sterilization and infection control

1. STERILISATION AND
INFECTION CONTROL
PRESENTOR:-DR ANURAG WAGH
I MDS

2. • Many factors are important in helping to kill microorganisms and
making medical devices safe to use on patients.
• Understanding these factors will help in selecting the right process
to follow when cleaning and disinfecting or sterilizing patient care
equipment.
INTRODUCTION:

3. HISTORY
• Hungarian & O. W. Holmes (early 1950’s)
Used to wash hands in between deliveries
• Joseph Lister (1865 – 1891) :- Father of Asepsis
Used Phenols ( dilute carbolic acid).
• Antony van leewenhoek (1683) - little animalcules
• Augustino bassi (1835) discovered first pathogenic bacteria.
• Oliver Wendell Holmes in USA 1843 and Ignaz semmelweis
in Vienna 1846 - puerperal sepsis transmitted by medicos.
started washing hands in between deliveries

4. • Louis Pasteur (France) 1822-1895 -microbiology emerged as a
scientific discipline during his course of enquiry of origin of
organisms.
• Joseph Lister - aseptic technique in surgery using carbolic acid,
shifted era of laudable pus to modern aseptic techniques
• Louis pasteur developed steam sterilizer, autoclave and hot air
oven
JOSEPH LISTER LOUIS PASTEUR

5. Various Definition :-
 Cleaning :- It is a process which removes visible contamination but
does not necessarily destroy micro organisms. It is necessary
prerequisite for effective disinfection or sterilization.
 Antisepsis :-It is the procedure or application of an antiseptic solution
or an agent which inhibits the growth of microorganisms, while
remaining in the contact with them.
 Asepsis :- A process which prevents contamination of wounds & other
sites by microorganisms. E.g.: using sterile instruments for surgery.
 Disinfection- :- A process of destruction or removal of all pathogenic
microorganisms. E.g.: dipping the instruments in disinfectant like
savlon or dettol.
 Sterilization:- It is defined as the process by which an article ,surface
or medium is made free of all living microorganisms either in the
vegetative or spore state . E.g.: autoclaving all instruments before
surgery .

6.  Bactericide:
A chemical that destroys bacteria except for those in the endospore
stage.
 Sporicide:
A agent capable of destroying the bacterial spores.
 Bacteriostatic:
An agent that prevents growth of bacteria.

7. CDC & OSHA Dental Guidelines For Sterilization
Instruments
As per May 28, 1993
Dental instruments are classified into three categories - critical, semi critical, or
no critical - depending on their risk of transmitting infection and the need to
sterilize them between uses.
Critical. Surgical and other instruments used to penetrate soft tissue or
bones are classified as critical and should be sterilized after each use. These
devices include forceps, scalpels, bone chisels and burs.

8. Semi critical.-
• Instruments such as mirrors, retractors that do not penetrate soft tissues or
bone but contact oral tissues are classified as semi critical.
• These devices should be sterilized after each use.
• If, however, sterilization is not feasible because the instrument will be
damaged by heat, the instrument should receive, at a minimum, high-level
disinfection.

9. • Non critical. Instruments or medical devices such as external
components of x-ray heads that come into contact only with intact skin are
classified as non critical. Because these non critical surfaces have a
relatively low risk of transmitting infection, they may be reprocessed
between patients with intermediate-level or low-level disinfection or
detergent and water washing, depending on the nature of the surface and
the degree and nature of the
contamination .

10. Regulations for the methods of sterilization
1. Instruments that come in contact with oral mucous membrane should be
sterilized after use , preferably by autoclaving.
2. All instruments should be thoroughly cleaned before autoclaving
3. Heat stable instruments must be routinely sterilized after use by autoclaving
4. Heat sensitive instruments and equipment must be sterilized or disinfect
chemically.
5. Instruments that are to be stored should be sterilized in packing that is
approved for this purpose and correctly sealed to maintain sterility
6. High level disinfection is undertaken by immersion in 2% glutaraldehyde
solution for 10-30 mins.
7. Chlorine based products may be used to disinfect surfaces and instruments
particularly in case where other methods are not suitable

11. To achieve sterilization of any instrument three definite stages are to be
completed
 Pre sterilization cleaning
 Sterilization process
 Aseptic storage

12. Presterilization cleaning
Objective-
Removal of the organic matters,blood and saliva which provide
protective barrier for microorganisms and prevents its
destruction.
There are three methods for cleaning
1. Manual
2. Ultrasonic
3. Mechanical washing

13. MANUAL CLEANING
• It is the simplest and the cheapest method, but time consuming and difficult
to achieve.
• One prerequisite is that heavy duty gloves and glasses must be worn to
protect needle stick injury and to protect eye.
Material used for manual cleaning
1. Soaps
2. detergents

14. MECHANICAL WASHING
Principle-
• Squirting of high-pressure
jets of water with or with out
a detergent which removes
debris from instrument.
• Small instrument like burs,
blade are not suitable for this
type of cleaning.

15. STERILIZATION PROCESS
Classification of the method of sterilization
A. PHYSICAL
1. Sun Light
2. Drying
3. Heat:-
i. Dry
ii. Moist
4. Filtration
5. Gas
6. Irradiation
7. Ultra sonic cleaning

16. B. CHEMICAL
1. Phenol Derivatives : Phenol, Cresol, resorcinol, chloroxylenol
2. Oxidizing agents :Pot. Permanganate, Hydrogen Peroxide, Benzoyl
Peroxide
3. Halogens : Iodine, chlorine
4. Biguanide : Chlorhexidine
5. Quarternary Ammonium (Cationic) : Cetrimide, Zephiran
6. Alcohols : Ethanol, Isopropanol.
7. Aldehydes : Formaldehyde, Glutaraldehyde
8. Acids : Boric acid, acetic acid
9. Metallic salts ; Silver Nitrate, Zinc Sulfate, Zinc Oxide, calamine,
10. Dyes : Gentian violet, proflamine, Acriflamine
11. Furan derivatives : Nitro flurazone

17. Heat
The most common and one of the most effective methods of sterilization.
Factors influencing sterilization by heat are : -
i. Nature of heat
a. Dry
b. Moist
ii. Temperature & time
iii. No of organism present
iv. Type of material from which organism is to be eradicated

18. Sterilization packaging materials :
Type of sterilizer Packaging material
Steam Nylon plastic Cloth
tubing,Biofilm/paper peel pouch,
Chemical vapor Sterilization paper
wrap,biofilm/paper peel pouch
Dry heat Nylon plastic tubing,foil

19. A. DRY HEAT
Killing is due to :
1.Protein denaturation
2.Toxic effects of elevated levels of electrolytes
1. Red Heat : It is used to sterilize metallic objects
by holding them in flame till they are red hot.
Example : inoculating wires, needles, tips of forceps etc.
2. Flaming : The article is passed over flame
without allowing it to become red hot.
Example : Glass plates, mouth of cultures, scalpel
and glass slides.
3. Incineration :- with the help of incinerator
Infective material is reduced to ashes by burning
ex soiled dressing, bedding and
pathological materials.

20. 4. Hot air oven :
• It is used to sterilize items, which do not get damaged by high temp. such as
laboratory glass ware, flasks, scissors, all stainless steel instruments with
sharp cutting edges, (preferred) B.P. handles, Dapen dishes, mouth mirrors.
• Hot air is poor conductor of heat and poor penetrating capacity. So grease,
oils, powders plastics, rubber-containing substances should be sterilized by
other methods.
• High temp. can damage fabrics or melt them.

21. Temp. & Time: The sterilization is complete if these two
factors are achieved throughout the load.
Temperature Time(Min)
160oC 120
170oC 60
150oC 150
140oC 180

22. PRECAUTION TO BE OBSERVED WHEN
USING A HOT AIR OVEN:
• Temp. should not exceed 180°c because glass ware kept inside for
sterilization will get a smoky appearance & paper wrapper used to
cover the articles will get charred.
• The glassware kept inside should be totally dry or they will break.
• No sudden cooling of the hot air oven.
• No over loading of hot air oven.
• Instruments should be arranged in such
a way to allow free circulation of air.

23. Sterilization Control of Hot Air Oven :
• The spores of non-toxigenic strain of bacillus subtilis and clostridium
tetani are used as a microbiological test of dry heat. The spores will
be destroyed if sterilization is proper.
• Brown’s test strip with green spot is available after sterilisation a
green colour is produced.

24. B. Moist heat
Effective by denaturation and coagulation of proteins.
• TEMPERATURE BELOW 100°C
• TEMPERATURE AT 100°C
• TEMPERATURE ABOVE 100°C
A) TEMPERATURE BELOW 100°C
1. Pasteurization :
• The temperature employed for this technique is either 630C for 30mins or 720C for
15-20 seconds followed by cooling quickly to 130C.
• Method is used for heat sensitive liquid and pharmaceutical products.
• There are two types of pasteurization methods,
1.Batch method(63 degree c For 30 mins)
2.Flash method (72 degree c for 15-20 sec)
• Destroys - mycobacterium, salmonella & also Brucella.

25. 2. Vaccines of non-sporing bacteria are Heat inactivated in special
vaccine baths at 60°C for one hour.
3. Lowenstein Jensen’s media, serum & other media which contain sugar
& gelatin are sterilized in Inspissator at 80-85°C for ½ an hour on 3
successive days.- Inspissation

26. TEMPERATURE AT 100°C
(a)Boiling:
• Vegetative Bacteria killed at 90-100°c
• Time required is 60 mins
• Not effective for Sporing Bacteria
• Sterilization promoted by use of 2% Na bicarbonate
(b) Tyndallisation –
For media containing sugar or gelatin exposure of steam
at 100°c for 20 min for 3 successive days.
(c) Koch or Arnold steamer
Exposure with steam at 100°c for 90 min
ensures sterilization

27. AUTOCLAVE :
Steam is the effective means of sterilization, because of its
1. High penetrating capacity.
2. It gives of large amount of heat to surface with which it comes in
contact.
TEMPERATURE ABOVE 100°C

28. Temperature,pressure and time used for various material for autoclaving
Items
Autoclave Setting
1210c/15psi 1320c/27psi
Dressing-Wrapped in
equipment
30mins 15mins
Glass ware 15mins 3mins
Instruments(Metal) 15mins 3mins
Suture
material,tubing
20mins 10mins
Linen packs 30mins 10mins
Treatment tray 30mins 15mins

29. • Autoclave: Chamber which is filled
with hot steam under pressure.
Preferred method of sterilization,
• Temperature of steam reaches
121oC at twice atmospheric
pressure.
• Most effective when organisms
contact steam directly or are
contained in a small volume of
liquid.
• All organisms and spores are
killed within 15 minutes.
• Require more time to reach center
of solid or large volumes of liquid.

30. A TYPICAL AUTOCLAVE CYCLE:

31. Sterilization control of the moist heat :
1. Spores of bacillus stearothermophilus are used as the test organisms. Its spores require
and exposure of 12 mins at 1210c to be destroyed,
2. Brown’s test strip used as chemical indicator of moist heat

32. Agents use to avoid corrosive action of steam :
• Ammonia (Craford & Oldenburg)
• 2% Na nitrite (Bertolotti & Hurst)
• Dicyclohexylammonium nitrate (ADT)
Flash sterilization is a modification of conventional steam sterilization
(either gravity, pre-vacuum, or steam-flush pressure-pulse) in which the
flashed item is placed in an open tray or is placed in a specially
designed, covered, rigid container to allow for rapid penetration of
steam.
• Temp 134 degree c for 32psi for
3 ½ mins

33. CLASSES OF AUTOCLAVES
• Class N autoclaves (NON-VACUUM):- these are compact and they
are for sterilizing simple materials. The letter “N” stands for “naked
solid products”.
• Class B autoclaves (VACUUM):- These are compact but have high
performance level .The letter “B” stands for “big small sterilizers”.
• Class S autoclave (VACUUM):- It is an intermediate between other
two autoclaves.

34. FILTRATION
• Types of filters:-
1)Candle filters: a)glazed-chamberland ,doulton
b)unglazed-berkefeld ,mandler
2)Asbestose filters
3)Sintred glass filters
4)membrane filters : cellulose, ester
• Used for sterilisation of :
• culture media
• enzymes
• vaccines
• antibiotics

35. IRRADIATION
1.Ionizing radiation
e.g., gamma rays and high speed electrons
• cold sterilization.
• very high penetrating power.
• lethal to DNA and other cell constituents
• effective for heat labile items
Used for sterilization of plastic syringe, swabs, culture plates, cannulas,
catheter

36. 2.Non-ionizing radiation,
e.g. ultraviolet light, and infrared light. These forms of radiation can be
used to kill or inactivate microorganisms.
• Bring down the number of microorganism present in air.
• Sterilization of Operation Theaters and biological safety cabinets.
Disadvantage: Low-penetrating power

38. CHEMICLAVE:
• Chemical vapors sterilization.
• The combinations of formaldehyde 0.23%, alcohols72.38%, acetone,
ketones and steam at 138 KPa/20 psi serves as an effective sterilizing
agent.
• Microbial destruction results from the dual action of the toxic chemicals
and heat.
• It takes more time than autoclave but less time than hot-air oven that is 30
mins.
• 127 -132 degree c at 20 to 40 psi for a period of 30 minutes.
• Instruments loosely packed.

39. Advantage
• Shorter cycle
• Lack of corrosion of instruments or burs
• Availability of dry instruments as soon as cycle is over
NOTE:
Preheated before use, with the vapor reservoir sealed.
solid metal trays and sealed glass jars are unacceptable
CHEMICLAVE:

40. BIOLOGICALMONITORINGOF STERLIZATION:
process species Incubation
temperature
Steam above
atmospheric
pressure
B.stearothermophilu
s
56 c
Dry heat B.Subtilis , Cl.tetani 37 c
Subatmospheric
steam and
formaldehyde
B.stearothermophile
s
56 c
Gamma radiation B.Pumilis E601 37 c
Dental offices and hospitals-atleast weekly spore test,
but preferably daily.

41. CHEMICAL AGENTS

42. CHEMICAL METHODS
• They are used to disinfect the skin of a patient prior to surgery, and to
disinfect the hands of the operator.
• No available chemical solution will sterilize instruments immersed in it.
• Secondly, there is a risk of producing tissue damage if residual solution is
carried over into the wound while it is being used.

43. Mechanism of action of chemical disinfectants :
The mechanism of action of most of the chemicals are nonspecific and
complex but most of them effect microorganisms by one of the following
mechanisms.
1)Protein coagulation.
2) Disruption of cell membrane .
3) Removal of free sulfhydryl groups
4) Substrate competition for enzyme

44. Spaulding(1972) Classification of Chemicals
The chemicals are classified as high, intermediate and low level
disinfectant based on effectiveness and contact time of the solution and the
biocidal activity of and agent against bacterial spore, M.tuberculosis and
vegetative bacteria.
1. High level disinfectants :
The chemical which is active resistant for bacterial spores and all other
microbial forms are termed as high level sterilants. Ethylene oxide gas and
immersion glutaraldehyde solutions are high level sterilants. Prolonged
immersion time of 6 to 10 hrs are required to achieve sterilization with 2%
and 3.2% preparation.

45. 2. Intermediate level disinfectants :
These chemicals may not inactive bacterial spores during routine usage but
they do destroy other forms of microbes particularly tubercle bacilli.
Formaldehyde, chlorine compounds, iodophor, alcohols and phenolic
compounds are these types of disinfectants.
3. Low level disinfectants :
Provide narrowest antimicrobial range and include quaternary ammonium
compounds, simple phenols and detergents. Such material are use for
cleaning purpose but their microbial activity is too low to consider them as
disinfectants or sterilants.

46. EPA AND ADA CLASSIFICATION OF CHEMICALS
1. Disinfectant/Steriliants :
Use for sterilization or high level disinfection, depending on contact time.
2. Hospital disinfectant with tuberculocidal activity :
Use to achieve intermediate disinfection.
3. Non-tuberculocidal hospital disinfectants :
Use to achieve low level disinfectant.
4. Sanitizers :
Use of chemicals that maintain the microbial flora at a safe public-health
level. This chemical have no application in dentistry

47.  Ethylene oxide Gas Sterilization
• Eo has been widely used as a low temperature sterilant since 1950s
• Mechanism of action: It destroys micro-organisms by alkylation and cause
denaturation nucleic acids of micro-organisms.
USES
• It is excellent sterilizer for heat sensitive items.
Plastics, rubber & photographic equipments can
be sterilized by this method.
• Also used for mass sterilization of disposable
items, plastic syringes, needles , catheters ,
blades etc.
DISADVANTAGES It is highly toxic, inflammable
mutagenic and carcinogenic so should not be used
when heat sterilization of an object is possible

48. Sterilization by low temperature steam and
Formaldehyde :
• This method uses a combination of dry saturated steam and formaldehyde
to kill bacteria, spores and most viruses.
• Destruction of microorganisms is due to dual action, by the heat and
formaldehyde.
• The required combination of temperature and pressure is 1270c to 1320 at
20 to 40 psi for 30 mins.
• It is suitable for heat sensitive material and
instruments like rubber and plastic material.
• It requires provision of adequate ventilation to
expel chemical vapors released from the
chamber.

49. A new low temperature sterilization technique
Hydrogen peroxide plasma sterilizer
• Based on a patented process involving the generation of a low-temperature
hydrogen-peroxide gas plasma.
• Effectively sterilizes most heat- and moisture-sensitive medical devices and
surgical instruments like rubber catheter, gloves, plastic syringe etc.
• Only disadvantage of this technique is its cost. So it can’t be used as routine
sterilizer.

50. 1. ALDEHYDE COMPOUNDS
• Aqueous solution of formaldehyde (formalin) and
• Glutaraldehyde (cidex) are effective disinfectants
a. Formaldehyde:
• This is a broad-spectrum antimicrobial agent, which is used for disinfection.
• It is a hazardous substance, inflammable and irritant to the eye, skin and
respiratory tract.
• This is used to upto 500c and has limited sporicidal activity.
• It is used for large heat-sensitive equipment such as ventilators and suction
pumps excluding rubber and some plastics.
• To sterilize bacterial vaccine
• To prepare toxoids from toxin.

51. b. Glutaraldehyde:
• It is toxic, irritant and allergenic.
• It is a high level disinfectant.
• It is applicable where heat cannot be used.
• It is active against most vegetative bacteria (including M. Tuberculosis) and
some viruses (including HIV and HBV), fungi and bacterial spores.
• It is frequently used for heat sensitive material.
• A solution of 2 percent glutaraldehyde (Cidex), requires immersion of 20
minutes for disinfection; and 6 to 10 hours of immersion for sterilization.
ARTICLES STERILISED:
• Corrugated rubber anesthetic tubes
• Face masks
• Plastic endotracheal tubes
• Metal instruments
• Polythene tubing

52. 2. ALCOHOLS
• Ethanol and isopropyl alcohols are frequently used as antiseptic. Alcohols possess
some antibacterial activity, against some Gram-positive and negative bacteria, and
especially against M tuberculosis.
• The alcohol must have a 10 minute contact with the organism.
• They are frequently used for skin antisepsis prior to needle puncture. Their benefit
is derived primarily in their cleansing action. Alcohol is sometimes used as a rinse
following a surgical scrub. Its effectiveness lies in the solvent action and not in its
antibacterial properties.
• Ethanol (Ethyl alcohol) is employed
in the concentration of 70 percent as a skin antiseptic.
• It has poor activity against bacterial spores, fungi, and
viruses.

53. 3. PHENOLIC COMPOUNDS
• Phenol itself toxic to skin and bone marrow.
• The phenolic compounds were developed to reduce their side effects but are
still toxic to living tissues.
• These compounds, in high concentration, are protoplasmic poison, and act
by precipitating the proteins and destroy the cell wall.
• These compounds are used for disinfection of in animate objects such as
walls, floors and furniture.
• They may cause damage to some plastics, and they do not corrode certain
metals, such as brass, aluminium and carbon steel.

54. 4. AQUEOUS QUARTERNARY AMMONIUM COMPOUNDS
• Benzalkonium chloride (Zephiran),dibenzalkonium chloride are the most
commonly used antiseptic.
• Their spectrum of activity is primarily Gram-positive bacteria. It is well
tolerated by living tissues.
• It is not widely used because of its narrow spectrum of activity.
• According to ADA Council on dental therapeutics(1978) due to low
bactericidal activity of these compounds. They are no longer in use as
disinfectant.

55. 5. IODOPHOR COMPOUNDS
• Most effective antiseptics.
• Iodine is complexed with organic surface-active agents, such as,
polyvinylpyrrolidone (betadine, isodine).
• Their activity is dependent on the release of iodine from the complex.
• The surface agent is film forming; this prevents the solution form staining
clothes or skin.
• These compounds are effective against most bacteria, spores, viruses, and
fungi.
• These are the most commonly used surface disinfectants along with
hypochlorite.
• Concentrated solutions have less free ioidine.
• Iodine is released as the solution is diluted.
• An appropriate dilution is 1 : 2 : 3 parts
of iodophor and distilled water, respectively.

56. 6. Chlorine compounds :
• The most commonly used chlorine-containing compounds are hypochloride
solution and chlorine dioxide.
• The CDC has recommended the use of 0.005% to 0.5% sodium
hypochloride as an effective agent in inactivating HBV.
• It is corrosive to metal and very irritating to skin and other tissues.

57. 7. Biguanide :
• Most commonly used biguanide compound is chlorhexidine.
• It is a powerful non-irritating antiseptic that disrupts bacterial cell
membrane.
• It persists on skin for longer period of time and that is why it is extensively
used for surgical scrubbing, neonatal bath, mouth wash and a general skin
anti-septic.

58. 8.Metallic salts
• Salts of heavy metals have germicidal action. The salts of silver, copper,
and mercury are used as disinfectants.
• They are protein coagulants and have the capacity to combine with free
sulfhydryl groups of cell enzymes.
• Copper salts are used as fungicides
9.DYES
• Aniline Dyes And Acridine Dyes
• Skin & wound antiseptics
• Bacteriostatic in high concentrations.
• Aniline dyes :-in use are brilliant green malachite green crystal violet.
• More active against gram positive organisms
• Lethal effect on bacteria is due to reaction with the acid groups in the
bacterial cell
• The Acridine Dyes :-more Active Against Gram Positive Organism.Eg.
Proflavine Acriflavine Euflavine
• They impair the DNA complexes of the organisms and thus destroy the
reproductive capacity of the cell

59. Sterilization of handpiece
SHOULD DO
• Remove bur and disconnect handpiece from chair.
• Wipe handpiece with alcohol.
• Locate appropriate hole and spray lube for 2-3 seconds.
• Attach handpiece to swivel unit and insert bur.
• Run handpiece for 30 seconds to eliminate lube.
• Wipe handpiece with alcohol.
• Insert in autoclave bag paper on at least one side of bag. Load in autoclave
with cellophane side down.
• Remove from autoclave immediately after all cycles are complete.
• Always allow cooling to room temperature, paper side up.
• Do not force cool with water or other means.

60. SHOULD NOT DO
• Do not immerse hand piece in any solvent, cleaner or ultrasonic
solution.
• Do not clean hand piece in ultrasonic cleaners or dry heat sterilizers.
• Do not exceed temperature of 135°C.
• Do not use chemical disinfectants, when combined with heat of the
autoclave, disinfectants may significantly reduce hand piece life .
• Do not use all cellophane bags

61. DISINFECTION IN OPERATION
THEATER

62. DISINFECTION IN OPERATION
THEATERS
• Operating room should have 2 sets of doors.
• Operation theater ceiling , walls & flooring should be disinfected
regularly with antiseptics & fumigated regularly.
• Operation theater access should be restricted to OT personels only.
• Operation theaters are disinfected by fumigation
• OT personel should do a special scrub & dressing before entering to
OT.

63. PRINCIPLES IN DESISN OF OPERATION
THEATER:
A) OUTER RECEPTION AREA INCLUDES:
1.The reception office
2.The reception waiting room for patients & relatives
3.An area for troleys storage
4.An area of hanging gowns for relatives & parents
B) A “CLEAN ZONE”:
Which is wide clean corridor giving access to anesthetic room
recovery room, clean storage area, emergency autoclave, x-ray
machine

64. C)THE OPERATING THEATER :
1.OT should have a double door entrance from anesthetic room & a
double door entrance to the clean corridor.
2.There should be 2 small doors one towards store room from sutures
dressings etc are taken & one from srub room into the OT.
3.Temperature should range from 19 degree C to 22 degree C with
humidity of 45-55%
4.Adequate no. of power plugs should be there .
5.Operating table should be regularly checked for smooth raising &
lowering of table & for tilting of table for trenderlenburg position &
lateral tilt position
6.OT lights should also be adjustable easily with removable handles so
that it can be sterilized and handled by OT personels
7.Tubings and devices should be covered with the disposable sheets
which can be removed easily after use.
8.OTs should be spacious enough so that troleys and staff can move
around table easily.

65. FUMIGATION OF OPERATION THEATER
• The O T is disinfected by fumigation .
• Fumigation can be achieved by fumigators as well as potassium
permanganate reaction technique . some times methanol is also used but
highly inflamable.
• Fumigation chemical used is 40% FORMALINE
• Fumigator is set for 30 mins with timer adjustments in the instruments
• The operating room is kept closed with fumes in it for 12 to 24 hrs.then the
fumes are let off.

66. • Currently other methods are used for fumigation of operation theatre
Envodil- stabalized hydrogen peroxide 11%w/v
diluated silver nitrate solution 0.01%w/v
purified water IP
Aldekol- formaldehyde 6%w/v
glutaraldehye 6%w/v
benzalkonium chloride 5%w/v

67. Monitoring of fumigation
• Swabs are collected from various location after every 2 weeks
from ot and they are as follows:-
1. Operation tables at head end
2. Over head lamp
3. Four walls
4. Floor below the head end of the table
5. Instruments trolley
6. Ac duct

68. • CONTROL OF AIR QUALITY :
1.In an univentilated operating areas colony forming units are upto 3000 per
cu.mtr., but with proper ventilation it can be reduced upto 200 CFU per
cu.mtr.
2.Single layer & double layer ventilation systems are installed in OT`s now-
a-days with micropore system & unidirectional non turbulent flow reduces
CFU & controls temperature between 19 to 22 degree celsius & humidity
45 to 55 %.
• THE SCRUB ROOM:
1.Itshould have 2 doors one from corridor & one to OT
2.Sinks with taps & soap holders that can be manipulated with elbows
should be present
3.Sink design should be such that splashing on clothes is prevented
4.Antislip floors easily cleaned shelves for gown packs & gloves should be
present
5.Brushes for cleaning fingernails should be available

69. • Preoperative showering with hexachlorophene has shown reduction
in wound infection.
• Short preoperative hospital stay reduces pathogenic bacteria on skin
and nasal carrier state.
• Shaving the surgical area

70. PATIENT SKIN PREPARATION
MATERIALS COMMONLY USED
• The iodophors (e.g., povidone-iodine), alcohol containing products,
and chlorhexidine gluconate are the most commonly used agents.
• Alcohol is readily available, inexpensive, and remains the most
effective and rapid-acting skin antiseptic. Aqueous 70% to 92%
alcohol solutions have germicidal activity

71. • Before the skin preparation of a patient is initiated, the
skin should be free of gross contamination (i.e., dirt, soil,
or any other debris)
• The patient’s skin is prepared by applying an antiseptic
(savlon, cetrimide or povidon iodine) scrub in concentric
circles, beginning in the area of the proposed incision
and medial to lateral for 2 minutes
• Then mop the area with dry sponge or sponge soaked in
normal saline to remove the residues of antiseptic agent
• Finally area is painted with 5% povidon iodine solution
and should be kept on skin for atleast 2 minutes.

72. • To hasten drying of skin alcohol may be painted on area
without friction before a self adhering tape is applied.
• The prepared area should be large enough to extend the
incision or create new incisions or drain sites.
• Oral cavity should be prepared again with chlorhexidine or
povidon iodine 5 %solution to achieve maximum antisepsis
and prevent wound contamination.
• The prepared area is the surgical area/field and needs to be
isolated from rest of body area and environments to prevent
cross contamination.

74. • DRAPING THE PATIENT
• Turban draping

75. • Commercially available drapes
• Once a drape has been positioned, it should not be repositioned.
• The surgeon should maintain 12” away from the O.R. table when
performing the draping procedure .
• Surgeon should not reach across an undraped O.R. table in order to
perform a draping procedure.
• Non perforating towel clips should be used to keep towels or drapes
• Beckhaus towel clip
• Pinchter type towel clip

77. HAND SCRUB THECHNIQUES:
• It is the first &most important step towards aseptic technique
• The purpose of hand scrub is a 2 fold technique:
1.To remove the superficial contaminants & loose
epithelium by mechanical action of brush;
2.To reduce the bacterial count on the skin
• All jewellery should be removed before washing hands
• Nails are checked for cleanliness & all gross subnail contaminants
should be removed.
TYPES OF HANDWASHING.

78. AREA TO BE SCRUB

81. Gowning
• Hold the gown away from your body, high enough to be wel above
floor
• Allow it to drop open, put your arms into the arm holes while
keeping your arms extended .
• Then flex your elbows and abduct your arms .
• Wait for circulating nurse to help you.
• She will grasp the inner sides of the gown at each shoulder and pull
them over your shoulder

84. Aseptic storage
Crump (1966) reported that the storage of instruments is also a problem. The pattern of
storage varies from place to place. They are either stored in drawers, or in containers, in
packs or sterilized trays. The maintenance of sterility during transportation and storage is of
utmost importance.
1. Packs should be stored with the following considerations
2. Instruments are kept wrapped until ready for use .
3. To reduce the risk of contamination, sterile packs must be handled as little as possible.
4. Sterilized packs should be allowed to cool before storage; otherwise condensation will occur
inside the packs.
5. To prevent contamination from rodents, ants, and cockroaches, the store must be subjected
to adequate pest control .
6. Materials should be stored at least 8” off the floor and 18” from the ceiling
7. Sterile packs must be stored and issued in correct date order. The packs, preferably, are
stored in drums which can be locked. Preset trays and cassettes, are useful as, the
instruments can be organized as per the procedure

85. CONCLUSION
Antibiotics, both prophylactic and therapeutic, can
never reduce the role of STERILIZATION AND
ASEPTIC PRECAUTIONS.
Protocols with regards to instrument sterilisation,
equipment maintenance, air filtration, ventilation
and staff behaviour are essential along with a
Regular Staff education.”

86. REFRENCES
• Anantnarayan-Textbook of Microbiology
• LJ Peterson-Cotemporary Oral & Maxillofacial Surgery
• Laskin-Textbook of Oral & Maxillofacial Surgery
• Neelima Malik-Textbook of Oral & Maxillofacial Surgery
• Fonseca-vol-2, edition 3
• R.M Borle.

87. Thank you..!