Infection control in dentistry is important to prevent transmission between patients and dental health care workers. Proper procedures include standard precautions like hand hygiene, protective barriers, and sterilization of instruments. Airborne pathogens can spread through aerosols from handpieces, so high-volume evacuation and masks are used. Exposure risks include contamination of surfaces and cross-infection, so aseptic protocols are followed. Immunization of dental workers against diseases like hepatitis B and influenza helps control infections. High-risk patients require additional precautions with barriers and care of instruments.

1. Infection control in Conservative
Dentistry & Endodontics
By,
Dr.Basavan Gowda
Reader
Navodaya dental college
Raichur

2. Definitions:
• Sterilization: Process by which an articles, surface or medium is freed of
all microorganism either in vegetative or spore form.
• Disinfection : Process which reduces the number of viable microorganism
to an acceptable level but may not inactivate some virus and bacterial
spores.
• Antiseptic : Chemical which can be safely applied to skin or mucus
membrane surfaces and used for preventing infection by inhibiting growth
of bacteria.
• Cross infection control :Is the sum total of all the measures taken to
prevent subsequent infection.

3. Why is Infection Control Important in Dentistry?
• Both patients and dental health care personnel (DHCP) can be exposed to
pathogens
• Contact with blood, oral and respiratory secretions, and contaminated
equipment occurs
• Proper procedures can prevent transmission of infections among patients
and DHCP
Modes of Transmission
• Direct contact with blood or body fluids
• Indirect contact with a contaminated instrument or surface
• Contact of mucosa of the eyes, nose, or mouth with droplets or spatter
• Inhalation of airborne microorganisms
DCNA 2003;691-708

4. Chain of infection
• All links must be connected for infection to take place
Pathogen
Source
Mode
Entry
Susceptible Host

5. Factors or determinants of an infectious disease
• The interaction determines the outcome of an infection as follows
Health or Disease = Virulence X Dose
Body Resistance
• Health is favoured by decrease in virulence & dose of microrganisms.
• Disease is favored by increase in virulence & dose of micro. & decrease in
resistance.
Approach to infection control
• Reducing dose of microorganisms that might be shared between patients &
dental team.
• Increasing resistance of dental team by immunization against specific
infections.

6. Exposure risks in dental operatory
A) Airborne contamination
B) Hand-to-surface contamination
C) Cross infection
D) Patient vulnerability
E) Personnel vulnerability
A)Airborne contamination
• Ahigh speed handpiece is capable of creating airborne contaminants.
• It exist in the form of aerosols, mists, and spatter

7. Aerosols are invisible particles ranging from 5- 50 microns.
• Remain suspended in air for hours
• Can carry any respiratory pathogens to the lungs.
J Dent Rest 48;49-56,1969
• Study used water-soluble red-fluorescent poster paint (plain water-soluble
fluorescent-red tempera in water) as a visible substitute for saliva to elevate
awareness and facilitate problem solving in infection control
J Am Dent Assoc 96:801–804, 1978

8. Mists are droplets approaching 50microns or more
• Tend to settle gradually from air after 5-15 min
J Am Dent Assoc 125;579-84;1994
• Both aerosols and mists produced by cough of patient with unrecognized
active pulmonary or Pharyngeal tuberculosis are likely to transmit the
infection.
Spatter are particles larger than 50 microns and are visible.
• They have a distinct trajectory, usually falling within 3 feet of patient
mouth.
• Spatter has a potential of causing infection of dental personnel by blood
borne pathogens.
Morbid Mortal Wkly Rep 38;5-6,1989

9. B) Hand-to-surface-contamination
• With saliva contaminated hands, the dentist could repeatedly contact or
handle unprotected Operatory surfaces during treatment if not careful.
• Amalgamator, light curing devices, camera equipments are also subject to
heavy contamination by soiled hands.
• Mobile phones may also act as an important source of nosocomial
pathogens in the dental setting
J Dent Educ .2010 Oct;74(10):1153-8
• Contamination free maintenance of these items is a priority objective today.

10. C) Cross infection
• “The transmission of infectious agents between patients and staff within a
clinical environment”
• Transmission may result from person to person contact or via contaminated
objects.
• Patient-to-patient transmission of hepatitis B virus (HBV) - transmission
of a blood borne pathogen in a dental setting in the United States.
The Journal of Infectious Diseases 2007; 195:1311–4
• The major route of cross infection in Conservative Dentistry and
Endodontics is via infection through intact skin or mucosa due to accidents
involving sharps, or direct inoculation onto cuts and abrasions in the skin.

11. D) Patient vulnerability
• Although infection risks for dental patients have not been as well
investigated as those of hospital patients, they appear to be low.
• Nine cluster cases of dentist-to-patient transmission of HB and one cluster
case of HIV has been well documented since 1971.
• In 1999, a group of six patients was found to be with same strain of HIV
virus that infected the Florida dentist who treated them.
Surveillance Report 10;26;1998
E) Personnel vulnerability
• When dental personnel experience exposure of saliva, blood, and possible
injury from sharp instrumentation while treating patients, they are more
vulnerable to infections if they have not had proper immunizations or used
the protective barriers.
J Am dent assoc 110;629-33;1985

12. Infection control program
• To reflect new data, materials, technology, and equipment.
When implemented.
• Types of infection control program
• 1. IC program by center for disease control and prevention
• 2. IC program byADA(American DentalAssociation)
• 3. IC program by Federal Occupational Safety and Health
Agency (OSHA)

13. Exposure Control Plan by OSHA
• Use of Universal Precautions
• Required use of personal protective equipment
• Standardized housekeeping
• Laundering of contaminated protective clothing
• Policy on general waste disposal
• Labeling procedure
• Policy on sterilization (including monitoring) and disinfection
• Standardized handwashing protocol
• Hepatitis B virus (HBV) vaccination
• Postexposure evaluation and medical follow-up

14. Standard Precautions
• Wash hands before and after every patient.
• Wear gloves when touching blood, body fluids, secretions, and
contaminated items.
• Use care when handling sharps.
• Wear a mask and eye protection, or a face shield.
• Carefully handle contaminated patient care items to prevent the transfer of
microorganisms to people or equipment.
• Use a mouthpiece or another ventilation device as an alternative to mouth-
to-mouth resuscitation when practical.
• Standard Precautions must be used in the treatment of all patients.

15. Hand Hygiene
• Wash hands before putting on gloves and
immediately after removal
• At beginning of treatment period - jewelry,
and rings should be removed
• long fingernails can harbour pathogens,
nails should be kept short.
• Treatment room sinks be equipped with
“hands-free” faucets that are activated
electronically or with foot pedals

16. • use liquid soap as bar soap may transmit contamination
• Waterless antiseptic agents are alcohol based products that are available in gels,
foams, or rinses.
• Hand cleansers containing a mild antiseptic like 3% PCMX (parachlorometa-
xylenole) or chlorhexidine - preferred to control transient pathogens and to
suppress overgrowth of skin bacteria
Infect Control Hosp Epidemiol 12;654-62;1991
• 4% chlorhexidine – broader activity but hazardous to eyes
J Am Dent Assoc 99;65-7;1979
Am J Ophthalmol 104;50-56;1987

19. Personal Protective Equipment
• Protective clothing
• Protective eyewear
• Surgical mask
• Gloves

20. Protective Clothing Requirements
• should be made of fluid-resistant material.
• To minimize the amount of uncovered skin, clothing should have long
sleeves and a high neckline.
• Buttons, trim, zippers, and other ornamentation (may harbour pathogens)
should be kept to a minimum.
Guidelines for the Use of Protective Clothing
• not worn out of the office for any reason
• Protective clothing should be changed at least daily and more often if
visibly soiled.
• If a protective garment becomes visibly soiled or saturated with chemicals
or body fluids, it should be changed immediately.
• Hot water (70 -158 F) or Cool water containing 50 to 150 ppm of
chlorine can be used- to provide more antimicrobial action
Garner JS, Favoero MS ; 1985; Center for Disease control

21. Protective Masks
• Worn over the nose and mouth to protect from inhaling infectious
organisms
• A mask with at least 95 percent filtration efficiency for particles 3 to 5
micrometers (μm) in diameter should be worn whenever splash or spatter is
likely
• Recommendations for changing mask – after 20 min in aerosol & 60 min
in non-aerosol environment
• When not in use, it should never be worn below the nose or on the chin.
• Two most common types of masks are the domeshaped and flat types

22. • Average surgical mask does not protect one from the influx of very small
virus particles in the air
• National Institute for Occupational Safety and Health (NIOSH) and the
Centers for Disease Control and Prevention (CDC) recommend the use of a
NIOSH-certified N95 for the protection of healthcare workers who come in
direct contact with patients with H1N1

24. Protective Eyewear
• Worn to protect the eyes against damage
from aerosolized pathogens
• Eyewear must be optically clear, anti-
fog, distortion-free, close-fitting and
should be shielded at the sides
• BBP Standard requires the use of
eyewear with both front and side
protection during exposure prone
procedures

25. Face Shields
• Chin-length plastic face shield may be
worn as an alternative to protective
eyewear.
• Shield cannot replace face mask
because it does not protect against
inhalation of contaminated aerosols

26. Gloves
• Medical grade nonsterile examination gloves and sterile surgical gloves are
medical devices that are regulated by the U.S. Food and Drug
Administration (FDA).
• Different types of gloves are used in a dental office
Examination
Gloves/ surgical
gloves
Overgloves Utility Gloves
Non–Latex-
Containing Gloves

27. Guidelines for the Use of Gloves
• Single use.
• May not be washed, disinfected, or sterilized.
• Gloves DO NOT replace the need for hand hygiene.
• Wash hands before donning gloves and upon glove removal
• Open new fresh gloves just before starting procedure
• Replace torn or damaged gloves immediately.
• Do not wear jewellery under gloves
• Remove contaminated gloves before leaving the chair side during patient
care, and replace them with new gloves before returning to patient care

28. How to wear gloves
How to remove gloves

29. Maintaining Infection control while gloved
• Anticipate required materials and have those items ready and easily
accessible for each procedure to save time and minimize cross-
contamination
• When opening a container use overgloves, a paper towel, or a sterile gauze
sponge . In doing this, take care not to touch any surface of the container.
• Use sterile cotton pliers to remove an item from the container

30. Managing Contaminated Sharps
• Contaminated needles and other disposable sharps must be placed into a
sharps container.
• The sharps container must be puncture-resistant, closable, leakproof, and
color-coded
• Sharps containers must be located as close as possible
• Always use the single-handed scoop technique or some type of safety
device

31. Hospital waste categories and disposal

33. Mercury Spill Kits
• MERCURY MAGNETTM powder is the remedy for proper decontamination and
clean up of a mercury spill area.
• Concentrations of mercury vapor greater than 0.1mg/m3 exceed the OSHA
permissible exposure limit. Concentrations of up to 20mg/m3 can go unnoticed
for long periods of time, creating a serious hazard to health.
• The powder reacts with liquid mercury to form a solidified amalgam, which not
only brings the mercury vapor pressure below harmful levels, but also allows easy
pick up using a common magnet

34. • Selenium acts as a mercury magnet with a very strong binding affinity for
the toxic substance.
• This strong attraction allows selenium to mix and neutralize their reaction
characteristics.
• This new Hg - Se substance that is produced is not absorbed by the body
and gets flushed out of the system.
• This is a very beneficial interaction that removes mercury from the body
before it can lodge in fatty tissue and cause damage.
http://www.naturalnews.com/030130_selenium_mercury.html#ixzz36ymWq
we7

35. Operatory Asepsis
• Design of the premises and the layout of the dental surgery and treatment
areas are important factors in implementing successful infection control
• Dental operatory and the instrument reprocessing rooms must have clearly
defined clean and contaminated zones
• Floor coverings in the dental operatory must be non-slip and impervious
with sealed joints
• Computer keyboards should be covered where possible in treatment areas,
and cleaned regularly in non-treatment areas.
• A number of keyboards are available that have flat surfaces and can be
wiped over with detergent or with alcohol-impregnated wipes between
patient appointments.

36. Materials impervious to moisture that are used to prevent contamination of
surfaces.
▫ Plastic sheets
▫ Impervious paper
▫ Aluminum foils
Used in areas difficult to clean and disinfect
- Air water syringe
- Dental light handles
- Electrical toggle switches
- Head rest
- X Ray unit heads

37. Waterlines and water quality
• Microbes exist in the dental unit water line as
biofilm.
• bacteria may include atypical mycobacteria,
pseudomonas, and Legionella
• CDC has recommended that dental unit
treatment water contain less than 500 colony-
forming units (cfu) per milliliter of bacteria.
• Disinfectants such as an iodophore or diluted
sodium hypochlorite that are used to clean the
system

38. • All waterlines must be fitted with non-return (anti-retraction) valves to help
prevent retrograde contamination of the lines by fluids from the oral cavity.
• Air and waterlines from any device connected to the dental water system
that enters the patient’s mouth (e.g. handpieces, ultrasonic scalers, and
air/water syringes) should be flushed for a minimum of two minutes at the
start of the day and for 30 seconds between patients

39. High risk infections & protocol to be followed for
treating high risk infectious patients
• Dental patients and Dental Health Care Workers (DHCWs) may be exposed to a
variety of microorganisms via blood or oral or respiratory secretions.
• These microorganisms may include human immunodeficiency virus (HIV),
hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus types 1 and
2, Mycobacterium tuberculosis
• Recently exposure to DHCWs and patients by Prions has come to limelight
• Prions are proteins that have been linked to fatal neurodegenerative disorder
commonly called as transmissible spongiform encephalopathies
J Endod 2007;33 442-446

40. Protocol to be followed :-
• High risk patients should be seen last
• Protective attire and barrier techniques
• Vaccines for dental health-care workers
• Use and care of sharp instruments and needles
• Cleaning and disinfection of dental unit and environmental surfaces
• Use single-use disposable items and equipment
• Consider items difficult to clean (e.g., endodontic files, broaches) as single-use
disposable
• Keep instruments moist until cleaned
• Clean and autoclave at 134°C for 18 minutes

41. Immunisation
• Dental personnel should maintain up-to-date immunization records that
include vaccination against:
▫ A) HEPATITIS B
▫ B) RUBELLA
▫ C) MEASLES
▫ D) MUMPS
▫ E) INFLUENZA
▫ F) POLIO
▫ G) TETANUS/DIPHTHERIA
MMR

42. Hepatitis B
(Recombinant )
Two doses IM 4 weeks apart, third dose 5
months after second
MMR
(Live Virus Vaccine)
One dose SC ..No booster
Influenza Vaccine
(inactivated whole virus and split –virus
vaccine)
Annual Vaccination
Tetanus –Diphtheria
(Toxoid)
Two doses IM 4 weeks apart, third dose 6
– 12 months after second.
Booster dose every 10 years
Varicella
(Live virus vaccine)
One dose SC for persons ages 12 months
to 12 years, Second dose 4 – 8 weeks after
first for those ages 13 and up
Recommended Vaccines for Oral Health Care workers

43. For HIV virus
After immediate exposure-
• Decontamination of wound
• Base line laboratory test for health care workers
• Selection of PEP regimen
• PEP regimen includes two NRTI typically zidovudine and
lamivudine
• Expanded regimen includes basic regimen plus nelfinavir and
efavirenz
• After this HIV screening at 6 weeks, 3 months, and 6 months

44. For HB
• Hepatitis B vaccine series should be initiated in non-HBV-immune health
care professionals
• Administration of prophylactic Hepatitis B immune globulin and initiation
of hepatitis B vaccines series should be done at different sites.
• Following an exposure HB and HC serology should be determined
• If a source patients is known to be HCV antibody positive baseline then
HCV serology and serum ALT should be obtained from exposed health
care professionals and after 4 weeks HCV viral load (HCV RNA PCR)
should be done
• HBV infections responds to 70-90% when HBIG is administered within 7
days.

45. Mycobacterium tuberculosis
• All dental healthcare professionals (DHCPs) should be educated regarding
the signs, symptoms, and transmission of tuberculosis
• All DHCPs who could have contact with persons with suspected or
confirmed cases of TB should have a baseline tuberculosis skin test
• Assess each patient for a history of TB, and document it on the medical
history.
The following applies to patients known or suspected to have active TB:
• The patient should be evaluated away from other patients and personnel.
• Elective dental treatment should be deferred until the patient is non-
infectious.
• Patients who require urgent dental treatment should be referred to a facility
with TB engineering controls and a respiratory protection program.

46. Creutzfeldt-Jakob Disease and Other
Prion Diseases
• Creutzfeldt-Jakob disease (CJD) belongs to a group of rapidly progressive,
invariably fatal, degenerative neurologic disorders.
• Prion diseases have an incubation period (time between infection and signs
of disease) of years and are usually fatal within one year of diagnosis.
• Theoretical risk of transmission of prion disease through dental treatment
emphasizes the need to maintain optimal standards of infection control and
decontamination procedures for all infectious agents including prions
J Can Dent Assoc 2006; 72(1):53–60

47. Applying First Aid after an Exposure Incident
Procedural Steps
• Stop operations immediately.
• Remove your gloves.
• If the area of broken skin is bleeding, gently squeeze the site to
express a small amount of visible blood.
• Wash your hands thoroughly, using antimicrobial soap and warm
water.
• Dry your hands.
• Apply a small amount of antiseptic to the affected area.
Do not apply caustic agents such as bleach or disinfectant
solutions to the wound.
• Apply an adhesive bandage to the area.

48. Office design
• Office design split into 3 distinct areas:
▫ a) Operator area
▫ b) Dental assistant area
▫ c) Sterilization and storage area
Inf. Cont. & manag. Haza. Mat. For dent.team,2013;pn145.

49. Instrument processing
• Contaminated instruments can transmit infections between patients,
correct reprocessing of instruments between each patient use is
essential
Steps Involved
• Presoaking
• Cleaning
• Packaging
• Sterilization
• Drying or cooling

50. Categories of instruments
Spaulding’s Classification

51. Presoaking
• Most disinfectants do not act in the presence of debris, so they should be
removed. It is easier to remove the debris before it dries.
• Placing the instrument in a presoak solution until time is available for full
cleaning prevents drying and begins to dissolve or soften the debris.
• Presoak solutions used are detergents, enzymes, phenols, quaternary
ammonium compounds.

52. • All items to be sterilized must be properly cleaned first to reduces bio-
burden
Ultrasonic cleaners
• These are safest and most efficient ways to clean instruments
• Ultrasonic cleaning is 9 times more effective than hand cleaning
Society for Infection Control in Dentistry 6:2, 1991
• An ultrasonic cleaning device provides fast and thorough cleaning without
damage to instruments
Cleaning

53. Instrument Containment
• Cloth packs, wraps, or plastic bags are suitable for instrument
containment if they are compatible with the method and temperature of
sterilization.
• Various kinds of instrument trays and cassettes are manufactured to
contain the instruments at chairside, and they can be placed in an
ultrasonic cleaner, rinsed, and packaged ready for sterilization.

54. Selection of Packaging materials
Method of sterilization Packaging materials
Steam
Paper / Plastic pouches /
Wrapped cassettes / Thin cloth
Chemical vapour
Paper wrap / Paper peel
pouches
Dry heat
Nylon plastic tubing /
Sterilization paper wrap / Foil

55. STERILIZATION
• Most instruments contact mucosa or penetrate oral tissues, it is
essential that reused instruments be thoroughly cleaned and
sterilized by accepted method that can be routinely tested and
monitored.
4 accepted method of sterilization -
1. Steam pressure sterilization (Autoclave)
2. Chemical vapor pressure sterilization (Chemiclave)
3. Dry heat sterilization (Dryclave)
4. Ethylene oxide sterilization(ETOX)
J Am Dent Assoc 123(Suppl):1–8, 1992

56. Autoclave
• Sterilization with steam under pressure is performed in a steam autoclave
• Time required at 1210 C is 15 mins at 15 lbs of pressure or 134o C at 30 lbs pressure
for 7 min
Advantages
• most rapid and effective for sterilizing cloth surgical packs and towel packs
Disadvantages ofAutoclave
• Items sensitive to heat cannot be sterilized
• It tends to corrode carbon steel burs and instruments

57. Sterilization Of Burs In Autoclaves
• Burs can be protected by keeping them submerged in a small amount of 2% sodium
nitrite solution.
• Prepare fresh sodium nitrite solution by adding 20gms of crystal to 1 liter of water
and place it in a perforated beaker containing burs.
• The solution should be above the burs by approximately 1cm
J Am Dent Assoc 110:629–633, 1985

58. Chemiclave
• Chemiclaves utilize chemical vapor for sterilization produced using formaldehyde-
and-alcohol formulation that is water-free
• operates at 131 C and 20 pounds of pressure for 30 min
Advantages
• Carbon steel and other carbon sensitive burs, instruments and pliers are sterilized
without corrosion
Disadvantages
• Items sensitive to elevated temperature will be damaged
• Towel and heavy clothing cannot be sterilized.

59. Dry Heat Sterilization
Conventional dry heat ovens:
• Most common time temperature cycles are 170°C (340°F) for 60 minutes, 160°C
(320°F) for 120 minutes, and 150°C (300°F) for 150 minutes.
• Recently, more rapid dry heat sterilizers (COX sterilizers) have become available;
these can be operated at 370°F for 6-, 8- or 12-minute cycles
Advantages
• Carbon steel instruments and burs do not rust, corrode, or lose their temper or
cutting edges if they are well dried before processing.
Disadvantages
• High temperatures may damage more heat-sensitive items such as rubber or plastic
goods.
• Sterilization cycles are prolonged at lower temperatures.

60. Ethylene oxide sterilization
• Best method of sterilization of complex instruments and delicate materials.
• Automatic devices sterilize items in several hours and operate at elevated
temperature well below 1000 C
• Less expensive device operates at room temperature to sterilize overnight
Advantages
• Units with large chambers hold more instruments or packs per cycle
Disadvantages
• Porous or plastic materials absorb the gas and require aeration for 24 hours or more
before it is safe for them to contact skin or tissues.

61. Boiling Water
• Boiling water does not kill spores and cannot sterilize instruments
• Incase of sterilizer breakdown - this method should be followed
• Well cleaned items must be completely submerged and allowed to boil at 1000 C for
10 mins
Disinfection, sterilization, and preservation, ed
4, Philadelphia, 1991, Lea & Febiger

62. Endodontic instruments sterilization
• Proper steam autoclaving reliably produced completely sterile
instruments.
• Salt sterilization and glutaraldehyde solutions may not be adequate
sterilization methods for endodontic hand files and should not be
relied on to provide completely sterile instruments
Journal of Endodontics; 1996;22; 6; 321-322.
• Files sterilized by autoclave and lasers were completely sterile.
Those sterilized by glass bead were 90% sterile and those with
glutaraldehyde were 80% sterile.
J Indian Soc Pedod Prevent Dent ;28;1;2010

63. Individual instruments can be sterilized in the following ways -
• Glass slab by swabbing with tincture of thimerosal, followed by a
double swabbing with alcohol.
• Gutta-percha cones may be kept in sterile screw capped vials
containing alcohol.
• To sterilize gutta-percha cone freshly removed from the box-
immerse in 5.2% sodium hypochlorite for 1 min, then rinse with
hydrogen peroxide and dry between 2 layers of sterile gauze.

64. • Silver cones are sterilized by passing them through a flame 3-4 times or by
immersion in hot salt sterilizer for 5 secs.
• Rubber dam is sterilized by ethylene oxide.
• Carbon steel instruments and burs are best sterilized by dry heat or
chemiclave.
• Sterilization dental cements, calcium sulphate is done by gamma radiation

65. Disinfection of impression
• Before disinfection, dental impressions must be rinsed to remove debris,
saliva and blood. Disinfection of impressions is done by immersion in
compatible disinfecting agent for 15 to 30 minutes depending on
manufacturer’s recommendation for proper disinfection.
Type of Impression Material and Recommended Disinfectants
1. Alginate – Immerse in iodophors or 0.5% hypochlorite
2. Polysulfide – Immerse in glutaraldehyde, iodophor, 0.5% hypochlorite
or phenolic
3. Silicone – Immersion in any disinfectant
4.Polyether – Spray and wrap in iodophor, 0.5% hypochlorite, phenolic
disinfectants.
5. Hydrocolloid – Immerse in iodophor, 0.5% hypochlorite
6. Impression Compound – Immerse in iodophor, 0.5% hypochlorite

66. Sterilization Monitoring
• Biological indicators :
▫ Bacillus stereothermophilus ( steam or chemiclave )
▫ Bacillus subtilus (dry heat )
• Chemical indicators
▫ Color change – strips or tapes
• Physical indicators
▫ Routine observations of dials / gauges indicating time ,
temperature & pressure