INFECTION CONTROL and STERLIZATION in DENTISTRY .ppt

How to do infection control in dentistry.

1. INFECTION CONTROL INFECTION CONTROL
IN DENTISTRY IN DENTISTRY

2. Why is infection control Why is infection control
important in dentistry? important in dentistry?

Both patient and dental personnels can Both patient and dental personnels can
be exposed to pathogens be exposed to pathogens

Contact with blood and contaminated Contact with blood and contaminated
equipments occurs equipments occurs

Proper procedures can prevent the Proper procedures can prevent the
transmission of infection to the patient transmission of infection to the patient

3. Rationale for infection controlRationale for infection control

Infection control program is designed to Infection control program is designed to
prevent or atleast reduce the spread of prevent or atleast reduce the spread of
diseased agents from the following:-diseased agents from the following:-
Patient to dental team Patient to dental team
Dental team to patientDental team to patient
Patient to patientPatient to patient
Dental office to communityDental office to community
Community to patientCommunity to patient

4. Infection can spread form Patient Infection can spread form Patient
to dental team viato dental team via

Direct contactDirect contact

Droplet infectionDroplet infection

Indirect contactIndirect contact

5. Infection from Dental team to Infection from Dental team to
patientpatient

Is Is rare but occurs if the members of rare but occurs if the members of
dental team do not follow proper dental team do not follow proper
procedureprocedure like if the hands are injured like if the hands are injured
while in patients mouth while in patients mouth
microorganisms could be transferred by microorganisms could be transferred by
direct contact with the patients mouth direct contact with the patients mouth

6. Disease agents might be Disease agents might be
transferred from transferred from patient to patient to
patientpatient by by indirect contactindirect contact
through improperly prepared through improperly prepared
instruments hand pieces, instruments hand pieces,
operatory surfaces and handsoperatory surfaces and hands

7. Infection from Infection from dental office to dental office to
communitycommunity occurs occurs if the if the
microorganisms from the microorganisms from the
patients contaminate itemspatients contaminate items that that
are sent out or are transported are sent out or are transported
away from the officeaway from the office

8. Goals of infection controlGoals of infection control
includes 3 basic factorsincludes 3 basic factors
namelynamely
virulencevirulence
dose dose
resistanceresistance
Health=Health=virulence x dosevirulence x dose
resistance resistance
Thus goal of infection is to Thus goal of infection is to reduce dose of reduce dose of
microorganisms microorganisms

9. 
Sterilization: Sterilization: Sterilization describes a process Sterilization describes a process
that destroys or eliminates that destroys or eliminates all forms all forms of microbial of microbial
life and is carried out in health-care facilities by life and is carried out in health-care facilities by
physical or chemical methods .physical or chemical methods .

Disinfection: Disinfection: Disinfection describes a process that Disinfection describes a process that
eliminates many or all pathogenic eliminates many or all pathogenic
microorganisms, microorganisms, except bacterial sporesexcept bacterial spores, on , on
inanimate objects inanimate objects

AsepsisAsepsis is the state of being free from disease- is the state of being free from disease-
causing contaminants (such as bacteria, causing contaminants (such as bacteria,
viruses, fungi, and parasites) or, preventing viruses, fungi, and parasites) or, preventing
contact with microorganismscontact with microorganisms
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10. Principles of sterilization Principles of sterilization

All used instrument should thoroughly All used instrument should thoroughly
cleaned.cleaned.

The sterilizing agent to be contact with The sterilizing agent to be contact with
every surface of each item.every surface of each item.

All sterilizing equipment must be All sterilizing equipment must be
regularly serviced and maintained.regularly serviced and maintained.

Follow the manufacturer’s instruction. Follow the manufacturer’s instruction.
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11. Factors that affect the efficacy of Factors that affect the efficacy of
disinfection and sterilization disinfection and sterilization
Types of organismsTypes of organisms
Number of organismsNumber of organisms

Concentration of disinfecting agentConcentration of disinfecting agent
Presence of organic material (e.g., serum, blood)Presence of organic material (e.g., serum, blood)
Nature (composition) of surface to be disinfectedNature (composition) of surface to be disinfected
Contact timeContact time
TemperatureTemperature
pHpH
BiofilmsBiofilms
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12. Russell AD. Bacterial resistance to disinfectants: present
knowledge and future problems. J. Hosp. Infect. 1998;43:S57-68.
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13. SunlightSunlight
DryingDrying
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Physical methods

14. HeatHeat

Most reliable methodMost reliable method

Method of choice unless contraindicatedMethod of choice unless contraindicated

Factors influencing heat sterilization :Factors influencing heat sterilization :
1.1.Nature of heat (Dry / Moist)Nature of heat (Dry / Moist)
2.2.Temperature and timeTemperature and time
3.3.Number of microorganisms Number of microorganisms
4.4.Characteristics of microorganismsCharacteristics of microorganisms
5.5.Type of material to be sterilizeType of material to be sterilize
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15. Principles of different heat sterilizationsPrinciples of different heat sterilizations
Dry HeatMoist Heat
Protein
denaturation,
oxidative damage
and toxic effect of
elevated levels of
electrolytes
Denaturation and
coagulation of
protein
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16. Dry heat sterilizationDry heat sterilization
It involves heating air with transfer of heat It involves heating air with transfer of heat
energy from the air to the instrument.energy from the air to the instrument.

Alternative method particularly ,the sharp Alternative method particularly ,the sharp
instrument.instrument.
Advantage : the instrument do not rust, Advantage : the instrument do not rust,
low costlow cost
Disadvantage: time consuming and high Disadvantage: time consuming and high
temperature require.temperature require.
1616

17. Hot air oven:Hot air oven:

For laboratory glassware , glass For laboratory glassware , glass
syringe and instrument.syringe and instrument.
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18. 
Relation of temperature and time.Relation of temperature and time.
C f TIME (MINUTE)
160 320 120
170 340 60
150 300 150
140 2050 180
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Journal of American Dental Association
Vol 122 December 1991

19. Moist heat sterilization : autoclaveMoist heat sterilization : autoclave

Steam sterilization involves heating Steam sterilization involves heating
water to generate steam in closes water to generate steam in closes
chamber.chamber.

Known for destruction of all forms of Known for destruction of all forms of
microorganism because microorganism because
high penetrating capacity and give up high penetrating capacity and give up
a large amount of latent heat.a large amount of latent heat.
1919

20. AdvantagesAdvantages

The results are consistently good, and reliableThe results are consistently good, and reliable

The instrument can be wrapped prior to The instrument can be wrapped prior to
sterilizationsterilization

Time efficientTime efficient

Good penetrationGood penetration
Disadvantages:Disadvantages:

Blunting and corrosion of sharp instrumentBlunting and corrosion of sharp instrument

Damage to certain rubber goodsDamage to certain rubber goods
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21. Principle of AutoclavePrinciple of Autoclave
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22. 
Autoclave Temperature and Time Autoclave Temperature and Time
Pressure ChartPressure Chart
Sterilizer temperature
`
Pressure time
Unwrapped
items
121 15psi 15 min
132 30psi 3 min
Lighty
wrapped
132 30psi 8 min
Heavily
wrapped
132 30psi 8 min
Journal of American Dental Association Vol 122 December 1991
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23. Flash SterilizationFlash Sterilization
Overview. “Flash” steam sterilization was originally Overview. “Flash” steam sterilization was originally
defined by Underwood and Perkins as sterilization of defined by Underwood and Perkins as sterilization of
an unwrapped object at 132C for 3 minutes at 27-28 an unwrapped object at 132C for 3 minutes at 27-28
lbs. of pressure in a gravity displacement sterilizer.lbs. of pressure in a gravity displacement sterilizer.
Flash sterilization is a modification of conventional Flash sterilization is a modification of conventional
steam sterilization. steam sterilization.

Flash sterilization is considered acceptable for Flash sterilization is considered acceptable for
processing cleaned patient-care items that cannot be processing cleaned patient-care items that cannot be
packaged, sterilized, and stored before usepackaged, sterilized, and stored before use
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24. Glass beads sterilizationGlass beads sterilization::

This method employs a heat transfer This method employs a heat transfer
device.device.

The temperature achieved is of 220*c.The temperature achieved is of 220*c.

Warm–up time of at least 20 minutes Warm–up time of at least 20 minutes

The media used are glass beads, The media used are glass beads,
molten metal or salt kept in a cup.molten metal or salt kept in a cup.

Use for small instrument like Use for small instrument like
endodontic files, burs, rotary endodontic files, burs, rotary
instruments instruments

Sterilization time 10 sec. Sterilization time 10 sec.
2424

25. Low-temperature SterilizationLow-temperature Sterilization

Ethylene oxide Ethylene oxide (ETO) (ETO) (has been widely used as a low-(has been widely used as a low-
temperature sterilant since the 1950s .temperature sterilant since the 1950s .
OverviewOverview

ETO is a colorless gas that is flammable and ETO is a colorless gas that is flammable and
explosive.explosive.

parameters (operational ranges) are: gas parameters (operational ranges) are: gas
concentration (450 to 1200 mg/l); temperature (37 to concentration (450 to 1200 mg/l); temperature (37 to
63oC); relative humidity (40 to 80%)(water molecules 63oC); relative humidity (40 to 80%)(water molecules
carry ETO to reactive sites); and exposure time (1 to 6 carry ETO to reactive sites); and exposure time (1 to 6
hours)hours)
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26. 2626
Mode of Action.Mode of Action.

The microbicidal activity of ETO is considered to be The microbicidal activity of ETO is considered to be
the result of alkylation of protein, DNA, and RNA.the result of alkylation of protein, DNA, and RNA.
Uses.Uses.

ETO is used in healthcare facilities to sterilize critical ETO is used in healthcare facilities to sterilize critical
items (and sometimes semicritical items) that are items (and sometimes semicritical items) that are
moisture or heat sensitive and cannot be sterilized moisture or heat sensitive and cannot be sterilized
by steam sterilization.by steam sterilization.

27. 
Irradiation:Irradiation:
Ionizing radiationIonizing radiation
Non ionizing radiationNon ionizing radiation
2727

28. IonizindiationIonizindiation::

Include x-ray , gamma rays, and high speed Include x-ray , gamma rays, and high speed
electron.electron.

It is effective for heat labile items.It is effective for heat labile items.

Bellamy(1959) it has greater penetration properties.Bellamy(1959) it has greater penetration properties.

The lethal action is due to effect on the DNA of The lethal action is due to effect on the DNA of
nucleus and on the other vital cell compound.nucleus and on the other vital cell compound.

commonly used by industry to sterilize disposable commonly used by industry to sterilize disposable
material.material.

2828

29. Non-ionizing radiationNon-ionizing radiation
Ultraviolet Radiation (UV)Ultraviolet Radiation (UV)

The wavelength of UV radiation The wavelength of UV radiation
ranges from 328 nm to 210 nm. Its ranges from 328 nm to 210 nm. Its
maximum bactericidal effect occurs maximum bactericidal effect occurs
at 240–280 nm.at 240–280 nm.

Inactivation of microorganisms Inactivation of microorganisms
results from destruction of nucleic results from destruction of nucleic
acid through induction of thymine acid through induction of thymine
dimers.dimers.

UseUse: operating rooms, isolation : operating rooms, isolation
rooms, and biologic safety cabinets.rooms, and biologic safety cabinets.
2929

30. 3030

31. Infrared:Infrared:

Another form of dry heat sterilizationAnother form of dry heat sterilization

Most commonly use to purify air, such Most commonly use to purify air, such
as in the operating room as in the operating room
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32. Decontamination cycleDecontamination cycle
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33. Sterlization of InstrumentsSterlization of Instruments
Classified into three categories
namely -
1. Critical instruments
2. Semi critical instruments
3. Non critical instruments.

34. Recommended sterilization procedures for commonly Recommended sterilization procedures for commonly
used dental instruments / equipmentsused dental instruments / equipments
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35. 3535
Infection control in dental practice revised edition2006 S.anil Georges krygier