INFECTION CONTROL IN INFECTION CONTROL IN DENTAL PRACTICEDENTAL PRACTICE

Dr Arun George MDS Maxillofacial Surgeon, IndiaMar Baselios Dental College

STERILIZATION

INSTRUMENT MANAGEMENT

Why Is Infection Control Why Is Infection Control Important Important

in Dentistry?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

Dental patients and dental health care workers may be exposed to a variety of microorganisms such as bacteria, viruses, and fungi during dental treatment

Among these, the diseases of foremost concern are infections caused by

Human immunodeficiency virus (HIV) Hepatitis viruses B, C, and D Mycobacterium tuberculosis

Infections may be transmitted in the dental operatory through the following routesDirect contact with blood, oral fluids, or other secretionsIndirect contact with contaminated instruments, operatory equipment, or environmental surfacesContact with airborne contaminants present in either droplet spatter or aerosols of oral and respiratory fluids

Modes of TransmissionModes 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

Route of transmissionRoute of transmission

Inoculation: Direct contact of previously damaged skin

or mucous membrane with a lesion, organism, or debris while performing intra-oral procedures.

Accidental self injury with a contaminated needle, or sharp instruments

InhalationInhalation of microorganisms aerosolized from a patient’s blood or saliva occurs when using high speed or ultrasonic instruments

Universal precautionsUniversal precautions

Universal precautions are a set of precautions designed to prevent transmission of HIV, HBV, and other blood borne pathogens when providing first aid or health care

Under universal precautions, blood and certain body fluids of all patients are considered potentially infectious for HIV, HBV, and other blood borne pathogens

Universal precautions - involve the use of protective barriers such as gloves, gowns, aprons, masks, or protective eye wear

Needles, scalpels, and other sharp instruments or devices

Hand Hygiene & Personal HygieneHand Hygiene & Personal Hygiene

Hands are the most common mode of pathogen transmission

Reduce spread of antimicrobial resistance

Prevent health care-associated infections

Personal HygienePersonal Hygiene

Visibly dirtyAfter touching

contaminated objects with bare hands

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

Personal hygienePersonal hygieneAll dental staff who come into direct

contact with patients should practice meticulous personal hygiene

Fingernails must be kept short and jewellery on the hands and watches should be removed since they tend to trap organisms and may tear the gloves

Hair should be put up tightly

Hand Hygiene DefinitionsHand Hygiene Definitions

Handwashing– Washing hands with plain soap and water

Antiseptic handwash– Washing hands with water and soap or other detergents

containing an antiseptic agent

Alcohol-based handrub– Rubbing hands with an alcohol-containing preparation

Surgical antisepsis– Handwashing with an antiseptic soap or an alcohol-based

handrub before operations by surgical personnel

Barrier techniquesBarrier techniques

The proper use of barrier techniques as part of universal precautions is extremely important

The wearing of gloves, masks, protective eyewear, and clinic attire by all personnel who have direct contact with the patient is required for all treatment, regardless of their nature

Gloves Gloves Surgical glovesExamination glovesUtility gloves: heavy rubber gloves used for

cleaning instruments and environmental surfaces

Gloves can be autoclaved and reused; but they must be discarded if they are cracked, discolored or have punctures, tears or other evidences of deterioration

Aerosols Aerosols

Aerosol is defined as small droplets, usually 50 μm or less in diameter, which can remain suspended in air for some time.

The smaller particles of an aerosol have the potential to penetrate and lodge in the smaller passages of the lungs and are thought to carry the greatest potential for transmitting infections

Diseases such as tuberculosis, influenza, and SARS (Severe Acute Respiratory Syndrome) are known to be spread by droplets or aerosols

Dental handpieces, airotors, air/water syringes, and ultrasonic scalers produce large amounts of aerosols.

The risk of infection from aerosols can be minimized by

Use of protective barriers Pre-procedural rinsing with 0.2% chlorhexidine;

reduces the bacterial count in the aerosols Proper patient positioning Use of saliva ejectors and high volume suctions

Saliva EjectorsSaliva Ejectors

Previously suctioned fluids might be retracted into the patient’s mouth when a seal is created

Do not advise patients to close their lips tightly around the tip of the saliva ejector

HIGH VOLUME EVACUATION (SUCTION)

SALIVA EJECTOR

Biofilms Biofilms Adhesion of bacteria and

other microorganisms to solid surfaces in aqueous environments can result in the formation of a slime-like material called biofilm

Biofilm protects the bacteria from disinfectants and can trap other potentially infective microorganisms

Biofilms can form within dental water lines by two ways

Bacteria may be pulled into the water lines during treatment from the patient’s mouth which may later transmit to other patients

Bacteria present in the main water supply can concentrate in the dental unit water line especially in warm and stagnant conditions

Biofilm formation can be minimized by Independent water reservoirs for the dental

unit Using sterile water Drain and flush water lines for several

minutes before beginning clinic each day After each patient, run high-speed

handpieces and scalers for a minimum of 20-30 seconds to discharge contaminated water and air that may have entered the water line

Dental Unit Waterlines Dental Unit Waterlines and Biofilmand Biofilm

Microbial biofilms form in small bore tubing of dental units

Biofilms serve as a microbial reservoir

Primary source of microorganisms is municipal water supply

Flushing the scalers and handpieces (bleeding) for 30 seconds between each patient can discharge the contaminated water that have entered the water line

Handling of sharp instrumentsHandling of sharp instrumentsCare must be taken while handling needles and

other sharp instruments during and after procedures, while cleaning used instruments, and during disposal of used needles.

Forceps must be used to handle sharp instruments

Disposable needles, scalpel blades and other sharp items should be discarded into puncture-resistant containers that are easily accessible for disposal

When recapping needles, both hands should never be used; instead, a one-handed “scoop technique” or another instrument should be used

Wrong method“scoop technique”

Never touch sterile instruments or other materials like cotton with contaminated gloved hand or used instruments

Sterilized materials and instruments should be handled with a sterilized cheatel forceps, which should be stored with the tip immersed in a disinfectant solution

Handling sterile instruments

Chittle ForcepsChittle Forceps

Anaesthetic SolutionAnaesthetic Solution

Local AnaestheticLocal Anaesthetic

Special ConsiderationsSpecial Considerations Dental handpieces and other

devices attached to air and waterlines

Dental radiology Single-use (disposable)

Devices Preprocedural mouth rinses Oral surgical procedures

Handling biopsy specimens Handling extracted teeth Laser/electrosurgery

plumes or surgical smoke Dental laboratory Mycobacterium

tuberculosis Creutzfeldt-Jacob Disease

(CJD) and other prion-related diseases

Sterilization Sterilization

Process by which all forms of microorganisms including viruses, bacteria, fungi, and spores over articles or surfaces are destroyed

Articles or objects free of living organisms are termed sterile

Methods of sterilizationMethods of sterilization

Moist heat (autoclaving) Dry heat (hot-air oven)Chemicals (chemiclaving)

Most preferred method of sterilizationSteam Under pressure

Recommended sterilization Recommended sterilization cycles for autoclavingcycles for autoclaving

Temperature Time Pressure

Unwrappedinstruments

1340C 3 min 30 psi

Wrappedinstruments

1210C 15-20 min

15 psi

Packaging and sealing of Packaging and sealing of instruments instruments

Instruments should be carefully packaged in functional sets before sterilization.

This packaging protects the instruments after sterilization and before use at chair side

A variety of packaging materials are available

Self-sealing, paper-plastic, peel pouches are the most convenient

Some packaging materials have indicators which change color when sterilization is completed

Boiling Boiling

Immersion of instruments in boiling water does not achieve sterilization as many of the bacterial spores can withstand boiling

Cross infection from contaminated water containing bacterial spores not killed by boiling is also a possibility

Classification of Instruments to Classification of Instruments to be Sterilizedbe Sterilized

Dental instruments are classified into three categories depending on their risk of transmitting infection and the need to sterilize them between use

critical Semi-critical Non-critical

Critical Critical Surgical and other instruments used to penetrate

soft tissue or bone Should be sterilized after each use

Examples are Forceps, periosteal elevators, cross bars Scalpels, scissors, suture needles Bone chisels Surgical burs Scaling instruments Endodontic instruments

Semi-criticalSemi-critical Instruments that do not penetrate soft tissue or

bone but contact oral tissues These instruments should also be sterilized after

each useExamples are Mouth mirrors Burs Handpieces Tweezers Restorative instruments Impression trays

Non-criticalNon-critical Those items, which do not come into contact with

body fluids Have a relatively low risk of transmitting infectionExamples are Medication bottles Light cure tips Glass slab and cement spatula Instrument trays Orthodontic pliers Dapen dish

Surface asepsisSurface asepsis

Use surface barriers to protect clinical contact surfaces, particularly those that are difficult to clean (e.g., switches on dental chairs)

Change surface barriers between patients

Disinfection of Dental Disinfection of Dental EquipmentsEquipments

Clinical contact surfaces and dental equipments that are not covered should be cleaned and disinfected with a hospital level disinfectant (activity against HIV, HBV, and Mycobacterium tuberculosis) after each patient.

Sodium hypochlorite (household bleach) is an effective and economical surface disinfectant

DISINFECTANTS

AntisepticsAntisepticsBiguanides:

ChlorhexidineLow toxicity

– Used on skin and mucous membranes

Clinical Contact SurfacesClinical Contact Surfaces

Housekeeping SurfacesHousekeeping Surfaces

Spray-wipe-spray techniqueSpray-wipe-spray technique Spray the disinfectant

solution on the surface Using a gauze piece, wipe

the surfaces in overlapping strokes

Spray again Allow the disinfectant to dry

on the surface for about 10 minutes

Autoclaving

U V ChamberU V Chamber

Instrument StorageInstrument Storage

Autoclaved TowelAutoclaved Towel

GlovesGloves

Hand DisinfectantsHand Disinfectants

Alcohol Alcohol

Dental Handpieces and Other Devices Dental Handpieces and Other Devices Attached to Air and WaterlinesAttached to Air and Waterlines

Clean and heat sterilize intraoral devices that can be removed from air and waterlines

Follow manufacturer’s instructions for cleaning, lubrication, and sterilization

Do not use liquid germicides or ethylene oxide

Handpiece Disinfection & OilingHandpiece Disinfection & Oiling

Air CompressorAir Compressor

Waste ManagementWaste Management

Sharp InstrumentsSharp Instruments

Dental Chair CareDental Chair Care

ApronApron

Infection Control Program GoalsInfection Control Program Goals

Provide a safe working environment– Reduce health care-associated

infections – Reduce occupational

exposures