INFECTION CONTROL IN DENTISTRY

2

CONTENTS Introduction Mode of Transmission Mode of Infection control Objective of Infection control Operatory Asepsis Personal Protection Barrier Sterilization Disinfection Laboratory Infection Control Clinical Waste Disposal.

3

Definitions• 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.

4

STERILIZATION: •Use of a physical or chemical procedure to destroy all microorganisms including substantial numbers of resistant bacterial spores.

5

• Sterilization means the destruction of all life forms. (Ronald B Luftig).

• Sterilization is the process of killing or removing all viable organisms. (MIMS – PLAYFAIR)

6

• STERILE: – Free from all living microorganisms;

usually described as a probability (e.g., the probability of a surviving microorganism being 1 in 1 million).

7

DISINFECTION: •Destruction of pathogenic and other kinds of microorganisms by physical or chemical means.

8

• Disinfection is less lethal than sterilization, because it destroys the majority of recognized pathogenic microorganisms, but not necessarily all microbial forms (e.g., bacterial spores).

• Disinfection is a process of removing or killing most, but not all, viable organisms.

9

• DISINFECTANT: A chemical agent used on inanimate objects to destroy virtually all recognized pathogenic microorganisms, but not necessarily all microbial forms (e.g., bacterial endospores).

10

• ASEPSIS: prevention of microbial contamination of living tissues or sterile materials by excluding, removing or killing microorganisms.

11

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

Modes of Diseases Transmission

12

MODES OF TRANSMISSION:

Six links in chain of transmission of infection

Chain of infection

13

OBJECTIVES OF INFECTION CONTROL

Reduce

Implement

Simplify

Protect

14

Why , Who and what Why is infection control necessary in dentistry ?•Dental staff and patients may be exposed to a wide variety of pathogenic microorganisms .

15

• Who is responsible for infection control in the dental office ?– Each member of the dental team must follow the

recommended guidelines .

16

• What should be done to prevent the transmission of disease in the dental office ?

17

The most effective ways to prevent the transmission of diseases includes : 1) Hand washing2) Gloves3) Face masks4) Protective eye wear5) Protective clothing 6) Instrument sterilization and disinfection

18

Diseases Transmission in Dental OfficeThe dental office should have an infection control program to prevent the transmission of disease from the following :Patient to dental teamDental team to patientPatient to patientDental office to community ( include dental team’s family )Community to dental office to patient

Diseases Transmission in Dental Office

19

•To prevent such infections, following is a list of all those procedures and precautions that together constitute infection control.

20

•These guidelines should be followed each time treatment is performed because we are never certain of the patient's status, either because they themselves do not know or because they have chosen not to inform their healthcare providers of their condition.

•Following these guidelines for every patient is called "Standard Precautions".

21

1. Immunization2. Patient screening3. Hand washing4. Barrier techniques - • Personal Protective Equipment (PPE) • Rubber dam, Pre-procedural rinsing5. Needle & sharp instrument safety • Occupational Exposure To Blood/Body Fluids6.Instruments sterilization and disinfection7.Surface disinfection8. Radiographic asepsis9. Laboratory asepsis10.Infectious dental waste management & disposal

Standard Precautions

22

Personal protective equipment ( PPE ) •OSHA requires the employer to provide employees with appropriate personal protective equipment . •Examples of PPE: 1- Protective clothing 2- Surgical masks 3- Face shields 4- Protective eyewear 5- Disposable patient treatment gloves 6- Heavy-duty utility gloves

23

These PPE must be used whenever you : Performing tasks that could produce

splash or spatter . Any contact with body fluids Perform other clinical activities that

require handling contaminated items e.g. radiographs , impressions , dentures or contaminated equipment and surfaces .

24

HAND HYGIENE Hand washing is the single most important procedure for preventing the spread of infection. So , you must wash your hands each time before you put on gloves and immediately after you remove gloves .

25

• Hand washing is also required if you touch contaminated instruments or surfaces during working

• We should always use liquid soap during hand washing . Bar soap should never be used because it may transmit contamination.

• Visibly dirty• After touching

contaminated objects with bare hands

• Before and after patient treatment (before glove placement and after glove removal)

HANDS NEED TO BE CLEANED WHEN

27

OPERATORY ASEPSIS• In the dental operatory, environmental

surfaces (i.e., a surface or equipment that does not contact patients directly) can become contaminated during patient care.

28

• Certain surfaces, especially ones touched frequently (e.g., light handles, unit switches, and drawer knobs) can serve as reservoirs of microbial contamination, although they have not been associated directly with transmission of infection to either personnel or patients.

29

• Transfer of microorganisms from contaminated environmental surfaces to patients occurs primarily through personnel hand contact

30

A. Infection Control During the Pretreatment Period

• The process of infection control begins during the period of preparation for clinical treatment.• Paying attention to infection control at this time has several payoffs.

31

• In addition to reducing the risk of transmission of infectious agents during patient care, thinking ahead will make the treatment session more efficient and will also make the post treatment infection control process easier and more effective.

32

1. Remove unnecessary items from the dental procedure area : The dental procedure area should be arranged to facilitate a thorough cleaning following each patient.

33

2. Preplan the materials needed during treatment.- Set out all instruments, medications, impression materials, and other items that are needed for a procedure. - Thinking ahead minimizes the need to search for additional items or to enter cabinets and drawers once gloves have become contaminated.

34

3. Utilize disposable items whenever possible:The use of disposable items saves time during cleanup and decontamination and solves the problem of proper reprocessing.

35

• 4. Use prearranged tray set-ups for routine or frequently performed procedures.–Helps to eliminate the need to go into

cabinets once you have started a procedure.

36

5.Use individualized, sterilized bur blocks for each procedure

• Using individualized bur blocks containing only the burs required for that procedure helps to eliminate the contamination of other, unneeded burs and to make clean-up easier.

37

6. If indicated, have the rubber dam setup on the tray.When a rubber dam will be used during a clinical procedure, it also should be included on the tray setup. In addition, include those items needed for high-velocity evacuation.

38

7. Identify those items that will become contaminated during treatment.• While preparing the dental procedure area prior to beginning a clinical procedure, consider which items will become contaminated during treatment. • Examples of such surfaces include countertops, light handles, X-ray unit heads, tray tables etc. • Decide whether to use a barrier, e.g., plastic wrap to prevent contamination of these surfaces and items or to disinfect them when the procedure is complete.

39

Surface barriers :• Surface barriers are used to prevent contamination on the surface underneath.• All the surface barriers should be resistant to fluids in order to prevent microorganisms in saliva, blood, and other liquids from soaking through the barrier and reach the surface underneath.

Chair Drapes

40

41

42

43

8. Review patient records before initiating treatment and place radiographs on the view box.

• Do not leave the record on the countertop or handle it after beginning treatment. • Place the record in a drawer or out of the dental procedure area, so that it doesn’t become contaminated. • Entries into the record should be done before and after the procedure.

44

45

9. Prepare personnel involved in patient care.• An essential pretreatment procedure is the preparation of all personnel involved in patient care. • This includes the utilization of personal protective equipment (gown, eyewear, mask and gloves) and hand hygiene.

46

47

B. Infection Control during the treatment Period (Chairside Infection Control ) :

The infection control procedures described in

the previous period will help you to reduce the risk of transmission of infectious agents. During treatment there are additional precautions that can be taken to further reduce infection risks.

48

1. Use care when receiving, handling, or passing sharp instruments

2. Take special precautions with syringes and needles.

3. Use a rubber dam whenever possible4. Avoid touching unprotected switches,

handles and other equipment once gloves have been contaminated.

5. Avoid entering cabinets once gloves have been contaminated.

49

50

51

Continue to wear personal protective equipment during clean-up: After patient care is completed, begin the cleaning and disinfection process by removing contaminated gloves used during treatment, wash your hands and use the utility gloves before beginning the clean up. Continue to wear protective eyewear, mask, and gown.

C. Infection Control During the Post- Treatment Period

52

Remove all disposable barriers : All of the barriers placed before treatment, including light handle covers and countertop barriers, should be removed.

Clean and disinfect all items not protected by barriers.

53

Cleaning and disinfection of the dental treatment room surfaces are important components in an effective infection control program

The laboratory studies have proved that microorganisms may survive on environmental surfaces for long time . For example, Mycobacterium tuberculosis may survive for weeks

54

STERILIZATION AND DISINFECTION OF DENTAL INSTRUMENTS

56

DENTAL INSTRUMENTS

Classification based on risk of transmission and need of sterilization

-CRITICAL -SEMI-CRITICAL -NON-CRITICAL

57

CRITICAL INSTRUMENTS• Penetrate MUCOUS MEMBRANES or CONTACT BONE,

BLOODSTREAM, or other normally sterile tissues

• HEAT STERILIZE between uses or use sterile single-use, DISPOSABLE devices

• Examples include SURGICAL INSTRUMENTS, SCALPEL BLADES, PERIODONTAL SCALERS, AND

SURGICAL DENTAL BURS

58

SEMI-CRITICAL INSTRUMENTS• Contact MUCOUS MEMBRANES but do NOT

PENETRATE SOFT TISSUE

• HEAT STERILIZE or HIGH-LEVEL DISINFECT

• Examples: DENTAL MOUTH MIRRORS, AMALGAM CONDENSERS, AND DENTAL HANDPIECES

59

NONCRITICAL INSTRUMENTS AND DEVICES

• Contact intact SKIN

• Clean and disinfect using a LOW TO INTERMEDIATE LEVEL DISINFECTANT

• Examples: X-RAY HEADS, FACEBOWS, PULSE OXIMETER, BLOOD PRESSURE CUFF

60

STERILIZATION• Stages for instrument sterilization:1. Presoaking2. Cleaning3. Corrosion control and lubrication4. Packaging5. Sterilization6. Handling sterile instruments7. Storage8. Distribution

61

Agents used in sterilization

• Physical agents:1. Sunlight2. Drying3. Dryheat: flaming, incineration, hot air 4. Moist heat: pasteurization, boiling, steam under

pressure, steam under normal pressure.5. Filtration: candles asbestos pads, membranes6. Radiation7. Ultrasonic and sonic vibrations

62

• Chemical agents:1. Alcohols: ethyl, isopropyl, trichlorobutanol2. Aldehydes: formaldehyde, glutaraldehyde3. Dyes4. Halogens5. Phenols 6. Surface-active agents7. Metallic salts8. Gases: ethylene oxide, formaldehyde, beta

propiolactone.

63

The 4 accepted METHODS OF STERILIZATION are:

• Steam pressure sterilization (autoclave) • Chemical vapor pressure sterilization-

(chemiclave)• Dry heat sterilization (dryclave) • Ethylene oxide sterilization

64

AUTOCLAVE • Sterilization with STEAM UNDER PRESSURE• Time required at 1210 C is 15 mins at 15 lbs of

pressure.

Advantages• Rapid and effective • Effective for sterilizing cloth surgical packs and towel packs

Disadvantages• Items sensitive to heat cannot be sterilized• It tends to corrode carbon steel burs and instruments

65

CHEMICLAVING Sterilization by CHEMICAL VAPOR UNDER

PRESSURE • operates at 1310 C and 20 lbs of pressure.• They have a cycle time of half an hour.

66

• Advantages • Carbon steel and other carbon sensitive burs,

instruments and pliers are sterilized without rust or corrosion

• Disadvantages• Items sensitive to elevated temperature will be

damaged• Instruments must be very lightly packed.• Towel and heavy clothing cannot be sterilized.

67

68

Dry Heat Sterilization Conventional dry heat ovens:• Achieved at temperature above 1600 C.• Have heated chambers that allow air to circulate by gravity

flow.• 6-12mins is required for sterilization

69

• Disadvantages• Without careful calibration, more chances

sterilization failures– The most accurate way to calibrate a

sterilization cycle is by using external temperature gauge (pyrometer) attached to a thermocouple wire.

70

71

ETHYLENE OXIDE STERILIZATION (ETO)

MOBILE FUMIGATOR

72

• Advantages:1. Operates effectively

at low temperatures2. Gas is extremely

penetrative3. Can be used for

sensitive equipment like handpieces.

4. Sterilization is verifiable

• Disadvantages:1. Potentially

mutagenic and carcinogenic.

2. Requires aeration chamber ,cycle time lasts hours

3. Usually only hospital based.

Sterilization Monitoring Types of Indicators

• Mechanical –Measure time, temperature, pressure

• Chemical –Change in color when physical parameter is

reached• Biological (spore tests)–Use biological spores to assess the

sterilization process directly

74

STERILIZATION METHOD SPORE TYPE INCUBATION TEMPERATURE

AUTOCLAVE Bacillus stearothemophilus 56°C

CHEMICAL VAPOR

DRY HEAT Bacillus subtilis 37°C

ETHYLENE OXIDE

Gamma radiation B. Pumilus E601 370C

Sterilization monitoring has four components: 1. a sterilization indicator on the instrument bag,

stamped with the date it is sterilized, 2. daily color-change process-indicator strips,3. weekly biologic spore test, and 4. documentation notebook.

75

STORAGE AND CARE OF STERILE INSTRUMENTS

• Storage areas should be dust proof, dry, well ventilated and easily accessible for routine dental use.

• Sterile materials should be stored atleast 8-10 inches from the floor, atleast 18 inches from the ceiling, and atleast 2 inches from the outside walls.

76

• Items are not stored in any location where they can become wet.

• Items should be positioned so that packaged items are not crushed, bent, crushed, compressed or punctured.

• Outside shipping containers and corrugated cartons should not be used as containers in sterile storage areas.

• Ultra violet chambers and formalin chambers are now commonly used for storage of instruments.

77

DISINFECTION OF DENTAL UNIT AND ENVIRONMENTAL SURFACES

78

DISINFECTION

• Disinfection is always at least a two-step procedure:

• The initial step involves vigorous scrubbing of the surfaces to be disinfected and wiping them clean.

• The second step involves wetting the surface with a disinfectant and leaving it wet for the time prescribed by the manufacturer.

79

• The ideal disinfectant has the following

properties:1. Broad spectrum of activity2. Acts rapidly3. Non corrosive4. Environment friendly5. Is free of volatile organic compounds6. Nontoxic & nonstaining

80

• High-level disinfection: Disinfection process that inactivates vegetative bacteria, mycobacteria, fungi, and viruses but not necessarily high numbers of bacterial spores.

81

Intermediate-level disinfection: Disinfection process that inactivates vegetative bacteria, the majority of fungi, mycobacteria, and the majority of viruses (particularly enveloped viruses) but not bacterial spores.

82

• Low-level disinfectant: Liquid chemical germicide. OSHA requires low-level hospital disinfectants also to have a label claim for potency against HIV and HBV.• Gigasept which contains succindialdehyde and dimethoxytetrahydrofuran are used for disinfection of plastic and rubber materials eg: dental chair

83

BASICS OF LABORATORY IC• Need COORDINATION between DENTAL OFFICE

AND LAB

• Use of proper methods/materials for handling and decontaminating soiled incoming items

• All contaminated INCOMING ITEMS should be cleaned and DISINFECTED before being HANDLED BY LAB PERSONNEL, and before being returned to the patient

84

85

INCOMING ITEMS• Rinse under running tap

water to remove blood/saliva

• Disinfect as appropriate• Rinse thoroughly with tap

water to remove residual disinfectant

• No single disinfectant is ideal or compatible with all items

86

OUTGOING ITEMS• Clean and disinfect before

delivery to patient• After disinfection: rinse and

place in plastic bag with diluted mouthwash until insertion

• Do not store in disinfectant before insertion

• Label the plastic bag: “This case shipment has been disinfected with ______ for _____ minutes”

87

REFERENCES:

• Operative dentistry, infection control, 4th edition, sturdevent.

• Sterilization and disinfection of dental instruments by ADA

• Disinfection & sterilization of dental instruments TB MED 266, 1995

• CDC, guidelines for disinfection & sterilization in health care facilities 2008.

• CDC guidelines for infection control in dental health care settings, Dec19, 2003/vol.52.