INFECTION CONTROL IN DENTISTRY

Dr.Anirudh Singh ChauhanPG 1st year

Department of PeriodonticsJAIPUR DENTAL COLLEGE

WHY INFECTION CONTROL ??

CONTENTS

• INTRODUCTION• QUESTIONS TO THINK ABOUT….• TRANSMISSION OF INFECTIONS• CHAIN OF INFECTION• STANDARD PRECAUTIONS• IMMUNIZATION FOR DENTAL PROFESSIONALS • PROTECTION OF THE DENTIST• STERILIZATION• DISINFECTION OF DENTAL SETUP• DENTAL WASTE MANAGEMENT• CONCLUSION

INTRODUCTION

• The oral cavity is an environment in itself which provides a nutritive medium for bacterial growth. The mouth harbors bacteria and viruses from the nose, throat and respiratory tract as well.

• Any dental procedure that has the potential to aerosolize saliva will cause airborne contamination with organisms from some or all of these sources.

• Dentists have a duty to take appropriate precautions to protect their patients , their staff and more importantly THEMSELVES from the risk of cross-infection.

HISTORY

• Zaccharias Jansen in 1590 and Robert Hooke in 1660 opened the world of microbes to mankind by their inventions of microscopes

• It was Anthony Van Levenhook who first described microorganisms

• Joseph Lister between 1865 to 1891 delineated the principles of wound infection and asepsis

• Further pioneering efforts of Louis Pastuer added new

dimensions to the field of sterilisation

• Input by various researchers like John Tyndall, Robert Koch

etc further accelerated the progress, when finally in 1890’s

the advent of steam sterilizers, sterile gowns, drapes and

gloves emerged

• The modern infection control prevention and sterilization

guidelines were stated by the CDC (Centre for Disease

Control) in 1973 and specific dental infection control

guidelines by the ADA and OSHA in 1978 revised in 1985 and

1988

Thus infection control involves-

1. Reduction of pathogen concentration to allow normal host resistant mechanisms to prevent infection

2. Break the cycle of infection and eliminate cross infection

3. Treat every patient and instrument as potentially infectious and therefore employ universal safety precautions

4. Protect patients and personnel from occupational infection

Questions to think about…..

• How can you “break the chain” of infection in your office

today?

• Are there areas of your daily practice where cross-

contamination could be happening?

• How can you make changes that will prevent cross-

contamination in your daily practice?

What factors influence the development of infection?

• The number of microorganisms and duration of exposure (how many and for how long?)

• Virulence of organisms (ability to cause disease; pathogenic properties)

• Immune status of the host (body defenses)

• The goal of an infection control program is to “break the chain” of infection by consistently practicing protocols which would prevent the infectious agent from moving to one host to another and preventing cross-contamination.

**Application to Practice**

How are diseases transmitted in the dental setting?

From the patient to the dental worker

From the dental worker to the patient

From one patient to another

From the dental office to the community

Transmission can be…

1) Direct Contact with blood, oral fluids, or other patient materials;

2) Indirect Contact with contaminated objects (e.g., instruments, equipment, or environmental surfaces);

3) Droplets - (e.g., by coughing, sneezing or talking)4) inhalation of airborne microorganisms that can

remain suspended in the air for long periods

The Infectious Process“Chain of Infection”

Infectious agent

Port of Exit

Transmission

Port of Entry

Susceptible hostReservoir

The chain of infection example

Hepatitis BThe bloodstream

Bleeding wound

Direct via needle stick

Puncture wound

UnvaccinatedDental worker

Infectious agent

Port of Exit

Transmission

Port of Entry

Susceptible hostReservoir

STANDARD PRECAUTIONS

• Standard precautions integrate and expand the elements of universal precautions into a standard of care designed to protect HCP and patients from pathogens that can be spread by blood or any other body fluid, excretion, or secretion

Centre for Disease Control and Prevention, USA1996

IMMUNIZATION FOR DENTAL PROFESSIONALS

• Dental Professionals are at very high risk of acquiring infection through CROSS CONTIMINATION in a dental setup during dental procedures.

• Thus there is a need for Dental professionals to get theVaccinations done on time.

WHY SHOULD PATIENT HAVE ALL THE NEEDLES !!!

Preventing Blood borne Transmission of Pathogens

A. HBV VACCINATION• We all MUST get HBV vaccination series as we have the

potential occupational exposure to blood or other potentially infectious material

Hepatitis B Vaccine

• PRE-EXPOSUREHepatitis B (HB) recombinant vaccine – 2 doses IM,

4 weeks apart and the third dose should be administered 5 months after the second dose. Booster doses not necessary.

• POST-EXPOSUREHepatitis B immuno globulin (HBIG) – 0.06mL/kg

IM as soon as possible after the exposure. A second dose of HBIG should be administered if the HB vaccine series has not been started.

Other Recommended Vaccines…

• Flu (Influenza) – to be taken annually

• MMR (Measles, Mumps & Rubella) – 2 doses with a gap of

28 days

• Varicella (Chicken pox) – 2 doses, 1 month apart (if u have not

had chicken pox or vaccinated earlier)

• Tdap (Tetanus, Diphtheria, Pertusis) – one time dose and

booster dose every 10 years (Pregnant HCWs need to get a dose of

Tdap during each pregnancy) Advisory committee for Immunization Practices (ACIP) 2011

HAND HYGIENE

Hand hygiene is a general term applying to processes aiming to reduce the number of microorganisms on hands.

• This includes either the application– Alcohol-based hand rub (ABHR)– The use of soap/solution (plain or antimicrobial)– Water, followed by patting dry with single use

towels.

HAND CARE

• Hands must be well cared for, because intact skin is a first line defense mechanism against infection.

• Lacerated, chafed or cracked skin can allow entry of microorganisms, any cuts or open wounds need to be covered with a waterproof dressing.

• All hand & wrist jewellery should be removed prior to putting on gloves as its presence compromises the fit and integrity of gloves and also promotes significant growth of skin microorganisms.

• All fingernails must be kept short to prevent glove tears and to allow thorough cleaning of the hands.

PERSONAL PROTECTIVE EQUIPMENT

• The wearing of protective personal clothing and equipment where aerosols are likely to be generated is an important way to reduce the risk of transmission of infectious agents.

• Barrier protection including gloves, mask, eyewear and gown must be removed before leaving the work area (e.g. dental surgery, instrument processing or laboratory areas).

GLOVES

• Dental practitioners and clinical support staff must wear gloves whenever there is risk of exposure to blood, saliva or other body secretions or when hands will come in contact with mucous membranes.

• Wearing gloves does not replace the need for hand hygiene because hands may still become contaminated.

• Gloves must be removed or overgloves worn before touching any environmental surface without a barrier or before accessing clean areas.

• If the dental practitioner, clinical support staff member or patient has a proven or suspected allergy to latex, alternatives such as neoprene or nitrile gloves must be used.

MASKS

• In the dental surgery environment, the most common causes of airborne aerosols are the high speed air rotor handpiece, the ultrasonic scaler and the triplex syringe.

• The aerosols produced may be contaminated with bacteria and fungi from the oral cavity (from saliva and dental biofilms), as well as viruses from the patient’s blood.

• Because masks protect the mucous membranes of the nose and mouth, they must be worn wherever there is a potential for splashing, splattering or spraying of blood, saliva or body substances, or where there is a probability of the inhalation of aerosols with a potential for transmission of airborne pathogens.

• The filtration abilities of a mask begin to decline with moisture on the inner and outer surfaces of the mask after approximately 20 minutes.

• MASKS MUST - cover both the nose and mouth, and where possible be folded out fully to cover the chin and upper neck; and be removed by touching the strings and loops only

MASKS MUST NOT - be worn loosely around the neck while the dental

practitioner or clinical support staff member walks around the premises, but be removed and discarded as soon as

possible after use.

EYE PROTECTION• Dental practitioners and clinical support staff must wear

protective eyewear where there is the potential for penetrating injury or exposure to aerosols, splattering or spraying with blood, saliva or body substances.

• Protection from projectiles is particularly important during scaling, when using rotary instruments, when cutting wires and when cleaning instruments and equipment.

• Eyewear must be optically clear, anti-fog, distortion-free, close-fitting and should be shielded at the sides.

• All patients must be offered protective eyewear. If patients refuse to wear the protective glasses, the risks should be explained and the refusal noted in their dental records.

• With regard to cleaning, eyewear for patients may be either single use or can be reused after cleaning with detergent and water.

PROTECTIVE CLOTHING

• Protective clothing (e.g. reusable or disposable gown, laboratory coat or uniform) should be worn while treating patients when aerosols or splatter are likely to be generated or when contamination with blood or saliva is possible.

• Items of protective clothing must be changed as soon as possible when they become visibly soiled or after repeated exposure to contaminated aerosols.

FOOTWEAR

• Dental practitioners and clinical support staff should wear enclosed footwear that will protect them from injury or contact with sharp objects (e.g. accidentally dropped sharps or spilt chemicals).

PATIENT PREPARATION

• Betadine preparation of patient before any surgical procedure to be performed.

• PRERINSE- Rinsing of mouth with 0.2% Chlorhexidine prior to treatment reduces the aerosols contents in the oral cavity.

STERILIZATION

• PHYSICAL

• CHEMICAL

• Physical is classified into

1. Sunlight

2. Drying

3. Dry heat : FLAMING, INCINERATION, HOT AIR

4. Moist heat : PASTEURATION, BOILING, STEAM UNDER

NORMALPRESSURE, STEAM UNDER PRESSURE

5. Filtration : CANDLES, ASBESTOS PAD, MEMBRANES

6. Radiation : MICROWAVE, X-RAYS, UV Rays

7. Ultrasonic and sonic vibrations

1. ALCOHOLS: ETHYL, ISOPROPYL, TRICHLOROBUTANAL

2. ALDEHYDES: FORMALDEHYDE, GLUTERALDEHYDE

3. DYES

4. HALOGENS

5. PHENOLS

6. SURFACE ACTIVE AGENTS

7. METALLIC SALTS

8. GASES: ETHYLENE OXIDE, FORMALDEHYDE, BETAPROPIOLACTONE

9. HYDROGEN PEROXIDE PLASMA / VAPORS

Chemical is classified into :

A. Open flaming:

B. Hot air oven The temperature cycles for dry heat sterilization are as follows: Temprature Time

121˚ C 6-12 hours 140˚ C 3 hours 150˚ C 2 & ½ hours 160˚ C 2 hours 170˚C 1 hour 190˚- 204˚ C 15 minutes

C.GLASS BEAD AND HOT SALT STERILISER

• The glass bead sterilizer uses a metal cup with glass beads of 1 mm diameter in it

• The hot salt container uses ordinary table salt• The temperature range for both varies from 425oF TO 475oF • Both are used to sterilize endodontic instruments and scaler

tips.• The hot salt sterilizer is better than the glass bead sterilizer

because the glass beads stick to the instruments and clog the root canal.

• Also the material used in the hot salt sterilizer is ordinary table salt which is readily available

Electric glass bead steriliser

D. Steam under pressure

• Moist heat in the form of pressurized steam is regarded as the most dependable method for destruction of all forms of bacterial life including spores.

• This method is incorporated into a device called the AUTOCLAVE.

• Over a hundred years ago, French & German microbiologists developed the autoclave.

• The basic principle is that when the pressure of a gas increases the temperature increases

• As the water molecules in steam become more energized,

their penetration also increases

• Same principle is used in home

pressure cooker.

• It is important to note that sterilizing

agent is moist heat not the pressure.

• Pressure Temp. Time 15 psi 121 C 20 min. 20 psi 134 C 3 – 5 min. (Flash method)

E. Autoclave

Radiation

• Visible light is a type of radiant energy detected by the

sensitive cells of eye. Wavelength is 400-800 nm.

• Radiation may have sufficient energy to remove an electron

completely from an atom and produce an electrical change

(ionization), or to raise electron to high energy state

(excitation).

NON IONISING RADIATION

• This include infrared rays and ultraviolet rays

• Infra red are used for mass sterilization of syringes

ULTRAVIOLET LIGHT• Ultraviolet germicidal radiation (UVGI) is a disinfection method

that uses ultraviolet (UV) light at sufficiently short wavelength to kill microorganisms

• UV light is used to limit airborne or surface contamination in a hospital room, pharmacy food service operation.

• UV light does not penetrate liquids or solids and it may cause damage to the human skin.

• used primarily in medical sanitation

and sterile work facilities

IONIZING RADIATION

• X-rays and gamma rays have wave length shorter than UV light

• Can be used for syringe sterilization, suture materials, dressing materials etc.

MICROWAVE

• Microwaves have a wavelength longer than UV light.

• In a microwave oven waves are absorbed by water

molecules.

• The molecules are set into a high speed motion, and the

heat of friction is transmitted , which become hot rapidly.

LASER

• LASER – Light Amplification by Stimulated Emission of

Radiation

• Recent experiments indicate that laser beams can be used to

sterilize instruments & the air in operating rooms, as well as

for a wound surface.

• Various types include CO2 , Argon ,Nd-YAG etc

Ultrasonic vibrations

• They are high frequency sound waves beyond the range of human ear.

• When propagated in fluids ultrasonic vibrations cause formation of microscopic bubbles or cavities and the water appears to boil.

• Some observers call this cold boiling. • The cavities rapidly collapse & send out shock waves. The formation

and implosion of the cavities is known as cavitation. Microorganisms in the fluid are quickly disintegrated by the external pressures.

• The current trend is to use ultrasonic as a cleaning agent to follow the process by sterilization in an autoclave.

FUMIGATION

• The operating room is fumigated with the help of 40% formaldehyde (350 ml) added with KMnO4 (174 Gms) for a room measuring 1000 cubic Ft.

• This mixture produces an exothermic reaction and should be kept in a stainless steel bowl in the Operatory Room

• The fumes rapidly spread in the OR and kill the microorganisms.

• The OR should be closed in an air tight manner and sealed to prevent leakage of fumes.

• Fumigation is done weekly and gates should be kept closed for 24 hours

DISINFECTION OF DENTAL UNIT AND ENVIRONMENTAL

SURFACES

DENTAL UNIT

•Cleaned by DISPOSABLE TOWELING

•EPA-ENVIRONMENTAL PROTECTIVE AGENCY

•use an EPA registered hospital disinfectant

•Cleaning Agents Like

PHENOLICS, IODOPHORS, CHLORINE CONTAINING compounds

ENVIRONMENTAL SURFACES

• CLINICAL CONTACT SURFACES–High potential for DIRECT

CONTAMINATION from spray or spatter or by contact with gloved hand.

• HOUSEKEEPING SURFACES–Do not come into contact with patients or

devices–LIMITED RISK of disease transmission

CLINICAL CONTACT SURFACES

CLEANING CLINICAL CONTACT SURFACES

• Risk of transmitting infections greater than for housekeeping surfaces.

• Surface barriers can be used and changed between patients.

OR

• Clean then disinfect using an EPA-registered low- (HIV/HBV claim) to intermediate-level (tuberculocidal claim) hospital disinfectant.

HOUSEKEEPING SURFACES

Cleaning Housekeeping Surfaces

• Routinely clean with SOAP AND WATER or an EPA-REGISTERED DETERGENT/HOSPITAL DISINFECTANT routinely

• Clean MOPS AND CLOTHS and allow to dry thoroughly before re-using.

• Prepare FRESH CLEANING AND DISINFECTING SOLUTIONS daily and per manufacturer recommendations.

DISINFECTION AND THE DENTAL LABORATORY

BASICS OF LABORATORY

• 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

• 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

INCOMING ITEMS

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”

MANAGEMENT OF MEDICAL WASTE

‘Bio-medical waste’ means any solid and/or liquid waste, including its container and any intermediate product, which is generated during the diagnosis, treatment or immunization of human beings or animals or in research

• Inappropriate handling of sharps, both during and after

treatment, is the major cause of penetrating injuries which

involve potential exposure to blood borne diseases in the

dental surgery.

• Sharp instruments such as scalpels and scalers must never be

passed by hand between dental staff members and must be

placed in a puncture-resistant tray or bowl after each use.

• Do not recap used needles by using both hands or any other technique that involves directing the point of a needle toward any part of the body.

• Use either a one-handed scoop technique or a mechanical device designed for holding the needle cap when recapping needles

MANAGEMENT OF DENTAL WASTE

• Use a color-coded or labeled container that prevents leakage (e.g., biohazard bag) to contain non sharp regulated medical waste.

• Used disposable needle syringe combinations, empty or partially used cartridges of local anaesthetic solution, burs, needles, scalpel blades, orthodontic bands, endodontic files and other single use sharp items must be discarded in clearly labelled , puncture and leak proof containers.

• Pour blood, suctioned fluids or other liquid waste carefully into a drain connected to a sanitary sewer system.

• Sharps containers must be placed in a safe position within the

treatment room to avoid accidental tipping over and must be

out of the reach of small children.

• Sharps containers must be sealed when they have been filled

to the line marked on the container, and then collected by

licensed waste contractors for disposal according to local

waste management regulations.

Environmental Infection Control

• Clean spills of blood and decontaminate surface with an EPA-

registered hospital disinfectant with low - to intermediate-

level activity, depending on size of spill and surface porosity

• Avoid using carpeting and cloth-upholstered furnishings in

dental operatories, laboratories, and instrument processing

areas

SPECIAL CONSIDERATIONS

• Do not surface-disinfect, use liquid chemical sterilants, or ethylene oxide on handpieces and other intraoral instruments

• Wear gloves when exposing radiographs and handling contaminated film packets.

• Do not administer medication from a syringe to multiple patients, even if the needle on the syringe is changed

• Do not combine the leftover contents of single-use vials for later use

• During transport, place biopsy specimens in a sturdy, leakproof container labeled with the biohazard symbol

• Clean and place extracted teeth in a leakproof container, labeled with a biohazard symbol

• Dispose of extracted teeth as regulated medical waste unless returned to the patient

• Do not dispose of extracted teeth containing amalgam in regulated medical waste intended for incineration

CONCLUSION

• “PREVENTION IS BETTER THAN CURE”- a proverb well suited to sterilization.

• Promotion of a safety climate is the cornerstone of prevention of transmission of pathogens in the health care.

• Provision of adequate staff and supplies, together with leadership and education of health workers, patients and visitors, is critical for an enhanced safety climate in health-care settings.

• Standard precautions should be the minimum level of precautions used while providing care for all patients

Reference

• Guidelines for Infection control in Dental Health care settings (2003)–Dr.William G.Kohn et al, Division of Oral Health, National Centre for Chronic Disease Prevention and Health Promotion, CDC

• Guidelines for Infection Control in Dental Health Care Settings (2012)- Australian dental Association

• Cohen’s Pathways of the Pulp, Tenth Edition• Fundamentals of microbiology- Frobisher 9th Edition Saunders

• Gupta DS, Borle RM. Operation theatre discipline. J Indian Dent Assoc. 1983 Nov;55(11):437-40.

• Reinhardt PA, Gordon IG. Infectious and medical waste management. Chelsea, MI: Lewis Publishers, 1991.

THANK YOU!!