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Infection Control in Dental

Health-Care Settings



Sets ³Guidelines for Infection Control in Dental Health-Care

Settings-Core´

Provide an overview of many of the basic principles of

infection control



Infection Control in DentalHealth-Care Settings: An Overview

Background

Personnel Health Elements

Blood borne Pathogens

Hand Hygiene Personal Protective Equipment

Sterilization and Disinfection

Environmental Infection Control

Dental Unit Waterlines

Special Considerations

Program Evaluation



B ACKGROUND

� 1918-1919 - People died more of infections than byaction in war

� 1936 - Penicillin

� 1950 - Eradiation of polio

� 1978 - Eradiation of small pox

� 1981 - Vaccine against HBV

� 1983 - HIV

DHCW -13%-25 %

General population± 5%

Thus, risk for unvaccinated member of dental team ± 2to 5 times more



1978-First ADA Infection Control Guideline

1981- CDC first reports on AIDS infections

1986 ± CDC Recommended Infection Control Practices

1987- CDC Universal Precautions Guidelines

1987 ± OSHA: Protection against occupational exposure to HBV and

HIV

1993 ± CDC - Infection Control practices for Dentistry

2003 ± CDC Guidelines for Infection Control in Dental

Settings

B ACKGROUND



Recommendations

� Improve effectiveness and impact of

public health interventions

� Inform clinicians, public health

practitioners, and the public

� Based on a range of rationale, from

systematic reviews to expert opinions



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 contaminatedinstrument or surface

� Contact of mucosa of the eyes, nose, or mouth with droplets or spatter

� Inhalation of airborne micro-organisms



Chain of InfectionChain of Infection

Pathogen

Source

ModeEntry

Susceptible Host



Standard Precautions

� Apply to all patients

� Integrate and expand UniversalPrecautions to include organismsspread by blood and also

±Body fluids, secretions, and excretions

except sweat, whether or not they containblood

±Non-intact (broken) skin

±Mucous membranes



Elements of StandardPrecautions

� Hand washing

� Use of gloves, masks, eye

protection and gowns� Patient care equipment

� Environmental surfaces

� Injury prevention



Personnel Health Elements of an

Infection Control Program

� Education and training

� Immunizations

� Exposure prevention and postexposuremanagement

� Medical condition management and work-

related illnesses and restrictions� Health record maintenance



Bloodborne Pathogens



Preventing Transmission of

Bloodborne Pathogens

� Are transmissible in health care

settings

� Can produce chronic infection� Are often carried by persons unaware

of their infection

Bloodborne viruses such as hepatitis B virus

(HBV), hepatitis C virus (HCV), and human

immunodeficiency virus (HIV)



Potential Routes of Transmission

of B

loodborne PathogensPatient DHCP

DHCP Patient

Patient Patient



Contaminated instruments

Blood

Airborne infections

Inhalation route

Contact with splatter



Factors Influencing OccupationalRisk of Blood borne Virus Infection

� Frequency of infection among

patients

� Risk of transmission after a blood

exposure (i.e., type of virus)

� Type and frequency of bloodcontact



Average Risk of Bloodborne Virus

Transmission after NeedlestickSource Risk

HBV

HBsAg+ and

HBeAg+

22.0%-31.0% clinical hepatitis;37%-62% serological evidence

of HBV infection

HBsAg+ and

HBeAg-

1.0%-6.0% clinical hepatitis;

23%-37% serological

evidence of HBV infection

HCV 1.8% (0%-7% range)

HIV 0.3% (0.2%-0.5% range)



Concentration of HBV in Body

Fluids

High Moderate Low/Not

Detectable

Blood Semen Urine

Serum Vaginal Fluid Feces

Wound exudates Saliva Sweat

TearsBreast Milk



Hepatitis B Vaccine

Vaccinate all DHCP who are at risk of

exposure to blood

Provide access to qualified health care

professionals for administration and

follow-up testing

Test for anti-HBs 1 to 2 months after 3rd dose



HEPATITIS B

Incubation period 2-6 monthsTransmission route parenteral, percutaneous or mucosal

Clinically ± 66% HBV cases are asymptomatic

- 1% Fulminant Hepatitis

- 33% symptomatic

If Serological markers persists for over 6 months hebecomes a chronic carrier

Treatment: Interferon-3 million units 3 times for 1 weeksuccess rate 30-40%

Vaccine

-Plasma derived vaccine

-Recombinant yeast vaccine



Unvaccinated HBIG X 1 dose Initiate HBV Initiate HBV

(1000-2000 IU I/M ± Adult) vaccine series vaccine series

( 32 ± 48 IU / Kg body wt ± Child)

initiate vaccine series

Vaccine status Antibody response status

Of exposed HCW __________________________________________________________________________________

Source HBsAg +ve Source HBsAg +ve Source unknown /unavailable for test

Previously vaccinated

Known responder No Rx No Rx No Rx

Known non-responder HBIG X 1 dose

initiate re-vac or HBIG X 2 doses

Antibody response Test exposed HCW for anti HBs No Rx Consider re-vac if

Unknown If adequate --- no Rx required known high risk

If inadequate ----- Adm. HBIG X 1 source ( Rx as HbsAg +ve )

and vaccine booster. Test for HBsAg



HCV Infection in

Dental Health Care Settings

� Prevalence of HCV infection

among dentists similar to that of

general population (~ 1%-2%)� No reports of HCV transmission

from infected DHCP to patients or

from patient to patient� Risk of HCV transmission appears

very low



Transmission of HIV from

Infected Dentists to Patients

� Only one documented case of HIV

transmission from an infected

dentist to patients

� No transmissions documented in

the investigation of 63 HIV-infected

HCP (including 33 dentists or

dental students)



Health Care Workers with Documented andPossible Occupationally Acquired HIV/AIDS

CDC Database as of December 2009

* 3 dentists, 1 OMF Surgeon, 2 dental assistants

Documented Possible

Dental Worker 0 6 *

Nurse 24 35

Lab Tech, clinical 16 17

Physician, nonsurgical 6 12

Lab Tech, nonclinical 3 ±

Other 8 69Total 57 139



Seropositivity per 1000

106.83 Maharashtra

177.7 Manipur

50.19 Nagaland

43.7 Punjab

34.2 Pondicherry

15.53 Tamil Nadu

HIV



Risk Factors for HIV Transmission after Percutaneous Exposure to HIV-Infected Blood

� Deep injury

�

Visible blood on device� Needle placed in artery or vein

� Terminal illness in source patient

Source: Cardo, et al., N England J Medicine 1997;337:1485-90.



M ANAGEMENT OF EXPOSURES

TO HIV

� REPORTING OF EXPOSURES ±

a) Date and time of exposure

b) Details of procedure performedc) How the exposure occurred

d) Details of exposure, depth of wound and amount of

blood/fluid in contact

e) Details of exposure source- whether HIV or other bloodborne pathogens



Post Exposure Prophylaxis (PEP)

� Needle-stick injuries & cuts: immersed wash withsoap & water

� Splashes to nose, mouth or skin: flush with plentyof clean water

� Splash/injury to eye: irrigate with water / saline� Do not put injured finger into mouth

� Blood tests(3-5ml) for both immediately ,at 6weeks, 12 weeks and 6 months for HIV,HCV &

HBV� Report immediately to your immediate senior/to authorised medical attendant: it is anemergency!



M ANAGEMENT OF EXPOSURES

TO HIV� SHOULD BE TESTED FOR HIV ANTIBODY TO

ESTABLISH SERO STATUS BEFORE EXPOSURE

� FOLLOW UP TESTING DONE AT 6 ± 12 WEEKS AND

END OF 6 MONTHS TO DETERMINE WHETHER

INFECTION HAS OCCURRED

� B ASED ON RESULTS PEP ADVISED



Determining Exposure Code (EC) of an Injury NACO GUIDELINES

Determining Exposure Code

Is source material / blood / body fluid / instrument soiled by above ?

YES NO No PEP

What Kind of Exposure ?

MM or skin integrity

compromised

Intact skin only Percutaneous exposure ?

VOL ?No PEP

SEVERITY

Few drops,

Short time

Many drops,

Splash, several minutes

Less severe,

Solid needle

More severe,

EC 1 EC 2 EC 2 EC 3



Determining HIV Status Code (SC) of Source NACO GUIDELINES

HIV - ve HIV + ve Status Unknown Source Unknown

No PEP

Low Titer exposure :

Asymptomatic,

Normal CD4

High Titer exposure :

Advanced AIDS,

Low CD4,

High viral load

HIV SC 1 HIV SC 2 HIV SC Unknown



RECOMMENDATION OF PEP REGIMENS B ASED ON

EXPOSURE & STATUS OF SOURCE

NACO GUIDELINES

EC 1 & SC 1 PEP may not be required

EC 1 & SC 2 / EC 2 & SC 1 Basic regimen required

EC 2 & SC 2 Expanded regimen warranted

EC 3 & SC 1 or 2 Expanded regimen warranted

Both EC & SC are not known Basic regimen required

or

EC 2 / EC 3 in absence of SC



Regimens for PEP for HIV

� Basic regimen: Zidovudine(Retrovir, Zidovir, AZT, ZDV) 600mg / day in divided doses

Lamivudine (3TC, Epivir) 150 mgBD X 28 days



Regimens for PEP for HIV

� Expanded regimen: Zidovudine 600 mg/dayin divided doses

Lamivudine 150 mg BD X 28 days +

(Indinavir 800 mg TDS X 28 days

/ Nelfinavir 750 mg TDS X 28 days)

� Side effects of PEP: nausea, vomiting,diarrhoea, fatigue



Risk of HIV,HBV and HCV after

percutaneous exposure

� HIV: 0.3%

� For HCV: approx 3%� For HBV: upto 30% in unvaccinated

individuals (concentration of HBV in

blood may be >10,000,000 infectiousparticles /ml as against 10-100 inf

particles / ml in HIV)



In the event of an exposure:

further advice to HCW

� HCW counseled to report again at intervals of 6 weeks, 12 weeks and 6 months for : Ab to

HIV, anti HCV and HB

sAg� Not to donate blood /internal organ/ semen

� To abstain from sexual intercourse/ usecondom persistently during entire observation

period� In pregnancy: PEP safe after first trimester

� If a lady, to avoid pregnancy duringobservation period & if lactating not to breast-

feed child during observation period



Exposure PreventionStrategies



Engineering Controls

� Isolate or remove the hazard

� Examples:

±Sharps container

±Medical devices with injury

protection features (e.g., self-

sheathing needles)



Work Practice Controls

Change the manner of performing

tasks

Examples include:� Using instruments instead of fingers

to retract or palpate tissue

� One-handed needle recapping



Administrative Controls

� Policies, procedures, and

enforcement measures

� Placement in the hierarchy variesby the problem being addressed

±Placed before engineering controls

for airborne precautions (e.g., TB)



� Wound management

� Exposure reporting

� Assessment of infection risk ±Type and severity of exposure

±Bloodborne status of sourceperson

±Susceptibility of exposed person

Post-exposure Management



Hand Hygiene



Why Is Hand Hygiene Important?

� Hands are the most common

mode of pathogen transmission

� Reduce spread of antimicrobial

resistance

� Prevent health care-associated

infections



Hands Need to be Cleaned

when««««««.

� Visibly dirty

� After touching

contaminated objectswith bare hands

� Before and after patient

treatment (before glove

placement and after

glove removal)



Hand 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



Efficacy of Hand HygienePreparations in Reduction of

Bacteria

Good Better Best

Plain Soap Antimicrobialsoap

Alcohol-basedhandrub

Source: http://www.cdc.gov/handhygiene/materials.htm



Alcohol-based Preparations

� Rapid and

effective

antimicrobialaction

� Improved skin

condition

� More accessible

than sinks

� Cannot be used if

hands are visibly

soiled� Store away from

high temperatures

or flames

� Hand softeners

and glove powders

may ³build-up´

Benefits Limitations

S i l H d H i



Special Hand Hygiene

Considerations

� Use hand lotions to prevent skindryness

� Consider compatibility of hand careproducts with gloves (e.g., mineral oilsand petroleum bases may cause earlyglove failure)

� Keep fingernails short� Avoid artificial nails

� Avoid hand jewelry that may tear gloves



Personal Protective

Equipment



Personal

ProtectiveEquipment

� A major component of StandardPrecautions

� Protects the skin and mucous

membranes from exposure to infectious

materials in spray or spatter

� Should be removed when leaving

treatment areas



Masks, Protective Eyewear, FaceShields

� Wear a surgical mask and either eye

protection with solid side shields or a face

shield to protect mucous membranes of

the eyes, nose, and mouth

� Change masks between patients

� Clean reusable face protection between

patients; if visibly soiled, clean and

disinfect



Protective Clothing

� Wear gowns, lab coats, or uniforms that cover skinand personal clothing likely

to become soiled withblood, saliva, or infectiousmaterial

� Change if visibly soiled

� Remove all barriers beforeleaving the work area



Gloves

� Minimize the risk of health care personnel

acquiring infections from patients

� Prevent microbial flora from being

transmitted from health care personnel topatients

� Reduce contamination of the hands of

health care personnel by microbial flora that

can be transmitted from one patient toanother

� Are not a substitute for handwashing!



Recommendations for Gloving

� Wear gloves when contactwith blood, saliva, andmucous membranes is

possible� Remove gloves after

patient care

� Wear a new pair of glovesfor each patient



Recommendations for Gloving

Remove gloves that

are torn, cut or punctured

Do not wash, disinfector sterilize gloves for reuse



Sterilization and Disinfection

of Patient Care Items

Critical Instruments

Semi-critical Instruments

Non-critical Instruments andDevices



Critical Instruments

� Penetrate mucous membranes or

contact bone, the bloodstream, or

other normally sterile tissues (of the

mouth)

� Heat sterilize between uses or use

sterile single-use, disposable devices

� Examples include surgicalinstruments, scalpel blades,

periodontal scalers, and surgical

dental burs



Instrument Processing Area

� Use a designated processing area to

control quality and ensure safety

� Divide processing area into work areas

± Receiving, cleaning, and

decontamination

± Preparation and packaging

± Sterilization

± Storage



Automated Cleaning

� Ultrasonic cleaner

� Instrumentwasher

� Washer-

disinfector



Manual Cleaning

� Soak until ready to

clean

� Wear heavy-duty

utility gloves, mask,

eyewear, andprotective clothing



Preparation and Packaging

� Critical and semi-critical items thatwill be stored should be wrapped or placed in containers before heat

sterilization� Hinged instruments opened and

unlocked

� Place a chemical indicator inside thepack

� Wear heavy-duty, puncture-resistantutility gloves



Heat-Based Sterilization

� Steam under pressure

(autoclaving)

±Gravity displacement ±Pre-vacuum

� Dry heat

� Unsaturated chemical vapor



Liquid Chemical Sterilant / Disinfectants

� Only for heat-sensitive

critical and semi-critical

devices� Powerful, toxic chemicals

raise safety concerns

� Heat tolerant or disposable alternatives are

available

S



Sterilization MonitoringTypes of Indicators

� Mechanical ±Measure time, temperature, pressure

� Chemical

± Change in color when physical parameter isreached

� Biological (spore tests) ± Use biological spores to assess the

sterilization process directly

B. Steriothermophilus strips

Color coded strips



Environmental Infection

Control



Environmental Surfaces

� May become contaminated

� Not directly involved in infectious

disease transmission� Do not require as stringent

decontamination procedures



Clinical Contact Surfaces

Clinical contact

surfaces

High potential for

direct contamination

from spray or spatter

or by contact withDHCP¶s gloved hand

H k i S f



Housekeeping Surfaces

Housekeeping

surfaces

Do not come intocontact with

patients or devices

Limited risk of

disease

transmission

General Cleaning



General Cleaning

Recommendations

� Use barrier precautions

� Physical removal of microorganisms bycleaning is as important as the disinfection

process

� Follow manufacturer¶s instructions for proper use hospital disinfectants



Medical Waste

� Medical Waste: Not considered

infectious, thus can be discarded in

regular trash

� Regulated Medical Waste:Poses a potential risk of infection

during handling and disposal

Regulated Medical Waste



Regulated Medical Waste

Management

� Properly labeled containment

to prevent injuries and leakage

� Medical wastes are ³treated´ in

accordance with state and

local EPA regulations

� Processes for regulated waste

include autoclaving andincineration



WASTE CATEGORIES

1. Human anatomical waste

2. Microbiology/ biotechnology waste

3. Soiled waste

4. Waste sharps

5. Liquid waste

6. Discarded medicines and cytotoxic

drugs7. Incineration ash

8. Chemical waste

WASTE MANAGEMENT



W ASTE M ANAGEMENT

Yellow BOD Y PARTS

Incineration & deep burial

Red SOILED WASTE

Autoclaving, Microwaving, Chemical

Blue SHARPS

White Autoclaving, Microwaving, Chemicaldestruction & shredding

Black LIQUID WASTE

Green Disposal in secure landfill



Dental Unit Waterlines,

Biofilm,

and Water Quality

D t l U it W t li



Dental Unit Waterlines

and Biofilm

� Microbial biofilms form

in small bore tubing of

dental units

� Biofilms serve as a

microbial reservoir

� Primary source of

microorganisms ismunicipal water

supply

D t l U it W t Q lit



Dental Unit Water Quality

� Using water of uncertain quality is

inconsistent with infection control

principles

� Colony counts in water from untreated

systems can exceed 1,000,000

CFU/mL

CFU=colony forming unit

� Untreated dental units cannot reliably

produce water that meets drinking

water standards

A il bl DUWL T h l



Available DUWL Technology

� Independent reservoirs

� Chemical treatment

� Filtration� Combinations

� Sterile water delivery systems

St il I i ti S l ti



Sterile Irrigating Solutions

� Use sterile saline or sterile

water as a coolant/irrigator

when performing surgicalprocedures

� Use devices designed for

the delivery of sterileirrigating fluids



Dental Handpieces and Other Devices

Attached to Air and Waterlines

� Clean and heat sterilize intraoraldevices 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

Components of Devices Permanently



Components of Devices Permanently

Attached to Air and Waterlines

� Do not enter patient¶s mouth butmay become contaminated

� Use barriers and changebetween uses

� Clean and intermediate-level

disinfect the surface of devices if visibly contaminated



Saliva 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 thesaliva ejector

D t l R di l



Dental Radiology

� Wear gloves and other appropriate

personal protective equipment as

necessary

� Heat sterilize heat-tolerantradiographic accessories

� Transport and handle exposed

radiographs so that they will notbecome contaminated

� Avoid contamination of developing

equipment



Precautions for ParenteralMedications

� IV tubings, bags,connections, needles, andsyringes are single-use,

disposable� Single dose vials

±Do not administer tomultiple patients even if

the needle on the syringeis changed

±Do not combine leftover contents for later use



Single-Use (Disposable) Devices

� Intended for use on one patient during a

single procedure

� Usually not heat-tolerant� Cannot be reliably cleaned

� Examples: Syringe needles, prophylaxis

cups, and plastic orthodontic brackets

P d l M th Ri



Pre-procedural Mouth Rinses

� Antimicrobial mouth rinses prior to a

dental procedure

±Reduce number of microorganisms inaerosols/spatter

±Decrease the number of microorganisms

introduced into the bloodstream

� Unresolved issue±no evidence that

infections are prevented

O l S i l P d



Oral Surgical Procedures

� Present a risk for microorganisms toenter the body

� Involve the incision, excision, or reflection of tissue that exposesnormally sterile areas of the oral cavity



Precautions for Surgical Procedures

Sterile IrrigatingSolutions

Sterile Surgeon¶sGloves

Surgical

Scrub



Handling Biopsy Specimens

� Place biopsy in sturdy,

leakproof container

� Avoid contaminating

the outside of the

container

� Label with a biohazard

symbol

E t t d T th



� Considered regulatedmedical waste

±Do not incinerate extracted teeth

containing amalgam ±Clean and disinfect before

sending to lab for shadecomparison

� Can be given back topatient

Extracted Teeth

Handling Extracted Teeth



Handling Extracted Teeth

in Educational Settings

� Remove visible blood and debris

� Maintain hydration

� Autoclave (teeth with no

amalgam)

�

Use Standard Precautions

Laser/Electrosurgery Plumes and



Laser/Electrosurgery Plumes and

Surgical Smoke

� Destruction of tissue creates smoke

that may contain harmful by-products

�

Infectious materials (HSV, HPV) maycontact mucous membranes of nose

� No evidence of HIV/HBV transmission

� Need further studies



Disinfection in Dental Laboratories

Receiving area Disinfection area

Cleaning

DisinfectionWorking area

Recommended methods of



Recommended methods of

decontamination

Alginate, Zinc oxide eugenol paste, Zinc

oxide, eugenol paste, Stone casts ±

0.1% Sodium hypochlorite

Dentures, Wax bite block or Wafer-

Immerse in 0.1 % Sodium Hypochlorite

DENTAL LABORATORY



DENTAL LABORATORY

� All disinfection procedures are

accomplished prior to delivery to lab ± Done in dental operatory or professional work

area

�³O

nly Biologically Clean Items Permitted´ � Incoming :

1. Rinse under running tap water toremove blood/saliva

2. Disinfect as appropriate

3. Rinse thoroughly with tap water toremove residual disinfectant



Outgoing :

1. Clean and disinfect before

delivery to patient

2. After disinfection: rinse and

place in plastic bag with diluted

mouthwash until insertion

3. Do not store in disinfectant

before insertion

Metals



Metals

� Heat sterilize all metal and heat-stableinstruments that contact oral tissues,contaminated appliances, or potentiallycontaminated appliances should be heatsterilized after each use ± Facebow fork, metal impression trays, burs,

polishing points, rag wheels, laboratory knives

� For porcelain restorations that arecharacterized intraorally

± Take them directly to porcelainfurnace

± Sintering process sterilizesrestoration

SO G S



PERSONAL HYGIENE IN LABS

� Refrain from the following activities while in the

lab where there is potential for occupational

exposure:

± Eating ± Drinking

± Smoking

± Applying cosmetics or lip balm

± Handling contact lenses

I f ti C t l P G l



Infection Control Program Goals

� Provide a safe

working environment

±Reduce health care-associated infections

±Reduce occupational

exposures

Program Evaluation



Program Evaluation

� Strategies and Tools

± Periodic observational

assessments

± Checklists to documentprocedures

± Routine review of

occupational exposures

to bloodbornepathogens



³P rogram evaluation providesan opportunity to identify and

change inappropriate

practices, thereby improving

the effectiveness of your

infection control program.´



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