pit corrosionPit corrosion
Heat accelerates the corrosionHeat accelerates the corrosion
JCO Volume 1987JCO Volume 1987

REUSE OF ORTHODONTIC WIRESREUSE OF ORTHODONTIC WIRES
 Most of the orthodontists uses stainless steel nMost of the orthodontists uses stainless steel n
nickel titanium wires of which NITINOL wasnickel titanium wires of which NITINOL was
most commonly used.most commonly used.
 "Do we reuse nickel-titanium wires? Yes.."Do we reuse nickel-titanium wires? Yes..
 So how to sterilize it ?..So how to sterilize it ?..

1.1. Heat sterilizationHeat sterilization is the most reliable method -is the most reliable method -
(Steam autoclaving at 121(Steam autoclaving at 12100
C,15-20psi for 20 min)C,15-20psi for 20 min)
2.2. Chemical sterilizationChemical sterilization are corrosive & attackare corrosive & attack
metals immersed in them .metals immersed in them .
Alcohol ,glutaraldehyde , iodoform , chlorineAlcohol ,glutaraldehyde , iodoform , chlorine
dioxide , quaternary ammonium compoundsdioxide , quaternary ammonium compounds
are materials of choice for the sterilization ofare materials of choice for the sterilization of
arch wiresarch wires ..

Draw backs in the reuse of arch wiresDraw backs in the reuse of arch wires
 Mechanical property deteriorationMechanical property deterioration was thewas the
main concern, followed by Bmain concern, followed by Bacterial and viralacterial and viral
diseasesdiseases ....
 Wire size problems, breakage, and generalWire size problems, breakage, and general
uneasiness about placing a wire from oneuneasiness about placing a wire from one
patient's mouth into another's.patient's mouth into another's.
ADVADV :: Cost savingCost saving ..

CAUSES OF STERILIZATIONCAUSES OF STERILIZATION
FAILUREFAILURE (GEORGE 1993 JCO)(GEORGE 1993 JCO)
 CYCLE TIME TOO SHORTCYCLE TIME TOO SHORT
 TEMPERATURE TOO LOWTEMPERATURE TOO LOW
 FAILURE TO PREHEATFAILURE TO PREHEAT
 FAULTY STERILIZERFAULTY STERILIZER
 INTERRUPTING OF CYCLEINTERRUPTING OF CYCLE
 OVERLOADING OF CHAMBEROVERLOADING OF CHAMBER
 INADEQUATE STAFF TRAININGINADEQUATE STAFF TRAINING
 IMPROPER PRECLEANING, PACKAGINGIMPROPER PRECLEANING, PACKAGING
 FAILURE TO USE BIOLOGICAL INDICATOR TESTING.FAILURE TO USE BIOLOGICAL INDICATOR TESTING.

DISPENSING MATERIALS WITHDISPENSING MATERIALS WITH
MINIMUM CONTAMINATIONMINIMUM CONTAMINATION
 Disposable items such asDisposable items such as patientpatient
napkins, gauze pads, syringes, andnapkins, gauze pads, syringes, and
suction tipssuction tips are stored at the chairs.are stored at the chairs.
 ArchwiresArchwires are stored and deliveredare stored and delivered
inin Ormco Kleen Paks .Ormco Kleen Paks .
 Elastomeric ligaturesElastomeric ligatures are dispensed from TP Carouselare dispensed from TP Carousel
ligature dispensers, which dispense individual modules,ligature dispensers, which dispense individual modules,
or from strips of 10 units each, which are stored inor from strips of 10 units each, which are stored in
plastic boxes.plastic boxes.
 Spools of Alastik chain and nickel titanium wireSpools of Alastik chain and nickel titanium wire areare
kept on Unitek chain dispensers to minimize handlingkept on Unitek chain dispensers to minimize handling
during cutting.during cutting.
Takla JCO Volume 1997 AugJCO Volume 1997 Aug

 Schneeweiss in JCO 1993 described a method of cutting
elastomeric modules into smaller sections and covering them
with clear tubing, which could then be cold sterilized.
 During archwire placement, the operator contacts only the
outside tubing while removing ligatures
 More recently, dispensers have been introduced onto the market,
but the effectiveness of such dispensers in controlling cross
-infection has yet to be fully evaluatedMore recently, dispensers
have been introduced onto the market, but the effectiveness of
such dispensers in controlling cross -infection has yet to be fully
evaluated.

WASTE DISPOSALWASTE DISPOSAL
 Its should be disposed in tamper proof
containers/ boxes.
 Its should be labeled as BIOHAZARD.
 Should be in tune with the existing laws of the
area.
 Sharp material should be stored in hard walled
leak proof containers ,red in color.

Color coding for waste disposal
 Yellow --- waste for incineration .
 Yellow with --- waste for land fill .
black stripes
 Light blue--- for autoclaving before disposal
 Red ---human anatomical wastes.
 Black ---normal household wastes.

CONCLUSIONCONCLUSION
 Here ,the
orthodontist can
minimize and even
prevent the
possibility of cross
Infection .This may
be the best
protection against
the transmission of
hepatitis and other
diseases and
perhaps , the filing
of a malpractice suit
.
 Effective infection control
must be a routine
component of professional
activity .The use of
universal precautions in the
management of all patients

 INACTIVATION OF MICROORGANISMS
 Hepatitis virus→ Kobayashi and associates (1984),
using direct chimpanzee inoculation as an assay
method, found that 0.1% aqueous glutaraldehyde at
24° C for 5 minutes, 1% aqueous glutaraldehyde at
24° C for 1 minute, 80% ethanol at 11° C for 2
minutes, and heat at 98° C for 2 minutes are all able
to inactivate hepatitis B virus in human plasma.

 AIDS virus→ AIDS virus is inactivated after
treatment with 50% ethyl alcohol, 35% isopropyl
alcohol, 0.1% household bleach, Lysol, and 0.3%
H2O2 at room temperature (21° to 25° C) for 2 to 10
minutes. Heating at 56° C for 30 minutes inactivates
the AIDS virus, and one investigator found the virus
titer level dropped to undetectable levels after 10
minutes of heating at 56° C in the presence of serum.
 HTLV III/LAV has unusual stability at room
temperature. Infective viral particles have survived
for more than a week at 20° to 22° C in either dry
form or liquid medium

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