asepsis in dentistry, infection control, sterilization, heat and cold methods of sterilization

1. ASEPSIS IN DENTISTRY
DEPARTMENT OF PERIODONTICS AND IMPLANTOLOGY
MALLA REDDY DENTAL COLLEGE FOR WOMEN
PRESENTED BY
PODUPATI PRANAVI
MDS 1ST YEAR
1

2. INDEX
 INTRODUCTION
 TERMINOLOGY AND DEFINITION
 HISTORY OF ASEPSIS
 METHODS OF STERILIZATION
 PHYSICAL METHODS
 CHEMICAL METHODS
 SPAULDINGS CLASSIFICATION
 LEVELS OF DISINFECTION
 STERILIZATION AND DISINFECTION IN
HEALTH CARE SETTINGS
2

3. INTRODUCTION
 All basic and invasive procedures in dentistry involve contact
by a surgical instruments with patients sterile tissues or
mucous membranes. A major risk of all such procedures is
introduction of pathogenic microbes leading to infection .
 Failure to provide proper aseptic conditions like proper
disinfected or sterilized equipment may lead to transmission
of pathogenic microbes through medical and surgical devices.
3

4.  Modes Of Transmission :
1)Direct contact : Direct contact with blood, oral fluids or other
patient materials.
2)Indirect contact with contaminated objects : Instruments
equipment or environmental surfaces.
4

5. 5
 3)Inhalation of droplets containing microorganisms
generated from an infected person and propelled a
short distance or aerosols.

6. TERMINOLOGY AND DEFINITIONS
 ASEPSIS:
Asepsis is a state of complete absence of viable pathogenic
microorganisms in any environment.
 STERLIZATION:
A process by which all microbe forms are destroyed
(Patterson,1932).
Sterilization is a process by which an article, surface or medium is freed
of all living microorganisms either in vegetative or spore state.
 DISINFECTANT:
A chemical used on non vital objects to kill surface vegetative
pathogenic organisms, but not necessarily spore forms and viruses
(Patterson,1932).
6

7.  ANTISEPTICS :
A chemical that is applied to living tissues such as skin or
mucous membranes to reduce number of micro organisms
present , through inhibition of their activity or destruction
(Patterson ,1932).
 BACTERIOSTATIC AGENTS :
They prevent the multiplication of bacteria which may
however , remain alive.
 BACTERICIDAL AGENTS :
These are substances that can kill bacteria .
A chemical which is bactericidal at a particular concentration
may become bacteriostatic at higher dilution .
7

8. HISTORY OF ASEPSIS
 JOSEPH LISTER conducted studies on prevention of
wound infection , made between 1865 to 1891 .
 Louis Pasteur developed the GERM THEORY OF
DISEASE , this provided basis for understanding wound
sepsis.
 Lister initially applied dilute carbolic acid (phenol) to
contaminated wounds and then progressed to its
application in all surgical wounds, as well as in the
operating room by nebulization of solution .
 In 1890s further developments in Listerian asepsis
occurred rapidly with advent of steam sterilization ,
surgical masks ,sterile gowns, sterile gloves, sterile
drapes .
8

9.  Despite modern methods of sterilization and use of sterilization and the use
of aseptic techniques, microorganisms are introduced into surgical sites .
 Studies by Dillon , Posthletwait and Bowling (1969), Jepson(1973) and
Krizek and Robson(1975) have implicated bacteria introduced into the
operative wound at time of surgery as the cause of many postoperative
infections .
 A report by the AD Hoe Committee of the Committee of Trauma, National
Academy of Science (1964) and a study by Cruse and Ford (1973), both of
which reviewed over 15000 surgical cases emphasized the importance of
meticulous surgical techniques and asepsis for prevention of infection .
 Although it is probable as suggested by Elek and Cohen (1957) , that most
postoperative infections today result from faulty surgical technique .
 The importance of disinfection , asepsis and in minimizing the patients
exposure to pathogenic bacteria cannot be overemphasized. 9

10. METHODS OF STERILIZATION
Methods used for sterilization are
1) PHYSICAL METHODS
 DRY HEAT
 MOIST HEAT
 RADIATION
2) CHEMICAL METHODS
 SURFACE ACTIVE AGENTS
 PHENOLS
 ALCOHOLS
 OXIDIZING AGENTS
HALOGENS - IODINE , IODOPHORS
CHLORINE ,HYPOCHLORITE
HYDROGEN PEROXIDE
 ALDEHYDES
FORMALDEHYDE
GLUTARALDEHYE
 GASES
10

11. PHYSICAL AGENTS
HEAT:
 Applying heat to an object is the most reliable method of
sterilization.
 Materials that may be damaged by heat can be sterilized by
exposing them to low heat for long periods or repeated cycles.
 Two types of heat :
dry heat
moist heat
11

12. The FACTORS INFLUENCING STERILIZATION by heat are :
 Nature of heat: dry or moist
 Temperature and time
 Number of microorganisms present
 Characteristics of organisms, such as species ,strain ,
presence of spores
 Type of material from which the organisms must be eradicated
12

13. MECHANISM OF ACTION :
 Dry heat causes
protein denaturation
damage by oxidizing molecules
toxic effect of elevated levels of electrolytes .
Cell death
 Moist heat causes
denaturation and coagulation of proteins .
13

14. 14

15. THERMAL DEATH TIME :
 The time required for sterilization is inversely proportional
to temperature of exposure and can be expressed as thermal
death time .
 Time required for sterilization -1/temperature of exposure
 This is minimum time required to kill a suspension of
organisms at a predetermined temperature in a specific
environment.
15

16. DRY HEAT STERLIZATION :
FLAMING
 Sterilized by holding them over bunsen flame till they
become red hot .
 An inoculating loop or wire , the tip of forceps ,
searing spatulas .
16

17. INCINERATION
 Incineration is a high temperature dry oxidation process that
reduces organic and combustible waste to inorganic ,
incombustible matter and results in very significant reduction
of waste volume .
INDICATIONS:
 For destroying biomedical waste .
 Suitable only for those articles that have to be disposed.
 Used to treat wastes that cannot be recycled or reused or
disposed off in a landfill site.
CONTRAINDICATIONS
 Burning of polystyrene materials emits dense smoke, and
hence they should not be incinerated
 Non risk health care waste
 Radio active waste
17

18. WASTE DISPOSAL
 Segregation is the key to hospital waste management.
1. It allows different categories of waste and placing them in
different containers
2. Reduction in the chances of infections
3. The bags should be labeled , bearing the international
biohazard symbol and the waste after segregation should be
stored in color coded bags
18

19. 19

20. Syringe needle destroyer:
It allows complete removal
of needle from syringe hub
20

21. WASTE CATEGORIES CONTENTS COLOUR CODING FINAL DISPOSAL
General Waste Stationary waste, cartons,
boxes
Green Corporate bin
Infected Waste Used cotton, guaze , excised
tissue, extracted teeth.
yellow Incineration
(CBWTF)
Cyclables Plastics , disposable
syringes.
Red Identify buyer
(CBWTF)
Sharps Blades, needles. White Landfill.
21

22. TYPES OF INCINERATORS:
•Double chamber pyrolytic incinerator
•Single chamber incinerator
•Rotary kilns
22

23. DOUBLE CHAMBER PYROLYTIC INCINERATOR:
Also called as CONTROLLED AIR INCINERATOR or
DOUBLE CHAMBER INCINERATOR .
 This is most reliable and commonly used process for health
care waste.
It comprises of
 pyrrolytic chamber
 post combustion chamber.
Uses :
 Infectious waste
 anatomical waste
 sharps
23

24. 24
DRAWBACKS :
•Relatively expensive equipment
•expensive to operate and maintain
•well trained personnel is required .

25. SINGLE CHAMBER INCINERATOR :
 This can be used for health care waste if a pyrolytic
incinerator cannot be afforded.
 It is simplest form
PROCEDURE :
 A good fire should first be established on ground underneath
the drum.
 One bag of waste should be lowered into the drum. Wood
should be added to the fire until the waste is completely burnt.
 After burning is complete , the ashes from both fire and waste
itself should be collected and buried safely .
25

26. This type of incinerator treats waste in batches .
Loading and de-ashing operations are done
manually .
Drawbacks:
•Chemical and pharmaceutical residue will
persist if temperature does not exceed 200 ̊ c.
•This process will cause emission of black
smoke, fly ash and potentially toxic gases.
•Causes air pollution.
26

27. ROTARY KILN :
 comprises of rotating oven
post combustion chamber.
 axis 3- 5 degree slope .
 rotates 2- 5 times per minute and is charged with waste at the
top.
 The gases produced in the kiln are heated to high
temperatures to burn off gaseous organic compounds in post
combustion chamber
Temperature – 800-1200̊ C
1200 - 1600 degree c .
Capacity - 0.5 - 3 tonnes /hour
27

28. DISADVANTAGE:
•well trained
personnel required
•Equipment and
operation costs are
high
•Energy consumption
is high .
28

29. HOT AIR OVEN
 This is widely used method of sterilization by dry heat .
 Sterilization is achieved by conduction .The heat is absorbed
by the surface of the item to be sterilized ,which than
penetrates to the centre until the entire item reaches the
desired temperature.
 A holding period of 160ºC for 2 hrs -required to sterilize
29
CONTRAINDICATIONS :
Rubber materials except silicon rubber , will not
withstand the sterilizing temperature

30. INDICATIONS
 Swabs and pharmaceutical products like liquid paraffin,
dusting powder etc .
 glass ware and syringes
30

31. •Chamber should be fitted with a fan to provide
forced air circulation throughout the oven
chamber
•temperature indicator
•control thermostat
•Timer
• open mesh shelving
Preparation of load :
1) No overloading
2) Articles and glassware :clean and dry.
3) Test tubes and flasks : wrapped in paper.
4) Cotton plugs : May get charred at 180 degree c .
5) Heat sensitive materials : Dry heat sterilization is slow and not suitable
for heat-sensitive materials like many plastic and rubber items.
31

32. TEMPERATURE CYCLES
 160 ̊ C - 120 MINUTES
 170 ̊ C - 40 MINUTES
 180 ̊ C - 20 MINUTES
 COOLING :It may take upto several hours and do
not attempt to open the chamber door until the
chamber and load have cooled below 80degree c.
 Glassware is liable to crack if cold air is admitted
suddenly while it is still very hot.
32

33. ADVANTAGES DISADVANTAGES
 doesn’t corrode materials
 low operating cost
 prolonged cycles with high
temperatures which is not
suitable
33

34. MOIST HEAT STERILIZATION:
AUTOCLAVE :
Autoclaving is the process of sterilization by saturated steam
under high pressure above 100̊ c.
Steam sterilization is carried out in pressure chamber called
autoclave .
It is an efficient, reliable and rapid method of sterilization .
34

35.  Pressure chamber consists of-
It is a large cylinder (vertical or
horizontal). It is made up of gunmetal or
stainless
A steam jacket (water compartment)
 The lid is fastened by screw clamps and
lid bears the following
A discharge tap for air and steam
discharge
A pressure gauge
A safety valve
 An electrical heater is attached to the
jacket, that heats the water to produce
steam.
Various components of autoclave :
In simplest form of laboratory autoclave comprises of 3 parts
35

36. PRINCIPLE OF AUTOCLAVE :
 The principle of autoclave is that water boils when its vapor
pressure equals to that of surrounding atmosphere .
 When pressure inside a closed vessel increases , the
temperature at which water boils also increases .
 Steam condenses to water and gives up its latent heat to
surface when it comes in contact with a cooler surface .

 The water of condensation ensures moist conditions for killing
of exposed microorganisms.
 Temperature 121̊ c at 15lbs of pressure for 15 minutes
36

37.  RECOMMENDED TEMPERATURE AND
DURATION:
METHOD TEMPERATURE ⁰ C HOLDING TIME
(in minutes)
AUTOCLAVE 121 15
126 10
134 3
BRITISH PHARMACOPEIA 1988,
EUROPEAN PHARMACOPEIA 1990
37

38. PROCEDURE :
 The cylinder is filled with sufficient water and the material to be
sterilized is placed on tray.
 The lid is closed with the discharge tap open. The heater is put on .
Safety valve is adjusted to the required pressure.
 After boiling of water and air mixture is allowed' to escape till all
the air has been displaced.
 The discharge tap is now closed. The steam pressure rises inside
and when it reaches the desired set level (15 pounds (lbs) per square
inch), the safety valve opens and the excess steam escapes.
38

39.  After the holding period, the heating is stopped and
autoclave allowed to cool till the pressure gauge indicates
that the pressure inside is equal to the atmospheric
pressure. The discharge tap is opened slowly and air is
allowed to enter the autoclave. Instrument packs should
be allowed to dry inside the sterilizing chamber before
removing and handling. The lid is now opened and the
sterilized material removed.
 Note: The domestic pressure cooker works on the same
principle and may used for sterilization of small articles
in clinics.
39

40. Indications
 For sterilizing culture media and other laboratory supplies
,aqueous solutions , rubber materials , surgical dressing,
pharmaceutical products .
contraindications
 It is an efficient, reliable and rapid method of sterilization
except for oils greases and powders .
40

41. ADVANTAGES: DISADVANTAGES:
 It has more penetrative
power than dry air.
 economical
 short cycle time
 It moistens the spores
(moisture is essential for
coagulation of proteins),
 easily monitered
 no extra exhaust chemicals
are needed.
 Heat & moisture may act
overtime to dull & rust
instruments, weaken
certain plastics & rubber
items.
 Additional problems:
operator error, faulty
packaging, improper
loading & inadequate
operation of the equipment
 dulling of unprotected
cutting edges
41

42. In gravity displacement sterilizer ,
steam is admitted through steam
lines ; steam generator or self
generation of steam within the
chamber .
Unsaturated air is forced out of the
chamber through a vent in the
chamber wall .
Disadvantage :
Trapping of air
Error in packaging of items or
overloading the sterilizer chamber
can lead to failure of sterilization.
Types of autoclave :
GRAVITY DISPLACEMENT AUTOCLAVE
42

43. PREVACUUM STERILIZER :
 These are fitted with a pump to create a vacuum in the chamber and ensure
air removal from sterilizing chamber before the chamber is pressurized
with steam .
 Prevacuum sterilizers should be tested periodically for adequate air
removal , as recommended by manufacturer .
 Air not removed from the chamber interferes with steam contact .
Relative to gravity displacement ,this
allows faster and more positive steam
penetration throughout the entire load.
43

44. FLASH STERILIZATION :.
defined by Underwood and Perkins as sterilization of an
unwrapped object at 132º C for 3 mins at 27-28lbs. of
pressure in a gravity displacement sterilizer
Uses:
 Flash sterilization is considered acceptable for processing
cleaned patient-care items that cannot be sterilized, and stored
before use.
 It also is used when there is insufficient
time to sterilize a item by the preferred package method
44

45. SUPERIORITY OF MOIST HEAT OVER
DRY HEAT:
•Moist heat is more lethal than dry heat.
•Availability of latent heat as steam
condenses.
•Density of steam is 1/2 of air so better
penetration.
45

46. RADIATION:
 Two types of radiation ;non ionizing and ionizing radiation .
Non ionizing radiation :
 Includes Infrared and ultraviolet (uv) rays .
 The effectiveness of uv light is lethal and mutagenic agent is
closely correlated with its wavelength .
 The most effective bactericidal wavelength is 240-280nm
range, with the optimum is about 260 nm ,the wavelength
most effectively absorbed by DNA and this interferes with
DNA replication.
46

47. Indications
 UV radiation is used to disinfect enclosed areas ,such as
entryways, hospital wards, operating theatres, laboratories and
in ventilated safety cabinets, in which dangerous micro-
organisms are being handled.
 Infrared radiation is used for rapid mass sterilization of
prepacked items.
 eg. Syringes, catheters
47

48. Ionizing radiation ;
 Includes x rays , gamma rays and cosmic rays.
 They have high penetrating power and are highly
lethal to all cells including bacteria . ionizing
radiation damages the DNA.
48
Indications
For sterilization of packaged disposable
articles , such as plastic syringes,
intravenous lines , catheters, and gloves
that are unable to with stand heat .

49. Chemical methods
 The chemicals agents used are commonly called
disinfectants.
 The chemical agents , based on microbicidal ability
are classified into 4 groups.
low level ,
intermediate level ,
high level disinfectant
chemical sterilant.
 Antiseptics are low to intermediate level disinfectants
that are less toxic to the body surfaces; hence can be
applied to skin, open wounds and mucosa.
49

50. CHARACTERISTICS OF A
DISINFECTANT
An ideal antiseptic or disinfectant should :
 have a wide spectrum of activity and must be effective against
a wide variety of infectious agents (gram positive and gram
negative bacteria, acid fast bacteria , bacterial endospores,
fungi and viruses) .
 be active at high dilutions and in presence of organic matter.
 it should be effective in acid as well as alkaline media.
 have a speedy action.
 have high penetrating power
 be stable
50

51.  be compatible with other antiseptics and disinfectants
 not corrode materials
 not cause local irritation
 not interfere with healing
 not be toxic if absorbed into circulation
 be cheap and easily available
 be safe and easy to use
such a ideal chemical is yet to be found
51

52. CLASSIFICATION
Based on mechanism of antimicrobial action
 Agents that denature proteins
Alcohols
 Agents that damage the cell membrane
phenols
Surface active disinfectants
 Agents that modify functional groups of proteins and nucleic
acids
oxidizing agents – halogens, hydrogen peroxide
alkylating agents – formaldehyde, glutaraldehyde
52

53. AGENTS THAT DENATURE PROTEINS
ALCOHOLS
 Disinfectants and antiseptics.
Ethyl alcohol (Ethanol),
Isopropyl alcohol (isopropanol)
Uses
53

54. Advantages Disadvantages
Bactericidal, tuberculocidal,
fungicidal, virucidal
• Fast-acting
• Noncorrosive
• Non staining
• Used to disinfect small
surfaces, such as rubber
stoppers on medication
vials
• No toxic residue .
• Not sporicidal
• Affected by organic matter
• No detergent or cleaning
properties
• Not EPA registered
• Flammable
• Evaporates rapidly, making
contact time compliance
difficult
• Not recommended for use on
large surfaces.
54

55. AGENTS THAT DAMAGE CELL
MEMBRANE:
1.PHENOLS
 Phenol (carbolic acid ) was the first widely used antiseptic and
disinfectant , was introduced in surgery in 1867 by Joseph
Lister (The Father of antiseptic surgery ).
 It is now rarely used as an antiseptic because it irritates the
skin and has a disagreeable odor .
 cresol, chloroxylenol
55

56.  Lysol - Commercial preperation of mixture of phenolics
 Chloroxylenol -It is an active ingredient of dettol. It is less
toxic and less irritant
56

57. Advantages Disadvantages
• Bactericidal, tuberculocidal,
fungicidal, virucidal
• Inexpensive (in dilutable
form) and EPA registered
• Non staining
• Not flammable
• Not sporicidal
• Depigmentation of skin
caused by certain phenolics
57

58. 2. SURFACE - ACTIVE AGENTS
 Surfactants are the compounds that lower the surface tension
(or interfacial tension ) between two liquids or between a
liquid and a solid.
 They may act as detergents , wetting agents.
58

59. CATIONIC AGENTS :
 Quaternary ammonium compounds are most important
cationic compounds.
 Acetyl trimethyl ammonium bromide OR cetrimide -
(cetavlon and savlon)
 Benzalkonium chloride (zephiran )
59

60. Advantages Disadvantages
 Not sporicidal
 In general, not
tuberculocidal and virucidal
against nonenveloped
viruses
 A few reports documented
asthma as a result of
exposure to benzalkonium
chloride
 Affected by organic matter
 Bactericidal, fungicidal,
virucidal against
enveloped viruses (eg,
HIV)
 Good cleaning agents
 Surface compatible and
EPA registered
 Persistent antimicrobial
activity when
undisturbed
 Inexpensive (dilutable
form).
60

61. ANIONIC AGENTS :
 These includes soaps .
 Anionic surfactants such as common soaps usually have
strong detergent but weak microbial properties.
 sodium lauryl sulphate
61

62. AMPHOLYTIC (AMPHOTERIC )
COMPOUNDS :
 They possess antimicrobial activity of cationic compounds
and detergent properties of anionic compounds.
 These are known as Tego compounds which is the commercial
name of series of disinfectants ..
Uses:
 They are used as antiseptics, but are known to cause allergic
reactions.
62

63. AGENTS THAT MODIFY FUNCTIONAL
GROUPS OF PROTEIN AND NUCLEIC
ACIDS :
OXIDIZING AGENTS :
 The most useful antimicrobial agents in this group are halogens
and hydrogen peroxide .
HALOGENS : IODINE
 It is used as a skin antiseptic and kills microorganisms by
oxidizing cell constituents and iodinating cell proteins.
1) Tincture of iodine:
 It is a preparation of iodine (2%) in a water-ethanol solution of
potassium iodide.
63

64. 2) IODOPHOR:
 It is prepared by complexing iodine with an organic carrier
such as povidone (forming povidine iodine).
 They are used as preoperative antiseptics as well as
disinfectants .
 Zuvendine, Wescodyne and Betadine.
64

65. Advantages Disadvantages
 Bactericidal,
mycobactericidal,
virucidal
 Not flammable
 Used for disinfecting
blood culture bottles
 Not sporicidal
 Requires prolonged
contact to kill fungi
 Stains surfaces
65

66. CHLORINE
 It is the most commonly available disinfectant.
 It may be available as - sodium hypochlorite
calcium hypochlorite (bleaching powder).
Uses
1) for municipal water supplies and swimming pool
2) as laboratory disinfectant
3) as bleaching agent to remove the stain from clothes.
Disadvantages
Organic matter interferes with its action, hence excess chlorine
always is added ensure microbial destruction
66

67. 2) HYPOCHLORITE :
 It is used in 0.5% -5% concentration for disinfection .
 It is most widely used for HIV infected material.
 be irritating at high concentrations
67

68. Advantages Disadvantages
• Bactericidal, tuberculocidal,
fungicidal, virucidal
• Sporicidal
• Fast-acting
• Inexpensive (in dilutable
form)
• Not flammable
• Unaffected by water
hardness
• Reduces biofilm on surfaces
• Relatively stable (eg, 50%
reduction in chlorine
concentration in 30 d)
• Reaction hazard with acids and
ammonias
• Leaves salt residue
• Corrosive to metals (some
ready-to-use products may be
formulated with corrosion
inhibitors)
• Unstable active (some ready-
to-use products may be
formulated with stabilizers to
achieve longer shelf life)
• Affected by organic matter
• Odor (some ready-to-use
products may be formulated
with odor inhibitors)
68

69. HYDROGEN PEROXIDE
 It is a strong oxidizer.
 Concentration:
3-6%, while catalase producing organisms and spores
require higher concentration (10%)
Uses
 It is used as high level disinfectant as well as chemical
sterilant .
 It is used to disinfect contact lenses, surgical prosthesis.
69

70. Advantages Disadvantages
 May enhance removal of
organic matter and
organisms
 No disposal issues
 No odor or irritation issues
 Does not coagulate blood
or fix tissues to surfaces
 Material compatibility
concerns (brass, zinc,
copper, nickel/silver
plating)
 Serious eye damage with
contact
70

71. ALKYLATING AGENTS
ALDEHYDES
 Formaldehyde and Glutaraldehyde.
FORMALDEHYDE:
 The formalin ( 40% formaldehyde) is the most widely
USES
1) preservation of anatomical specimen
2) formaldehyde gas is used for fumigation of closed areas, such
as operation theatres .
 Formaldehyde is toxic and irritant when inhaled, as well as it
is corrosive to metals.
71

72. GLUTARALDEHYDE:
 It is less toxic, less irritant and less corrosive
Uses
 It is best used to sterilize hospital and laboratory equipments,
such as endoscopes and cystoscopes.
 It is used as 2% concentration (2% Cidex).
 It usually disinfects objects within 20 minutes but may
require as long as 12hours to kill spores.
72

73. GASES
ETHYLENE OXIDE
 This is a colourless liquid with a boiling point of 10.7⁰C and
highly penetrating at normal temperature and pressure
Indications :
 It is used for sterilizing heat sensitive equipments like suture
materials dental equipment ,books and clothing.
 It has wide applications within and outside the hospital.
 It diffuses through many types of porous materials and readily
penetrates some plastics.
Contraindications
 It is unsuitable for fumigating rooms because of its explosive
property
73

74. LEVELS OF DISINFECTION
High level disinfectant: A chemical that kills all microbial
pathogens except large numbers of spores.
 Ex : glutaraldehyde and hydrogen peroxide.
Intermediate-level disinfectant : A chemical that kills all
microbial pathogens including mycobacteria and non-
enveloped viruses except spores.
 Ex : alcohol, phenolic compounds and iodophors.
Low-level disinfectant: A chemical that kills only vegetative
bacteria, fungi and enveloped viruses.
 Ex: quarternary ammonium compound.
74

75. SPAULDINGS CLASSIFICATION
75

76.  Critical items
76

77.  Semi critical items
77

78.  non critical items
78

79. STERILIZATION AND
DISINFECTION IN HEALTH CARE
SETTINGS :
79
STANDARD PRECAUTIONS :
CDC defines
Any standard of care designed to protect health care personnel
and patients from pathogens that can be spread by blood or any
other bodily fluids, excretion and secretion.
OSHA
NIOSH
ADA

80. cleaning of instruments
80

81. 81

82. Autoclaving and storage
82

83. Exposure control
 Surgical gowns
 Use of face mask
 Protective eye wear
 Hand care
 Gloving
83

84. 84

85. Face mask
We should touch
only the sides of
the mask when
we take it from
face mask box
85

86.  Protective eye wear
86

87. Hand care
87

88. 88

89. OCCUPATIONAL SAFETY AND HEALTH
ADMINISTRATION (OSHA)
89
OSHA GUIDELINES:
Employee OSHA training
Immunization programmes
Blood borne pathogen exposure
prevention and management
Aseptic rinses and cleaners
Personal protective equipment
Proper handling and disposal of medical waste

90. Guidelines for safe dental practice
during COVID-19 Pandemic
 Given by Ministry of Health and Family
Welfare, Govt of india.
 all dental professionals – vaccinated
90

91. RISK ASSESMENT
Low risk High risk
 Vaccinated
 No active symptoms
 RT- PCR negative
 COVID- 19 infected
after resolution of
symptoms – negative
All procedures can be
undertaken with
precautions
 Active symptoms
 RT-PCR positive
Only emergency procedures
– under standard protocol.
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92. Protocols to be followed
 one patient at a time, without attendant
if possible.
 screening of patients
 Use of face masks , hand hygiene and
physical distancing while in waiting area
92

93. Within the operatory
 spacing or barriers in multi- chair operatory
 Dental personnels within 2 meter of patient care –
should wear N-95 masks and surgical gowns or PPE
 Pre- procedural mouth washes
for reduction of viral load
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94. During procedure involving aerosol and splatter generating
procedures
 Use of face shield
 Use of high vaccum suction ( suction capacity – 6.6 litres/
minute )
 Use of rubber dam – whenever possible.
After procedure
 soiled gowns and gloves should be removed as soon as
possible.
 Proper handwashing – Avoid use of towels , paper towels are
preferred
 Procedure and prescription writing should be recorded – after
doffing of ppe.
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95. Disinfection of dental clinic
• It should be done after patient leaves the treatment room
• Hand instruments - sterilization
• Water outlets – flushed for 30 – 40 sec
air way syringes disinfected with
hand pieces 1 %hypochlorite
Water containers
• Dental chair & auxillary parts-disinfected ( 1% hypochlorite )
• Floors – 2 step procedure .
95

96.  CONCLUSION
Increases in serious transmissible diseases over the last few
decades have created global concern and impacted the
treatment mode of all health care practitioners. Emphasis
has now expanded to assuring and demonstrating to patients
that they are well protected from risks of infectious disease.
Infection control has helped to allay concerns of the health
care personnel and instill confidence and in providing a safe
environment for both patient and personnel.
96

97. REFERENCES:
 1)Sastry AS. Essentials of medical microbiology. 1st ed. New Delhi : Jaypee
brothers; 2016. p 30-42
 2)Ananthanarayan R, Paniker CKJ. Ananthanarayan and panikers text book of
microbiology . 10th ed.Telangana: Universities press; 2017.
 3)Bhaveja CP. Text book of Microbiology for dental students. 5th ed. New delhi:
Arya; 2015. p21-29
 4) Peter S. Essentials of Public health dentistry. 6th ed. New delhi: Arya medi;
2017. p 70-81
 5) Hiremath SS. Textbook of Preventive and Community Dentistry .2nd ed. New
delhi: Elsevier; 2011.
 6) Laskin DM. Oral and Maxillofacial Surgery. 1st ed. New delhi: Aitbs ; 2013.p
347-348
 7) Rutala WA, Weber DJ . Disinfection, sterilization and antisepsis : an overview .
Am J Infect Control.2016;44(5):e1-6
 8)Thomas MV, Jarboe G, Frazer RQ. Infection control in dental office .Dent Clin
North Am.2008;252(3):608-28
 9) Boyce R ,Mull J. Complying with occupational safety and health administration
: guidelines for dental office . Dent Clin North Am.2008:52(3):653-68
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