4. Contents:
Introduction.
Terminologies.
Objectives.
Modes of transmission in Dental clinic.
General Principles of Infection Control.
OSHA Regulations to Prevent Infection.
Various Methods and Sterilization Technique.
Sterilization Control.
Clinical Aspects.
Conclusion.
Bibliography.
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5. Introduction:
Concept of asepsis and its role in prevention of infection - two
decades back.
1850- Ignaz Semmelweiss & Oliver Holmes - general principles.
Principles accepted after - Joseph Lister’s studies (1865-1891).
Infection Control procedures - well recognized in General Surgery
and General Medicine.
Were late to come in dentistry.
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6. Terminologies:
INFECTION CONTROL :
Also called “exposure control plan” by OSHA is a required office
program that is designed to protect personnel against risks of
exposure to infection.
STERILIZATION :
Use of a physical or chemical procedure to destroy all
microorganisms including substantial numbers of resistant
bacterial spores.
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7. Contd..
DISINFECTION:
It is a process of destruction of vegetative forms of pathogenic
organisms which are capable of producing infection but not necessarily
resistant to spores.
ASEPSIS:
Prevention of microbial contamination of living tissues or sterile
materials by excluding, removing or killing microorgnisms.
S.G.Damle Textbook of Pediatric Dentistry, Fifth Edition, Arya Medi Publishing House Pvt Ltd.
7
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8. Contd..
BACTERIOSTATIC AGENTS:
Chemical agents that inhibit bacterial growth.
BACTERIOCIDAL AGENTS:
Substances that are able to kill bacteria.
ANANTHANARAYAN AND PANIKER’S TEXT BOOK OF MICROBIOLOGY,7TH EDITION ,UNIVERSITY PRESS,HYDRABAD 2008
8
8-Mar-18
9. Objectives:
Elimination or reduction in all types of microorganisms.
Breaking the cycle of infection and eliminating cross
contamination.
For the protection of the dentist , patients and for all the
members of the dental team.
Ensuring and showing confidence to patients that they are well
protected from risk of infectious disease.
SOBEN PETER,ESSENTIAL OF PREVENTIVE AND COMMUNITY DENTISTRY,3RD EDITION,ARYA
PUBLISHER,NEW DELHI,2014
9
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11. Modes of Infection Transmission in Dental
Clinic:11
MODES
Direct
Indirect
Droplet
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12. Contd..
1) Direct: From an infected person to the one who is not immune.
• Contact – cross infection, saliva and blood.
2) Indirect: From contact with objects that are contaminated.
• Contact - a) Light handle
b) Three way syringe
c) Aerotor
d) Suction tip handle
e) Enamel tray
f) Mobile phones
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13. Contd..
3) Droplet: From spray or splatter contact with mucous membrane
or contact with aerosols.
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15. Cross Infection:
Cross-infection is defined as the transmission of infectious
agents among patients and staff (clinical and non-clinical staff)
within a clinical environment.
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17. General Principles of Infection Control:
Identifying high-risk patients and source of infection.
Universal protection.
Prevent environmental contamination.
Use of sharp instruments & needles.
Handling biopsy specimen.
Prosthodontic consideration.
Infection control during radiography.
Biomedical waste.
Miscellaneous.
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18. 1. Identifying high-risk patients and source of
infection:-
Understanding the disease and their root of transmission that has high susceptibility.
Screening of every new patient - medical history and oral examination.
Update patient’s medical history.
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19. 2. Universal protection:-
It is recommended that certain basis infection control procedure must be
followed routinely for all patients, referred to as Universal Protection.
Universal protection for dental team-
a) Hand washing
b) Protection barrier technique
c) Immunization
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22. (b) Protection barrier technique:-
To reduce the risk of transmission of infectious agents, PPE must be used appropriately.
The outlines sequences and procedures for putting on and removing PPE (Personal
Protective Equipments).
Infection prevention and control is integral to clinical care and the way in which it is
provided. It is not an additional set of practices.
If effectively implemented, the two-tiered approach of standard and transmission-based
precautions recommended in these guidelines provides high-level protection to
patients, healthcare workers and other people in healthcare settings.
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23. Sequence of putting PPE-
Hand hygiene must be performed before putting on PPE and after removing
1) GOWN
• Fully cover torso from neck to knees, arms to end of wrists, and wrap around the
back.
• Fasten at the back of neck and waist.
2) MASK
• Secure ties or elastic bands at middle of head and neck.
3) PROTECTIVE EYEWEAR OR FACE SHIELD
• Place over face and eyes and adjust to fit
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25. SEQUENCE FOR REMOVING PPE-
REMOVE PPE AT DOORWAY OR IN ANTEROOM
1) GLOVES
• Outside of gloves is contaminated!
• Grasp outside of glove with opposite gloved hand; peel off.
• Hold removed glove in gloved hand.
• Slide fingers of ungloved hand under remaining glove at wrist.
• Peel glove off over first glove.
• Discard gloves in waste container.
PERFORM HAND HYGIENE
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26. 2) PROTECTIVE EYEWEAR OR FACE SHIELD
• Outside of eye protection or face shield is contaminated!
• To remove, handle by head band or ear pieces.
• Place in designated receptacle for reprocessing or in waste container.
3) GOWN
• Gown front and sleeves are contaminated!
• Unfasten ties.
• Pull away from neck and shoulders, touching inside of gown only.
• Turn gown inside out.
• Fold or roll into a bundle and discard.
4) MASK
• Front of mask is contaminated — DO NOT TOUCH!
• Grasp bottom, then top ties or elastics and remove
• Discard in waste container
PERFORM HAND HYGIENE IMMEDIATELY AFTER REMOVING ALL PPE
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27. Types of Gloves
Based on application
Patient
Examination
Gloves
Surgical
Gloves
Non-surgical
Gloves
27
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28. Contd..
Based on material used
LATEX GLOVES
• Have a high level of
touch sensitivity.
• Can be worn for
extended period of time.
• lightly powdered, making
it easier to put on.
• very elastic.
• Cost effective.
NITRILE GLOVES
• Latex-free.
• Are most puncture
resistant.
• Mold to your hand for a
great fit.
• Work well for high-risk
situations.
• Have a long shelf life.
VINYL GLOVES
• Latex-free.
• looser fit.
• Good for short-term, low-
risk tasks.
• Most economic.
• Best for use with non-
hazardous materials.
• lightly powdered to make
it easier to put on.
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31. Types of Face Mask
31
Disposable Mask Reusable Mask
N95 Respirator Mask
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32. (c) Immunization:-
Vaccines Recommendations in brief
Hepatitis B Get the 3-dose series (dose #1 now, #2 in 1 month, #3
approximately 5 months after #2).
Flu (Influenza) Get 1 dose of influenza vaccine annually.
MMR (Measles, Mumps, & Rubella) only 1 dose of MMR is recommended.
Varicella (Chickenpox) If you have not had chickenpox (varicella), get 2 doses
of varicella vaccine, 4 weeks apart.
Tdap (Tetanus, Diphtheria, Pertussis) Get a one-time dose of Tdap as soon as possible if you
have not received Tdap previously (regardless of when
previous dose of Td was received).
Get Td boosters every 10 years
Meningococcal Those who are routinely exposed to isolates of N.
meningitis should get one dose.
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33. 3. Prevent environmental contamination:-
The waste products carries a higher potential for infection and injury than any
other type of waste.
Therefore, it is essential to have safe and reliable method for its handling.
Inadequate and inappropriate handling of health-care waste may have
significant impact on the environment.
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34. 4. Use of sharp instruments & needles
Sharp items (e.g., needles, scalpel blades, wires) contaminated with patient
blood and saliva - potentially infective.
Used needles should never be recapped or otherwise manipulated utilizing
both hands, or any other technique that involves directing the point of a
needle toward any part of the body.
Either a one-handed "scoop" technique or a mechanical device designed for
holding the needle sheath should be employed.
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35. 5. Handling biopsy specimen:-
In general, each biopsy specimen should be put in a sturdy container with a
secure lid to prevent leaking during transport.
Care should be taken when collecting specimens to avoid contamination of
the outside of the container.
If the outside of the container is visibly contaminated, it should be cleaned
and disinfected or placed in an impervious bag.
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37. 7. Infection control during radiography:-
Precautions to be taken before taking the radiograph:
• Gloves must be worn when taking radiographs and handling contaminated film
packets.
• Powder- free gloves are recommended as powder can affect the film's emulsion
layer and cause image artifacts.
• Touch as few surfaces as possible.
Precautions to be taken while taking the radiograph:
• Use foot controls for chair adjustment and film exposure.
• Touch as few surfaces as possible.
• Remove the lead apron with clean, ungloved hands to avoid contamination.
• Place unused films on a tray or paper towel.
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38. Precautions after taking the radiograph:
• Leave reusable instruments in the treatment room and clean them according
to standard office procedures.
• Wipe the film packet dry.
• Gloves and other PPE can then be removed and hands washed.
Infection control precautions for processing the film:
• Care should be taken when unwrapping films to avoid contamination of the
developing equipment and surrounding environmental surfaces.
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39. 8. Biomedical waste:-
Management of Hazardous waste in Dental Operatory:
1) Mercury containing waste
• Contact a Certified biomedical Waste Carrier (CWC) for disposal and recycling.
• Use a ‘mercury spill kit’ in case of spill of mercury.
2) Silver containing waste
• Should not be rinsed down in drain.
• The waste should be handed offer to CWC.
3) Lead containing waste
• Should be handed over to CWC.
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40. 4) Blood-soaked gauze
• Should be disposed in yellow biomedical waste bag covered with a double bag, labelled
with biohazard symbol.
5) Sharps
• Should be disposed in white/blue puncture-resistant biomedical waste bag.
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41. OSHA (Occupation Safety and Health Administration)
Regulations to Prevent Infection:
Establish an exposure control plan.
Employers must update the plan annually.
Implement the use of universal precautions.
Identify and use engineering controls.
Identify and ensure the use of work practice controls.
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42. Provide personal protective equipment (PPE) such as gloves, gowns, eye
protection.
Hepatitis B vaccinations to all.
Post-exposure evaluation and follow-up to any occupationally exposed
worker.
Use labels and signs to communicate hazards.
Maintain worker medical and training records.
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44. 1. Operating Area:
Plastics are used to cover the chair and unit.
Changes the bag after each patient.
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45. 2. Surface Disinfection:
Used for mechanical removal of organic debris.
Spray – Wipe – Spray Technique.
Use 4 x 4 Gauze to wipe the surfaces in overlapping strokes.
Recommended surface disinfectants are:-
A. Sodium hypochlorite
B. Iodophors
C. Phenol
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49. Definition:
Sterilization refers use of a physical or chemical procedure to destroy all
microorganisms including substantial numbers of resistant bacterial spores.
Instruments that have undergone sterilization can be maintained in such
condition by containment in sealed packaging until use.
49
8-Mar-18ANANTHANARAYAN AND PANIKER’S TEXT BOOK OF MICROBIOLOGY,7TH EDITION,2005,UNIVERSITY PRESS 2005.
50. General Principles of Sterilization:
All used instrument should be thoroughly cleaned.
The modes of sterilization should be in contact with every
surface of each instrument.
All sterilizing equipment must be regularly serviced and
maintained.
Follow the manufacturer’s instruction.
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53. Red Heat:
Materials are held in the flame of a Bunsen burner till they become red hot.
Uses:
Inoculating wires or loops
Tips of forceps
Surface of searing spatula
Needles
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54. Flaming:
Materials are passed through the flame of bunsen burner without allowing
them to become red hot.
Uses:
Glass slides
Scalpels
Mouths of culture tubes and bottles
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55. Incineration:
Incineration is a waste treatment process that involves the combustion of organic
substances contained in waste materials.
Used to sterilize medical and other biohazardous waste before it is discarded with
non-hazardous waste.
55
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56. Hot Air Oven:
The destruction of microorganisms through the use of dry heat is a gradual
phenomenon.
With longer exposure to lethal temperatures, the number of killed
microorganisms increases.
The standard setting for a hot air oven is at least two hours at 160 °C for 2
hours.
A rapid method heats air to 190 °C for 6 minutes for unwrapped objects and
12 minutes for wrapped objects.
Temperature above 180 °C is not recommended for wrapped objects as it may char
the wrapping.
56
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57. Contd..
Uses:
Glassware like glass syringes, swabs, petri dishes,
pipettes and test tubes.
Surgical instruments like scalpels, scissors, forceps etc.
Chemicals like liquid paraffin, fats and grease etc.
57
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58. Contd..
Dry heat has the advantage that it can be used on powders and other
heat-stable items that are adversely affected by steam (e.g. it does not
cause rusting of steel objects).
58
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59. Placing instruments inside hot air oven:
Arrange instruments such that it allows the free circulation of air between
instruments.
Glassware should be perfectly dried.
Cutting instruments ideally sterilised at 150 °C for 2 hours.
Ove must be allowed to cool slowly for about 2 hours, before the door is
opened.
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60. Glass Bead Sterilizers:
Glass bead sterilizers work by heating glass beads to 250 °C.
Instruments are then quickly doused in these glass beads, which heat the
object while physically scraping contaminants off their surface.
Once a common sterilization method employed in dental offices.
Not approved by the U.S. Food and Drug Administration (FDA) and Centers for
Disease Control and Prevention (CDC) to be used as a sterilizers since 1997.
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63. Tyndallisation:
A more effective method is Tyndallisation, which uses three successive steam
treatments to achieve sterilization over the course of three days.
Works by killing vegetative cells, allowing germination of surviving spores, and
killing the resulting vegetative cells before they have time to form further
spores.
Any surviving spores from the first treatment, or incidentally formed spores
during the first incubation period, are killed in a third steaming cycle.
Uses:
For sterilization of egg, serum or sugar containing media.
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64. Water Bath:
Serum or body fluids containing coagulable proteins can be
sterilized
By heating for 1 hour at 560C.
64
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65. Autoclave:
Autoclave is a device that uses steam to sterilize equipment and other
objects.
This means that all bacteria, viruses, fungi, and spores are inactivated.
In dentistry, autoclaves provide sterilization of dental instruments, once
sterilized using a vacuum autoclave instruments can be kept for up to 12
months using sealed pouches.
3 types of Autoclave:
a) simple iron jacket
b) low pressure low temperature
c) high pressure high vacuum
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66. Principle of Autoclave:
• Boiling point of water is directly proportional to the pressure when volume is
constant.
• When pressure is increased in a closed vessel, temperature increases
proportionally.
• Pressure and temperature is kept constant for 20 minutes.
• Sufficient to kill all vegetative forms and spore forms of bacteria.
Temperature = 121 °C
Pressure = 15 psi
Time = 15-20 mins
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68. Precautions to use autoclave:
1. All the air must be removed from the autoclave chamber.
The admixture of air with steam results in low temperature being
achieved.
The air being denser forms a cooler layer in the lower part of the
autoclave.
2. Materials should be arranged in such a manner which ensures free
circulation of steam inside the chamber.
3. Lid should not open until inside pressure reaches to the atmospheric
pressure.
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69. Sterilization Control:
Browne's tubes:-
Are glass tubes that contain heat sensitive dyes. These change colour after
sufficient time at the desired temperature.
Before heat exposure, contents appear red.
As heating progresses, color changes to green.
Only when the tube is green, sterilization conditions can be considered
adequate.
69
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70. Contd..
Autoclave tape:-
• Tape printed with sensitive ink that undergoes color change at a specific
temperature.
• Two pieces of tape are struck on a piece of square paper.
• At 134 °C temperature for 3.5 minutes, uniform bar develops on the
entire length of strip.
• This shows that stean has passed freely and rapidly at the centre of the
load.
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73. Non-Ionizing Radiation Sterilization:
Ultraviolet light irradiation (UV, from a germicidal lamp) is useful for
sterilization of surfaces and some transparent objects.
The wavelength of UV radiation ranges from 328 nm to 210 nm. Its maximum
bactericidal effect occurs at 240–280 nm.
UV irradiation is routinely used to sterilize the interiors of biological safety
cabinets between uses.
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74. Ionizing Radiation Sterilization:
Gamma radiation is very penetrating, and is commonly used for sterilization
of disposable medical equipment, such as syringes, needles, cannulas and IV
sets.
It is emitted by a radioisotope, usually Cobalt-60(60Co) or caesium-137(137Cs),
which have photon energies of up to 1.3 and 0.66 MeV respectively.
Use of a radioisotope requires shielding for the safety of the operators while
in use and in storage.
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76. Heating provides a reliable way to rid objects of all transmissible agents, but
it is not always appropriate if it will damage heat-sensitive materials such as
biological materials, fibre optics, electronics, and many plastics.
In these situations chemicals, either as gases or in liquid form, can be used
as sterilants.
use of chemical sterilants poses new challenges for workplace safety, as the
properties that make chemicals effective sterilants usually make them
harmful to humans.
76
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77. Ethylene Dioxide:
Ethylene oxide (EO, ETO) gas treatment is one of the common methods
used to sterilize, pasteurize, or disinfect items because of its wide range of
material compatibility.
Treatment is generally carried out –
Temperature - 30 °C and 60 °C
Relative humidity - above 30%
Gas concentration - 200 and 800 mg/l
It penetrates all porous materials, and it can penetrate through some
plastic materials and films.
The most common ethylene oxide processing method is the gas chamber method.
77
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78. Contd..
There are 3 phases in ETO sterilization:
a) Preconditioning
b) Sterilization
c) Aeration
Cycle time is usually more than 14 hours.
78
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79. Ozone:
Ozone is used in industrial settings to sterilize water and air, as well as a disinfectant
for surfaces.
Ozone is a very efficient sterilant because of its strong oxidizing properties capable
of destroying a wide range of pathogens, including prions without the need for
handling hazardous chemicals.
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80. Glutaraldehyde & Formaldehyde:
These are accepted liquid sterilizing agents, provided that the immersion time
is sufficiently long.
To kill all spores in a clear liquid can take up to 22 hours with glutaraldehyde
and even longer with formaldehyde.
Both are volatile, and toxic by both skin contact and inhalation.
Many vaccines, such as the original Salk polio vaccine, are sterilized with
formaldehyde.
2% conc. Of Glutaraldehyde - disinfection – 20 min.
sterilization – 6-10 hrs.
80
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81. Contd..
Formaldehyde Gas:
• Employed for fumigation of operating & other rooms.
• Gas is generated by adding 150g of KMnO4 to 280ml of formalin for every
1000cu.ft
• Considerable heat and vapors generated
• Doors kept close for 48 hours.
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82. Iododphors:
Used for surgical scrub and surface antisepsis.
Usually effective within 5-10 minutes.
Undesirable properties are corrosiveness, staining, irritation of tissues, and
allergic.
Broad-spectrum antimicrobial activity.
Povidone-iodine is much more stable.
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83. Chloroxylenol:
Broad spectrum antimicrobial chemical compound used to control bacteria,
fungi and viruses.
Non-corrosive, non irritant.
4.8% Chloroxylenol + 9% Terpinol + 13% alcohol = DETTOL
83
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85. 1. Sharp Instruments & Needles:
Should be disposed in proper containers.
Avoid keeping uncapped needles in instrument trays or operating area.
Always cap needles by ‘scoop method.’
85
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86. Miscellaneous:
Instrument/Material Disinfection/Sterilization Method
1. Hand piece • Clean and sterilize/ disinfect after
each patients.
• Discharge air & water for 20-30 sec.
• Flush 20-30 sec air/water lines in
hose before attaching.
2. Casts • Chlorine compound or Iodophor.
3. Alginate Impression • Chlorine compound or Iodophor,
2% Glutaraldehyde.
4. Impression compound • Chlorine compound or Iodophor.
86
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87. Contd..
Instrument/Material Disinfection/Sterilization Method
5. Removable appliances • Chlorine compound or iodophor.
6. Stainless Steel Crown • Hydrochloric acid
7. Burs • Dry heat sterilization or use
disinfectant.
8. Radiograph • Film holder, bite block can be used.
• Plastic cover for sensor.
9. Gutta Percha Point • 2.5 % aqueous sodium hypoclorite
solution .
87
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88. Contd..
Instrument/Material Disinfection/Sterilization Method
10. Paper point • Gamma radiation [ cobalt 60 ].
11. Files • Autoclave or lasers [co2 ].
12. Rubber mouth props • Steam autoclave, chemiclaved upto
127⁰ C.
13. Patient drape • Dry sterilization.
14. Sutures • Autoclave.
15. Swabs • Autoclave (Gamma radiation, hot air
oven).
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90. Conclusion:
Sterilization and Disinfection are costly and time consuming process.
However, it is essential in all health care facilities to avoid infection.
It depends on the material and use of instrument.
Operator should keep in mind that contaminated instrument present risk
to the patient as well as the user himself.
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91. 91
Title Knowledge, Attitudes, and Practice Regarding Infection
Measures Among Dental Students in Central India
Author Abhinav Singh, Bharathi M. Purohit, Ajay Bhambal, Sudhanshu
Saxena, Anshika Singh, and Amrita Gupta,
Journal Journal of Dental Education
Aim To determine the level of knowledge, attitudes, and practice
regarding infection control measures and if any correlation
among the knowledge, attitudes, and practice scores.
Material & Method A questionnaire study was conducted among dental students
(third year, final year, interns) of People’s College of Dental
Sciences, Bhopal city, Central India. The sample comprised of
eighty-six third-year dental students, eighty-two final-year
students, and seventy-seven interns.
8-Mar-18
92. 92
Result Of the 245 dental students, 63 were males and
182 females. No significant differences were
noted between males and females. Only 39.2
percent of the undergraduates used antiseptic
solution to wash their hands before and after
patient examination. The majority (92.2
of the students considered isolation to be an
important infection control measure.
61.2 percent of the undergraduate dental
students had not been vaccinated with
vaccine.
Conclusion The most surprising result of the study was that
61.2 percent of the undergraduate dental
students had not been vaccinated with
vaccine. The Dental Council of India has made
hepatitis B vaccination mandatory for dental
students prior to admission, although the
has not listed it as a requirement.
8-Mar-18
93. Bibliography:
S.G.Damle Textbook of Pediatric Dentistry, Fifth Edition, Arya Medi Publishing House Pvt Ltd.
ANANTHANARAYAN AND PANIKER’S TEXT BOOK OF MICROBIOLOGY,7TH
EDITION,2005,UNIVERSITY PRESS 2005.
NEELIMA ANIL MALIK.,TEXTBOOK OF ORAL AND MAXILLOFACIAL SURGERY ,SECOND
EDITION,J P BROTHERS,2010
MCDONALD,AVERY DEAN,DENTISTRY FOR THE CHILD AND ADOLESCENT,8TH
EDITION,ELISVIER,NEW DELHI,2004
SOBEN PETER.,ESSENTIAL OF PREVENTIVE AND COMMUNITY DENTISTRY ,4TH
EDITION,ARYA(MEDI)PUBLISHING HOUSE,NEW DELHI,JULY2008.
RAJESH BHATIA, RL ICHHPUJANI. MICROBIOLODY FOR DENTAL STUDENTS. JAYPEE
BROTHERS, 3RD EDITION, 2003.
93
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94. WILLIAM A. RUTALA, GUIDELINE FOR DISINFECTION AND STERILIZATION IN
HEALTHCARE FACILITIES, 2008
SHARON K. DICKINSON, RICHARD D. BEBERMEYER. GUIDELINES FOR INFECTION
CONTROL IN DENTAL HEALTH CARE SETTINGS,2008 VOL 20,NO 10.
NIKHIL MARWAH,TEXT BOOK OF PEDIATRIC DENTISTRY,THIRD EDITION,NEW
DELHI,2014
ANN N. DO, CAROL A. CIESIELSKI , RUSS P. METLER , TERESA A. HAMMETT ,JIANMIN
LI,PATRICIA L. FLEMING , PHD JOURNAL OFINFECTION CONTROL AND HOSPITAL
EPIDEMIOLOG VOL. 24, NO. 2 (FEBRUARY2003) (PP. 86-96)
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