Infection control in dentistry / /certified fixed orthodontic courses by Indian dental academy

INFECTION CONTROL IN
DENTISTRY

INDIAN DENTAL ACADEMY
Leader in Continuing Dental Education
www.indiandentalacademy.com


CONTENTS
 INTRODUCTION
 HISTORY
 TRANSMISSION OF INFECTION IN DENTAL
OPERATORY
 IMPACT OF HEPATITIS B & HIV
 SUMMARY OF CURRENT OSHA
REGULATION
 OBJECTIVES OF INFECTION CONTROL
 PATIENT SCREENING
 PERSONAL BARRIER PROTECTION
 EMERGENCY & EXPOSURE INCIDENT
PLAN

 OPERATORY ASEPSIS
 CLINICAL WASTE DISPOSAL
 INSTRUMENT HANDLING & CLEANING
 STEAM PRESSURE STERILIZATION
 CHEMICAL VAPOR PRESSURE
STERIIZATION
 DRY HEAT STERILIZATION
 MONITORS OF STERILIZATON
 HANDPIECE ASEPSIS
 GUIDELINES FOR STERILIZATION OF
ENDODONTIC INSTRUMENTS
 CONCLUSION.

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.
 EXPOSURE – is defined as specific eye, mouth,
other mucous membrane, non intact skin, or
parenteral contact with blood or other potentially
infectious materials.


 UNIVERAL PRECAUTIONS - means that all
patients and blood contaminated body fluids are
treated as infectious.
 WORK PRACTICE AND ENGINEERING
CONTROLS – are terms that describe
precautions(e.g; careful handling of sharps) and
use of devices to reduce contamination risks(high
volume suction)


 PERSONAL PROTECTIVE EQUIPMENT
(PPE) – is a term used for barriers, such as
gloves, gown, or mask.
 HOUSEKEEPING – is a term that relates to
cleanup of treatment-soiled operatory equipment,
instruments, counters, and floors, as well as to
management of used gowns and waste.


 STERILIZATION: Use of a physical or
chemical procedure to destroy all microorganisms
including substantial numbers of resistant
bacterial spores.
 STERILE: Free from all living microorganisms;
usually described as a probability (e.g., the
probability of a surviving microorganism being 1
in 1 million).


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

 GERMICIDE: An agent that destroys
microorganisms, especially pathogenic
organisms. Terms with the same suffix (e.g.,
virucide, fungicide, bactericide, tuberculocide,
and sporicide) indicate agents that destroy the
specific microorganism identified by the prefix.
Germicides can be used to inactivate
microorganisms in or on living tissue (i.e.,
antiseptics) or on environmental surfaces (i.e.,
disinfectants).

TRANSMISSION OF
INFECTION
 Infection transmission during dental procedures
is dependent on four factors:
1. Source of infection – may be a patient or a
member of the dental team who is suffering
from, or is a carrier of, an infectious disease.
SOURCE

Patients suffering Patients in carriers
from acute www.indiandentalacademy.com
prodromal known unknown
infection stage

2. Means of transmission – Micro organisms
capable of causing disease are present in human
blood and saliva.Contact with blood or saliva
may transmit such pathogenic organisms causing
infection.
3. Route of transmission – Transmission may occur
due to inhalation or inoculation.
4. Susceptible host – Is a person who lacks
effective resistance to a particular micro
organism. E.g immunocompromised patients,
pregnantwww.indiandentalacademy.com
women and children.

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

Infection through any of these routes requires that all
of the following conditions be present:
 An adequate number of pathogens, or disease-
causing organisms, to cause disease.
 A reservoir or source that allows the pathogen to
survive and multiply (e.g., blood).
 A mode of transmission from the source to the
host.
 An entrance through which the pathogen may
enter the host.
 A susceptible host (i.e., one who is not immune).

INFECTIONS OF CONCERN IN
DENTISTRY
TRANSMITTED BY INHALATION
Varicella virus Chicken pox
Paramyxovirus Measles & mumps
Rhino/ adeno virus Common cold
Rubella German measles
Mycobacterium Tuberculosis
Candida sp. Candidosis.

TRANSMITTED BY INOCULATION
Hepatitis B,C,D Hepatitis B, hep C,
virus Hepatitis D
Herpes simplex I Oral herpes,
herpetic whitlow
Herpes simplex II Genital herpes
HIV AIDS & ARC
Neisseria Gonorrhea
gonorrhoeae
Treponema Syphilis
pallidum
S.aureus/albus Wound abscesses

IMPACT OF HEPATITIS B
 Hepatitis B was first to gain attention as an
infection risk for all health care personnel who
have blood and body fluid contact.
 Infection can occur by –
A. Percutaneous inoculation – contaminated
needles, spatter of blood or blood contaminated
saliva on broken skin.
B. Non- percutaneous infection via intact barriers –
contaminated fluids in contact with mucous
membranes of eyes and mouth.

C. Indirect transmission – the environment is
regarded as contaminated after treatment of an
HBV positive patient, since HBV is very stable
outside the body.


INFECTION RISKS FOR
PERSONNEL FROM HBV
 One in three parenteral exposures of personnel to
HB-infected blood has caused hepatitis B
infection.
 Thus, of 300 persons parenterally exposed, 100
will be infected , instead of 1 person in 250 to
300 infected when exposed to HIV.
 With a 2% death probability, 2 of the 100 HBV
exposed person may die compared with 1 HIV
infected exposed person.

 Thus, a parenteral blood exposure of a
nonimmune person to HBV carries at least 2
times the mortality risk of a similar HIV
exposure.
 In studies of personnel who sustained injuries
from needles contaminated with blood containing
HBV, the risk of developing clinical hepatitis if
the blood was positive for both HBsAg and
HBeAg was 22%--31%; the risk of developing
serologic evidence of HBV infection was 37%--
62%.

 By comparison, the risk of developing clinical
hepatitis from a needle contaminated with
HBsAg-positive, HBeAg-negative blood was
1%--6%, and the risk of developing serologic
evidence of HBV infection, 23%--37%.
 With the advent of vaccine, mortality rates may
approach zero.


SEROLOGICAL TESTS
 Testing for HBsAg is determines presence of
infected persons whether they are symptomatic or
not.
 Testing for HBeAg determines presence of an HB
antigen in blood when Hb virus concentrations
are high and relate to ability to infect others.
 Testing for anti-HBc – a marker for prevoius HB
infection.


 Testing for anti-HBs determines the presence of
antibodies that can protect against future HB
infection. Detection of anti-HBs means that the
person is infected and recovered or has been
immunised with a vaccine.


IMMUNIZATION
 Passive immunization may be employed
following any acute exposure with human serum
immune globulin.
 Active immunization with two new genetically
engineered vaccines derived from bread yeast,
Engerix-B and Recombivax B is given.
 Vaccination requires one dose followed with
another 1 month later and third dose 6 months
later.

 Health care personnel should be tested for anti-
HBs 1--2 months after completion of the 3-dose
vaccination series .
 Those who do not develop an adequate antibody
response (i.e., anti-HBs <10 mIU/mL) to the
primary vaccine series should complete a second
3-dose vaccine series or be evaluated to
determine if they are HBsAg-positive.


 Health care professionals can test their blood with
radioimmunoassay for anti-HBs to check
immunity after 3 years.
 If the test results are below 10 serum ratio units, a
booster dose can be taken.


IMPACT OF HIV
 The risk of HIV transmission in dental settings is
extremely low.
 Prospective studies worldwide indicate the
average risk of HIV infection after a single
percutaneous exposure to HIV-infected blood is
0.3% (range: 0.2%--0.5%) . After an exposure of
mucous membranes in the eye, nose, or mouth,
the risk is approximately 0.1%.


 Laboratory studies have determined if needles
that pass through latex gloves are solid rather
than hollow-bore, or are of small gauge (e.g.,
anesthetic needles commonly used in dentistry),
they transfer less blood.
 In a retrospective case-control study, an increased
risk for HIV infection was associated with
exposure to a relatively large volume of blood, as
indicated by a deep injury, or a procedure that
involved a needle placed in a vein or artery.
 The risk was also increased if the exposure was to
blood from patients with terminal illnesses,
possibly reflecting the higher titer of HIV in late-
stage AIDS.www.indiandentalacademy.com

 In dried infected blood, 99% of HIV becomes
inactive in about 90 mins.
 When kept wet, the virus may survive for 2 or
more days.
 HIV is killed by all methods of sterilization.
When used properly, all disinfectants except
some quarternary ammonium compounds are said
to inactivate HIV in less than 2 minutes.


SEROLOGY OF HIV
INFECTION
 HIV infection is detected by blood tests (enzyme-
linked immunoassay [EIA], Western Blot, and
fluorescent antibody tests) that detect antibodies
formed against the virus.
 Tests for anti HIV antibody are often positive
within 3 months after infection; most are positive
by 6 months; 1% take up to 12 months to become
positive.
 A second positive test is necessary to confirm
positive serologies.

FEDERAL OCCUPATIONAL
SAFETY & HEALTH
ADMINISTRATION (OSHA)
 The OSHA rule derives from the original
Occupational Safety and Health Act passed by
the U.S. Congress in 1970.
 The Act created the Occupational Safety and
Health Agency (OSHA) in the U.S. Department
of Labor .


 The Act covers two regulated programs of
compliance:
 (1) an OSHA Hazard Communications program
concerning risks from environmental and
chemical hazards in the workplace.
 (2) an OSHA bloodborne Pathogens, program
that addresses control of "occupational exposure
to blood and other potentially infectious
materials.”


SUMMARY OF THE CURRENT
OSHA REGULATIONS
 Universal precautions must be observed to
prevent contact with blood and other potentially
infectious materials. Saliva is considered a blood-
contaminated body fluid in relation to dental
treatments.
 Engineering controls must be implemented to
reduce production of contaminated spatter, mists,
and aerosols. Examples are use of a rubber dam,
high-volume suction.

 Work practice control precautions must be
implemented to minimize splashing, spatter, or
contact of bare hands with contaminated surfaces.
 Needles must not be bent or cut. When it can be
shown necessary, needles may be resheathed with
mechanical aids or other one-handed techniques.
 Flush eye or mucosa immediately or as soon as
feasible after any contact with blood or
potentially infectious materials.
 Disposal of single-use needles, wires, carpules
and sharps as close to the place of use as possible,
as soon as feasible, in hard-walled, leakproof
containers that are closable from which needles
cannot bewww.indiandentalacademy.com
easily spilled.

 Containers must be red or bear a biohazard label
and must be kept upright and closed when moved.
 Teeth must not be discarded into trash but can be
given to the patient or discarded into sharps
containers.
 Place blood and contaminated specimens (e.g.,
impressions that have not been well-cleaned and
well-disinfected, teeth, biopsy specimens, blood
specimens, and culture specimens) to be shipped,
transported, or stored into suitable closed
containers that prevent leakage.


 Attend to housekeeping requirements including
floors, countertops, sinks, and other
environmental equipment that are subject to
contamination.
 Also included are the use of protective covers that
are changed after each appointment, or
thoroughly clean and disinfect contaminated
surfaces and operatory equipment items that
cannot be covered, discarded, or removed and
sterilized.


 For OSHA purposes in dentistry, regulated waste
also means: (1) liquid or semiliquid blood or
other potentially infectious materials, (2)
contaminated items that would release blood or
other potentially infectious materials in a liquid
or semiliquid state if compressed, and (3) items
that are caked with blood or other potentially
infectious materials and are capable of releasing
these materials during handling.
 Properly dispose of such regulated waste in bio
hazard labeled or red closable bags or other
labeled containers that prevent leakage

OBJECTIVES OF INFCTION
CONTROL
 To protect the patient and members of the dental
team from contracting infections during dental
procedures
 To reduce the numbers of pathogenic micro-
organisms in the dental operatory to the lowest
possible level.
 To implement a high standard of infection control
when treating every patient (universal
precautions)
 To simplify infection control, thus allowing the
dental team to complete treatment with minimal
inconvenience.

STRATEGY TO ACHIEVE
INFECTION CONTROL
 All patients must be screened.
 Barriers for personal protection.
 Careful aseptic techniques.
 Sterilization & disinfection.
 Disposal of contaminated waste safely.
 Laboratory asepsis.


PATIENT SCREENING
 All patients must be screened. A thorough
medical history must be taken.
 Medical history serves several purposes:
1. To detect any unrecognized illness that requires
medical diagnosis and care.
2. To identify any infection or high risk that may
be important to a clinical person exposed during
examination, treatment, or cleanup procedures.
3. To assist in managing and caring for infected
patients www.indiandentalacademy.com

4. To reinforce use of adequate infection control,
bearing in mind that general history taking is not
capable of detecting all infectious persons.


PERSONAL BARRIER
PROTECTION
 Personal protective equipment (PPE), or barrier
precautions, are a major component of Standard
precautions.
 Use of rotary dental and surgical instruments, air-
water syringes creates a visible spray that
contains primarily large-particle droplets of
water, saliva, blood, microorganisms, and other
debris


 This spatter travels only a short distance and
settles out quickly, landing either on the floor,
operatory surfaces, dental health care personnel
(DHCP), or the patient.
 PPE is essential to protect the skin and the
mucous membranes of DHCP from exposure to
infectious or potentially infectious materials.
 PPE should be worn whenever there is potential
for contact with spray or spatter and should be
removed when leaving treatment areas.
 The various barriers are gloves, masks, protective
eye wear, surgical head cap & overgarments.

GLOVES
 All clinical personnel must wear treatment
gloves during all procedures.
 Types:
1. Latex gloves
2. Vinyl gloves
3. Nitile gloves
4. General purpose utility gloves
 Latex gloves are the preferred operatory gloves.
 Gloves manufactured by DOUBLE DIP process
are better than single dip because they have less
pinholes www.indiandentalacademy.com
& use less irritating catalyzing
coagulants.

 Gloves powdered using cornstarch or
cetylpyridium chloride is better than talcum
powder (mineral) which may cause irritation.
 Medical gloves, both patient examination and
surgeon's gloves, are manufactured as single-use
disposable items that should be used for only one
patient, then discarded.
 Gloves should be changed between patients and
when torn or punctured.
 Gloves must have < than 4% leak detectable by a
water test.( FDA regulation).

GLOVE INTEGRITY
 Patient examination and surgeon's gloves
commonly contact multiple types of chemicals
and materials (e.g., disinfectants, composite
resins, and bonding agents) that can compromise
the integrity of latex as well as vinyl, nitrile, and
other synthetic glove materials.
 Latex gloves can interfere with the setting of
vinyl polysiloxane impression materials, although
the setting is apparently not adversely affected by
synthetic vinyl gloves.

 Given the diverse selection of dental materials on
the market, dental practitioners should consult
glove manufacturers regarding the chemical
compatibility of glove materials.
 Washing latex gloves with plain soap,
chlorhexidine, or alcohol can lead to the
formation of glove micropunctures.
 Because this condition, known as WICKING,
can allow penetration of liquids through
undetected holes, washing gloves is not
recommended.


 After a hand rub with alcohol, the hands should
be thoroughly dried before gloving, because
hands still wet with an alcohol-based hand
hygiene product can increase the risk of glove
perforation.
 The effectiveness of wearing two pairs of gloves
in preventing disease transmission has not been
demonstrated, but there is a lower frequency of
inner glove perforation and visible blood on the
hands when double gloves are worn.
 Additional protection might also be provided by
specialty products (e.g., orthopedic surgical
gloves and glove liners)

 Natural rubber latex proteins responsible for latex
allergy are attached to glove powder.
 Allergic patients and DHCP can experience
cutaneous, respiratory, and conjunctival
symptoms related to latex protein exposure.
 Nonlatex (e.g., nitrile or vinyl) powder-free and
low-protein gloves can be used in these cases.
 While cleaning sharp instruments, puncture
resistant utility gloves should be used.
 Nitrile latex gloves are preferred as they cam be
washed & autoclaved.

HAND WASHING
 Removes debris, blood and potentially transient
micro-organisms from the hands & suppress
overgrowth of skin bacteria.
 Hand hygiene (e.g., handwashing, hand
antisepsis, or surgical hand antisepsisis
considered the single most critical measure for
reducing the risk of transmitting organisms to
patients and health care professionals.
 The microbial flora of the skin, first described in
1938, consist of transient and resident
microorganisms . Transient flora, which colonize
the superficial layers of the skin, are easier to
remove by routine handwashing.

 They are often acquired by HCP during direct
contact with patients or contaminated
environmental surfaces; these organisms are most
frequently associated with health-care--associated
infections.
 Resident flora attached to deeper layers of the
skin are more resistant to removal and less likely
to be associated with such infections.
 For routine dental examinations and nonsurgical
procedures, handwashing and hand antisepsis is
achieved by using either a plain or antimicrobial
soap and water

 The purpose of surgical hand antisepsis is to
eliminate transient flora and reduce resident flora
for the duration of a procedure to prevent
introduction of organisms in the operative wound,
if gloves become punctured or torn.
 Skin bacteria can rapidly multiply under surgical
gloves if hands are washed with soap that is not
antimicrobial . Thus, an antimicrobial soap or
alcohol hand rub with persistent activity should
be used before surgical procedures.


 Agents used for surgical hand antisepsis should
substantially reduce microorganisms on intact
skin, contain a nonirritating antimicrobial
preparation, have a broad spectrum of activity, be
fast-acting, and have a persistent effect.
 Persistence (i.e., extended antimicrobial activity
that prevents or inhibits survival of
microorganisms after the product is applied) is
critical because microorganisms can colonize on
hands in the moist environment underneath
gloves.

 At the beginning of a routine treatment period,
watches and jewelry must be removed and hands
must be washed with a suitable cleanser.
 Hands must be lathered for at least 10 seconds,
rubbing all surfaces and rinsed.
 Clean brushes can be used to scrub under and
around the nails.
 Must be repeated at least once to remove all soil.
 Factors that can influence the effectiveness of the
surgical hand antisepsis in addition to the choice
of antiseptic agent include duration and technique
of scrubbing, as well as condition of the hands,
and techniques used for drying and gloving.

METHOD AGENT PURPOSE TIME INDICATI
(min) ON
Routine Water & plain Remove soil 15 sec Before &
handwash soap & transient after treating
microbes each pt.
After bare
Antiseptic Water & Remove/destr 15 sec handed
handwash antimicrobial oy transient touching of
soap microbes & objects
reduce contaminate
resident flora d by blood
Antiseptic Alcohol based Remove/destr Rub or saliva.
hand rub hand rub oy transient hands till When
microbes & dry. visibly
reduce soiled.
resident flora

METHOD AGENT PURPOSE TIME INDICATION
Surgical Water & Remove/de 2- 6 Before
antisepsis antimicrobial stroy mins donning
soap transient sterile
microbes surgeon’s
& reduce gloves for
Water &
resident surgical
plain soap
followed by flora procedures.
alcohol hand (persistent
effect)
rub with
persistent
activity.


HAND CLEANSERS
 CHLORHEXIDINE BASED – these contain 2-
4% chlorhexidine gluconate with 4% isopropyl
alcohol in a detergent solution with a pH of 5.0 to
6.5. They have broader activity for special
cleansing(e.g: for surgery, glove leaks, or when
clincian experiences injury). But it can be
hazardous to eyes.
 POVIDONE IODONE – contain 7.5-10%
povidone iodine, uesd as a surgical handscrub.


 PARACHLOROMETEXYLENOL(PCMX) –
they are bactericidal and fungicidal at 2%
concentration. Non irritating and recommended
for routine use.
 ALCOHOL HAND RUBS- ethyl alcohol and
isopropyl alcohol are widely used at 70%
concentration. They rapidly germicidal when
applied to the skin..


MASKS
 Masks protect the face from splatter and prevent
inhalation of aerosols.
 Aerosols are airborne debris, smaller than 5ųm in
dia, that remain suspended in air.
 Splatter are larger blood contaminated droplets
which may contain sharp debris.
 A mask should have a bacterial filtration
efficiency of 95% or more.
 It should have a close fit around the entire
periphery.

 Masks with highest filtration are rectangular
folded types.
 Dome shaped masks are adequate barriers against
spatter but not against respiratory viruses.
 The mask's outer surface can become
contaminated with infectious droplets from spray
of oral fluids or from touching the mask with
contaminated fingers.
 Also, when a mask becomes wet from exhaled
moist air, the resistance to airflow through the
mask increases, causing more airflow to pass
around edges of the mask.

 When airborne infection isolation precautions are
necessary (e.g., for TB patients), a National
Institute for Occupational Safety and Health
(NIOSH)-certified particulate-filter respirator
(e.g., N95, N99, or N100) should be used.
 N95 refers to the ability to filter 1-µm particles in
the unloaded state with a filter efficiency of
>95% (i.e., filter leakage <5%), given flow rates
of <50 L/min (i.e., approximate maximum airflow
rate during breathing).

 Available data indicate infectious droplet nuclei
measure 1--5 µm; therefore, respirators used in
health-care settings should be able to efficiently
filter the smallest particles in this range.
 Face shields are appropriate for heavy spatter but
should not be used without a mask.
 A new surgical mask has to be used for each
patient.
 Mask must be changed every hour or sooner if it
becomes wet.
 Masks must be discarded after the patient is
dismissed.

 Masks must be removed by grasping only the
string or band at the sides or back of the head.
 Personnel must also protect their hair with a
surgical cap when encountering heavy spatter.
 Appropriate work practices, including use of
dental dams and high-velocity air evacuation,
should minimize dissemination of droplets,
spatter, and aerosols.


PROTECTIVE EYEWEAR
 CAUSES OF EYE DAMAGE:
 Aerosols and spatter may transmit infection
 Sharp debris projected from mouth while using
air turbine handpiece, ultrasonic scaler may cause
eye injury.
 Injuries to eyes of patients caused by sharp
instruments especially in supine position.
 Therefore both the clinician and patients use
protective eyewear.

 Protective eyewear consists of glasses with solid
eyeshields.
 Eyewear must be put on with clean hands before
gloving and must be removed after gloves are
removed.
 Eyewear and shields must be cleaned and
disinfected with water based disinfectant that is
allowed to stand for 5 mins.
 Next it must be washed allowed to soak in 1:50 to
1:100 solution of 5% hypochlorite bleach and is
rinsed and dried.

PROTECTIVE
OVERGARMENTS
 Protective clothing (e.g., gowns, lab coats) should
be worn to prevent contamination of street
clothing and to protect the skin of clinician from
exposures to blood and body substances.
 OSHA bloodborne pathogens standard requires
sleeves to be long enough to protect the forearms
when the gown is worn (i.e., when spatter and
spray of blood, saliva to the forearms is
anticipated).

 A simple, lightweight garment that covers the
arms and chest up to the neck as well as the lap
when seated appears to provide adequate
protection.
 Overgarments must be changed whenever
becoming moist or visibly soiled.


PRECAUTIONS TO AVOID
INJURY EXPOSURE
 Engineering controls are the primary method to
reduce exposures to blood from sharp instruments
and needles. Work-practice controls establish
practices to protect DHCP whose responsibilities
include handling, using, assembling, or
processing sharp devices.
 Needles are a substantial source of percutaneous
injury in dental practice, and engineering and
work-practice controls for needle handling are of
particular importance

 Work-practice controls for needles and other
sharps include placing them in appropriate
puncture-resistant containers located as close as
feasible to where the items were used.
 Sharp end of instruments must be pointed away
from the hand
 Avoid handling large number of sharp hands
 Work-practice controls include removing burs
before disassembling the handpiece from the
dental unit, restricting use of fingers in tissue
retraction or palpation during suturing and
administration of anesthesia, and minimizing
uncontrolled movements of sharp instruments

 Used needles should never be recapped or
otherwise manipulated by using both hands, or
any other technique that involves directing the
point of a needle toward any part of the body.
 A one-handed scoop technique, a mechanical
device designed for holding the needle cap to
facilitate one-handed recapping, or an engineered
sharps injury protection device (e.g., needles with
resheathing mechanisms) should be employed for
recapping needles between uses and before
disposal

 DHCP should never bend or break needles before
disposal because this practice requires
unnecessary manipulation.
 For procedures involving multiple injections with
a single needle, the practitioner should recap the
needle between injections by using a one-handed
technique or use a device with a needle-
resheathing mechanism.


EMERGENCY & EXPOSURE
INCIDENT PLAN
 Management of exposure includes:
A. General wound care and cleaning
B. Counseling of the exposed worker regarding
bloodborne pathogens
C. Source patient testing for HBV,HCV and HIV
(consent required).
D. Documentation of the incident and review
E. Postexposure assessment and prophylaxis for the
health care worker
F. Baseline and follow up serology of the worker.

HBV POSTEXPOSURE
MANAGEMENT
IF AND THEN
Source pt is Exposed worker not Worker should receive
+ve for vaccinated vaccine series
HBsAG  should receive single
dose of HB
immunoglobulin within 7
days.
Exposed worker has Should be tested for anti-
been vaccinated HBs & given 1 dose of
vaccine & 1 dose of HBIG
if < 10 IU

IF AND THEN
Source pt Exposed worker Worker should be encouraged to
is –ve for not vaccinated receive hepatitis B vaccine.
HBsAg
Exposed worker No further action is needed.
has been
vaccinated
Source pt Exposed worker Should receive HB series
refuses not vaccinated HBIG should be considered
testing or
not
identified Exposed worker Management should be
has been individualized.
vaccinated

HIV POSTEXPOSURE
MANAGEMNT
IF THEN AND
Source pt has Exposed worker should Exposed worker
AIDS be counseled about risk of testing –ve
infection. initially should
OR
Should be tested for HIV be retested 6
Source pt is weeks, 12
HIV+ve infection immediately
weeks & 6
Should be advised to seek
OR months after
medical advice for any exposure.
Source Pt refuses febrile illness within12
to be tested weeks
Refrain from blood
donation & take
appropriate precautions

IF THEN AND
Source pt is tested Baseline
& found -ve testing of the
exposed
worker with
follow up
testing 12
weeks later

Source cannot be Serological
identified testing must be
done &
decisions must
be
individualized

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. 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 DHCP or
patients.

 Transfer of microorganisms from contaminated
environmental surfaces to patients occurs
primarily through DHCP hand contact.
 When these surfaces are touched, microbial
agents can be transferred to instruments, other
environmental surfaces, or to the nose, mouth, or
eyes of workers or patients.
 Although hand hygiene is key to minimizing this
transferal, barrier protection or cleaning and
disinfecting of environmental surfaces also
protects against health-care--associated
infections.

 Strategies for cleaning and disinfecting surfaces
in patient-care areas should consider the
1) potential for direct patient contact;
2) degree and frequency of hand contact; and
3) potential contamination of the surface with
body substances or environmental sources of
microorganisms (e.g., soil, dust, or water)


 Almost 40 years ago, Dr. E. H. Spaulding
proposed a classification system for disinfecting
and sterilizing medical and surgical instruments.
This system, or variations of it, has been used in
infection control recommendations and guidelines
over the years.
 According to the CDC, patient-care items (eg,
dental instruments, devices, and equipment) are
categorized as critical, semicritical, or noncritical,
based on the potential risk of transmitting
infection if the item becomes contaminated
during use.

 Instruments that contact cut tissues or penetrate
tissues are considered to be critical items that
require thorough cleaning and sterilization for
reuse. E.g dental burs, endodontic files etc.
 Semicritical items that touch mucosa are the
air/water syringe tip, suction tips, prophy angle,
and handpieces. Others (air/water syringe handle
etc) are handled or touched interchangeably with
treatment instruments that become contaminated
with blood and saliva.


 Semicritical items must be removed for cleaning
and sterilization unless they are either disposable
or can be protected from contamination with
disposable plastic covers.
 Noncritical items are environmental surfaces
such as chairs, benches, floors, walls, and
supporting equipment of the dental unit that are
not ordinarily touched during treatments.
 Contaminated noncritical items require cleaning
and disinfection.


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.
 There is no such thing as a “one-step
disinfectant” The disinfectant step must always
be preceded by cleaning.

 The ideal disinfectant has the following
properties:
 Broad spectrum of activity
 Acts rapidly
 Non corrosive
 Environment friendly
 Is free of volatile organic compounds
 Nontoxic & nonstaining


 High-level disinfection: Disinfection process that
inactivates vegetative bacteria, mycobacteria,
fungi, and viruses but not necessarily high
numbers of bacterial spores. FDA further defines
a high-level disinfectant as a sterilant used for a
shorter contact time.
 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.

 Low-level disinfectant: Liquid chemical
germicide registered with EPA as a hospital
disinfectant. OSHA requires low-level hospital
disinfectants also to have a label claim for
potency against HIV and HBV if used for
disinfecting clinical contact surfaces.


Cleaning and Disinfection
Strategies for Blood Spills
 Strategies for decontaminating spills of blood and
other body fluids differ by setting and volume of
the spill.
 The person assigned to clean the spill should
wear gloves and other PPE as needed.
 Visible organic material should be removed with
absorbent material (e.g., disposable paper towels
discarded in a leak-proof, appropriately labeled
container).

 Nonporous surfaces should be cleaned and then
decontaminated with either an EPA-registered
hospital disinfectant effective against HBV and
HIV or an EPA-registered hospital disinfectant
with a tuberculocidal claim (i.e., intermediate-
level disinfectant).
 However, if such products are unavailable, a
1:100 dilution of sodium hypochlorite (e.g.,
approximately ¼ cup of 5.25% household
chlorine bleach to 1 gallon of water) is an
inexpensive and effective disinfecting agent.

CLINICAL WASTE DISPOSAL
 Regulated medical waste is only a limited subset
of waste: 9%--15% of total waste in hospitals and
1%--2% of total waste in dental offices.
 Examples of regulated waste found in dental-
practice settings are solid waste soaked or
saturated with blood or saliva (e.g., gauze
saturated with blood after surgery), extracted
teeth, surgically removed hard and soft tissues,
and contaminated sharp items (e.g., needles,
scalpel blades, and wires.

 Regulated medical waste requires careful
containment for treatment or disposal.
 A single leak-resistant biohazard bag is usually
adequate for containment of nonsharp regulated
medical waste, provided the bag is sturdy and the
waste can be discarded without contaminating the
bag's exterior.
 Puncture-resistant containers with a biohazard
label, located at the point of use (i.e., sharps
containers), are used as containment for scalpel
blades, needles, syringes, and unused sterile
sharps.


 All containers with blood or saliva (e.g.,
suctioned fluids) can be carefully poured down a
utility sink or drain.
 Adding 5% hypochlorite in water to sutioned
fluids is recommended before disposing nto the
drain.
 Multiple bloodborne pathogens, particularly
viruses, are not stable in the environment for long
periods, and the discharge of limited quantities of
blood and other body fluids into the sanitary
sewer is considered a safe method for disposing
of these waste materials.


PRINCIPLES AND PROCEDURES FOR
HANDLING AND CLEANING
INSTRUMENTS AFTER TREATMENT
 The safest and most efficient instrument cleaning
procedures involve ultrasonic cleaning of used
instruments kept in a perforated basket or cassette
throughout the cleaning procedure.
 Wear protective utility gloves at all times to
handle contaminated containers and instruments.
 Organic debris on instruments is likely to reduce
activity of the disinfectant.

 Used instruments are commonly placed in an anti
microbial solution as this softens and loosens
debris.
 Next, move the cassettes or basket of instruments
into an ultrasonic cleaning device for cleaning,
rinse them, and then carefully inspect the
instruments for debris.
 Use tongs to remove any instruments left
uncleaned.
 Remove the debris from these instruments
individually, keeping hands well protected with
utility gloves.

 Dip instruments likely to rust into a rust inhibitor
solution. Drain & dry instruments with absorbent
towel.
 Still wearing protective gloves, properly package
the instruments together with internal and
external sterilization indicators suited to the
sterilization process use.
 Cloth packs, wraps, tubes of nylon film, or
commercial paper/plastic bags are suitable for
instrument containment if they are compatible
with, the method and temperature of sterilization.

ULTRASONIC CLEANERS AND
SOLUTIONS
 Ultrasonic cleaning is the safest and most
efficient way to clean sharp instruments.
 An ultrasonic cleaning device should provide fast
and thorough cleaning without damage to
instruments; have a lid, well-designed basket, and
audible timer; and be engineered to prevent
electronic interference with other electronic
equipment


 Operate the tank at one-half to three-fourths full
of cleaning solution at all times- Use only
cleaning solutions recommended by ultrasonic
device manufacturers.
 Operate the ultrasonic cleaner for 5 minutes or
longer as directed by the manufacturer to give
optimal cleaning.
 Devices, that-have less than two transducers do
not pass the foil test and are not suitable for
instrument cleaning.


ULTRASONIC CLEANER FOIL
TEST
 Remove the basket from the device. Add solution,
to the tank, and operate the device for 5 minutes
to expel dissolved gases.
 From a roll of aluminum foil, cut a sheet
approximately 1 inch more than the depth of the
solution in the metal tank . Cut the length 1 inch
less than the length of the tank.
 Hold the foil like a curtain vertically sub-merged
in the solution in the center of the tank
approximately one-half inch above the bottom.

 Operate the device for exactly 20 seconds.
 Upon close inspection, every square one-half inch
of the foil should show small visible indentations
or perforations if the ultrasonic device functions
properly.


STERILIZATION
 There are 4 distinct stages for instrument
sterilization:
1) Pre cleaning disinfection, using holding
solutions
2) Pre – sterilization cleaning.
3) Sterilization
4) Aseptic storage.


 The four accepted methods of sterilization are :
A. Steam pressure sterilization (autoclave)
B. Chemical vapor pressure sterilization-
(chemiclave)
C. Dry heat sterilization (dryclave)
D. Ethylene oxide sterilization
 Patient load, turnaround time for instrument
reuse, size of instrument inventory and
instrument variety, and instrument quality must
all be balanced against the type and size of
sterilizer selected.

STEAM PRESSURE
STERILIZATION (AUTOCLAVING)
 For a light load of instruments, the time required
at 250° F (121° C) is a minimum of 15 minutes at
15 Ibs of pressure.
 Time for wrapped instruments can be reduced to
7 minutes if the temperature is raised to
approximately 273° F (134° C) to give 30 pounds
of pressure.
 Time required for the sterilizer to reach the
correct temperature is not included.

 Steam must enter and circulate around packs
easily. Instrument pans or other impermeable
instrument containers must be left open so steam
can enter.
 Two basic types of steam sterilizers are the
gravity displacement and the high-speed
prevacuum sterilizer.
 Unlike hospital autoclaves, bench models depend
on gravity flow to distribute steam throughout the
load rather than first evacuating air from the
sterilizer and then refilling it with steam.

 Moist heat kills microorganisms through protein
coagulation, RNA and DNA breakdown and
release of low molecular weight intracellular
constituents.
 Advantages of Autoclaves.
 Autoclaving is the most rapid and effective
method for sterilizing cloth surgical packs and
towel packs.
 Is dependable and economical
 Sterilization is verifiable.


 Disadvantages of Autoclaves.
 Items sensitive to the elevated temperature cannot
be autoclaved.
 Autoclaving tends to rust carbon steel instruments
and burs.
 Instruments must be air dried at completion of
cycle.


 Sterilization of Burs in Autoclaves
 Burs can be protected by keeping them
submerged in a small amount of 2% sodium
nitrite solution.
 After ultrasonic cleaning, burs can be rinsed and
placed into any small metal or glass beaker with a
perforated lid.
 Place the container of burs and fluid into the
sterilizer, and operate a normal sterilization cycle.
Discard the fluid from the container through the
perforated lid.


 Use sterile forceps to place the burs into a
sterilized bur holder or tray.
 Before use, any nitrite residue can be wiped
away, or rinsed off with clean or sterile water, if
desired .


CHEMICAL VAPOR PRESSURE
STERILIZATION (chemiclaving)
 The 1938 patent of Dr. George Hollenback and
the work of Hollenback and Harvey in 1940s
culminated in the development of an unsaturated
chemical vapor system , also called Harvey
Chemiclave.
 Principle is that although some water is necessary
to catalyze the destruction of all microorganisms
in a relatively short time, water saturation is not
necessary.
 Kills microorganisms by destroys vital proteins.

 Chemical vapor pres-sure sterilizers operate at
270° F (131° C) and 20 pounds of pressure.
 They must be used with a pre-scribed chemical
and should be properly labeled to satisfy OSHA's
Chemical Hazard Communication Standard.
 Newer models appear to handle aldehyde vapors
also.
 Unsaturated chemical-vapor sterilization involves
heating a chemical solution of primarily alcohol
with 0.23% formaldehyde in a closed pressurized
chamber

 Advantages of Chemiclaves
 Carbon steel and other corrosion-sensitive burs,
instruments, and pliers are said to be sterilized
without rust or corrosion.
 Relatively quick turnaround time for instruments.
 Load comes out dry.
 Sterlization is verifiable.
 Disadvantages of Chemiclaves
 Items sensitive to the elevated temperature will be
damaged. Vapor odor is offensive.
 Heavy cloth wrappings of surgical instruments
may not be penetrated to provide sterilization.

DRY HEAT STERILIZATION
 Conventional Dry Heat Ovens
 Dry heat sterilization is readily achieved at
temperatures above 320° F (160° C) for 30 mins.
 Instrument loads may take 30- 90 mins to reach
that temperature, so to provide a margin of safety,
instruments must be sterilized at 160ºC for 2
hours.
 They have heated chambers that allow air to
circulate by gravity flow (gravity convection).
 Packs of instruments must be placed at least 1 cm
apart to allow heated air to circulate.

 Kills microoragnisms primarily by an oxidation
process. Protein coagulation also occurs
depending on the water content of protein.
 High concentrations of mercury vapor can
develop in a dry heat oven that has been used to
sterilize amalgam instruments. Thus great care
must be taken to scrap amalgam of any
instrument.


 Short-Cycle, High-Temperature Dry Heat
Ovens
 It is a high-temperature process that uses a
forced-draft oven (a mechanical convection oven
that circulates air with a fan or blower)
 It reduces total sterilization time to 6 minutes for
unwrapped and 12 minutes for wrapped
instruments.
 These short-cycle high-temperature dry heat
ovens operate at approximately 370° to 375° F .


 Advantages of Dry Heat Sterilization
 Carbon steel instruments and burs do not rust,
corrode, or lose their temper or cutting edges if
they are well dried before processing.
 Industrial forced-draft hot air ovens usually
provide a larger capacity at a reasonable price.
 Rapid cycles are possible at high temperatures.
 Low initial cost and sterilization is verifiable.
 Disadvantages of Dry Heat Sterilization
 High temperatures may damage more heat-
sensitive items, such as- rubber or plastic goods.


 Sterilization cycles are pro-longed at the lower
temperatures.
 Must be calibrated and monitored.
 Too high temperature may cause instrument
damage.


ETHYLENE OXIDE STERILIZATION (ETO)
 Was first used in 1940’s by US army.
 Ethylene oxide sterilization is the best method for
sterilizing complex instruments and delicate
materials because of extreme penetrability of the
ETO molecule and low temperature(70ºF- 140ºF).
 Kills microroganisms by reacting chemically with
nucleic acids.the basic reaction is alkylation of
hydroxyl groups.
 Sterilization requires several hours and seems
ideal for handpiece sterilization.

 Porous and plastic materials absorb the gas and
require aeration for 24 hours or more before it is
safe for them to contact skin or tissues.
Advantages:
 Operates effectively at low temperatures
 Gas is extremely penetrative
 Can be used for sensitive equipment
 Sterilization is verifiable

Disadvantages:
 Potentially mutagenic and carcinogenic.
 Requires aeration chamber ,cycle time lasts hours
 Usually only hospital based.

 BOILING WATER
 Boiling water does not kill spores and cannot
sterilize instruments.
 Boiling is a. method of high-level disinfection
that has been used when actual sterilization
cannot be achieved (e.g., in case of a sterilizer
breakdown).
 Well-cleaned items must be completely
submerged and allowed to boil at 98° to 100° C
(at sea level) for 10 minutes.


OTHER STERILIZATION
METHODS
 Heat-sensitive critical and semicritical
instruments and devices can be sterilized by
immersing them in liquid chemical germicides
registered by FDA as sterilants.
 Items need to be 1) rinsed with sterile water after
removal to remove toxic or irritating residues;
2) handled using sterile gloves and dried with
sterile towels; and
3) delivered to the point of use in an aseptic
manner.

 They can kill bacterial spores in 6 to 10 hours.
 Sterilants used for high-level disinfection of items
for reuse are glutaraldehydes at 2% to 3%
concentrations.
 High-level disinfection is used mainly for plastic
items that enter the mouth and that cannot
withstand heat sterilization like plastic cheek
retractors and photographic mirrors.
 Disadvantages include prolonged time taken,
irritating to skin & cannot be monitored with
biological indicators.

 NEW METHODS OF STERILIZATION
 Various new methods of sterilization are under
investigation and development.


MONITORS OF
STERILIZATION
 There are 3 methods of monitoring sterilization:
 Mechanical techniques for monitoring
sterilization include assessing cycle time,
temperature, and pressure by observing the
gauges or displays on the sterilizer and noting
these parameters for each load . Correct readings
do not ensure sterilization, but incorrect readings
can be the first indication of a problem with the
sterilization cycle.

 Chemical indicators, internal and external, use
sensitive chemicals to assess physical conditions
(e.g., time and temperature) during the
sterilization process.
 They allow detection of certain equipment
malfunctions, and they can help identify
procedural errors.
 External indicators applied to the outside of a
package (e.g., chemical indicator tape or special
markings) change color rapidly when a specific
parameter is reached, and they verify that the
package has been exposed to the sterilization
process.

 Internal chemical indicators should be used inside
each package to ensure the sterilizing agent has
penetrated the packaging material and actually
reached the instruments inside.
 Biological indicators (BIs) (i.e., spore tests) are
the most accepted method for monitoring the
sterilization process because they assess it
directly by killing known highly resistant
microorganisms (e.g., Geobacillus or Bacillus
species), rather than merely testing the physical
and chemical conditions necessary for
sterilization.

 Spores dried on absorbent paper strips are
calibrated to be killed when sterilization
conditions are reached and maintained for the
necessary time to kill all pathogenic
microorganisms.
 Tests can be evaluated in the office. However, by
sending the strip to a licensed reference
laboratory for testing, the dentist obtains
independent documentation of monitoring
frequency and sterilization effectiveness.


STERILIZATION SPORE TYPE INCUBATION
METHOD TEMPERATURE
AUTOCLAVE Baccilus 56°C
stearothemophilus
CHEMICAL
VAPOR
DRY HEAT Baccilus subtilis 37°C

ETHYLENE
OXIDE


 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.
 In dental offices, sterilization must be monitored
weekly with biologic spore tests using heat-
resistant spores and tested daily with color-
change process-indicator strips.


DENTAL UNIT WATERLINES
 Studies have demonstrated that dental unit
waterlines (i.e., narrow-bore plastic tubing that
carries water to the high-speed handpiece etc.)
can become colonized with microorganisms,
including bacteria, fungi, and protozoa.
 Protected by a polysaccharide slime layer known
as a glycocalyx, these microorganisms colonize
and replicate on the interior surfaces of the
waterline tubing and form a biofilm, which serves
as a reservoir that can amplify the number of free-
floating (i.e., planktonic) microorganisms in
water used for dental treatment.

 It has been demonstrated that microbial counts
can reach <200,000 colony-forming units
(CFU)/mL within 5 days after installation of new
dental unit waterlines , and levels of microbial
contamination <106 CFU/mL of dental unit water
have been documented.
 These counts can occur because dental unit
waterline factors (e.g., system design, flow rates,
and materials) promote both bacterial growth and
development of biofilm.


 In 1995, ADA addressed the dental water concern
by asking manufacturers to provide equipment
with the ability to deliver treatment water with
<200 CFU/mL of unfiltered output from
waterlines.
 This threshold was based on the quality assurance
standard established for dialysate fluid, to ensure
that fluid delivery systems in hemodialysis units
have not been colonized by indigenous
waterborne organisms.


HANDPIECE ASEPSIS
 Oral fluid contamination problems of rotary
equipment and especially the high-speed
handpiece involve:
1. contamination of hand-piece external surfaces
and crevices,
2. turbine chamber contamination that enters the
mouth,
3. water spray retraction and aspiration of oral
fluids into the water lines of older dental units

4. growth of environmental aquatic bacteria in
water lines, and
5. exposure of personnel to spatter and aerosols
generated by intraoral use of rotary equipment.


HANDPIECE SURFACE
CONTAMINATION CONTROL
 Blood and saliva contaminate the surfaces of
handpieces during various dental treatments.
 Irregular surfaces and especially crevices around
the bur chuck are difficult to clean and disinfect,
especially by a brief wipe with a disinfectant-
soaked sponge.
 Submersion of a high-speed handpiece in a high-
level disinfectant has not been an accepted
option.
 Only sterilization can approach complete
infection control of handpiece surfaces.

TURBINE CONTAMINATION
CONTROL
 Contaminated oral fluids may be drawn back-
into the turbine chamber by negative pressure
created either by a Venturi effect during operation
or when the turbine continues to spin whenever
the drive air is stopped.
 Oral fluids also may enter around worn bearing
seals, or be aspirated into the vent holes in the top
of older hand-chuck operated handpieces or
possibly into the air-water spray orifice that
communicates with the turbine chamber.

WATER RETRACTION
SYSTEM CORRECTION
 Dental unit water control systems made before
the 1980s used water lines that easily expanded
when air-water spray was used and gradually
contracted when water pressure was relieved.
Handpieces had a tendency to continue to drip
immediately after having been used.
 To overcome the problem in those units, a device
was installed that retracted water in the line
whenever the spray was stopped but oral fluids
also were retracted.

 The minimal recommendation is to opearte the
handpiece spray for 20 seconds between
appointments to help expel any aspirated
infectious microbes.
 Agencies recommend correcting-water retraction
by placing a one-way check valve in the water
line. Unfortunately check valves clog and fail .
 A simple, inexpensive water retraction testing
device is available that takes only approximately
1 minute to use
 Since 1988, nearly all manufacturers have
manufactured dental control units that simply cut
off the water spray without retraction which is the
best solution.

 Scrub metal-bearing high-speed handpieces and
the sheath or cone of the low-speed straight hand-
piece at the sink with running water and
detergent.
 Autoclave sterilization of handpieces is one of the
most rapid methods.
 Chemical vapor pressure sterilization & ethylene
oxide gas can also be used.
 Dry heat sterilization is not recommended.


INFECTION CONTROL FOR
IMPRESSIONS
 To eliminate any chance of cross-contamination
when sizing impression trays, place the tray in a
plastic bag before it is tried in the mouth.
 Two choices that may be used for preparing a
potentially infectious item for transport:
 send it well cleaned (rinsed) and undisinfected in
a biohazard-labeled, heat-sealed, plastic bag; or
 de-bride, clean (rinse); and adequately disinfect
it, place it in a sealed transport bag labeled with
the precautions taken.

 For rubber-based impression material, Remove
the impression and while still wearing barriers
(remove any attached debris and rinse the item
well with running tap water for 15 seconds to
remove saliva and blood and put in the bag.
 For Aqueous Impression Material Technique
(Using Alginate [Irreversible Hydrocolloid],
Reversible Hydrocolloid, or Polyether
Impressions), thoroughly rinse the impression
under tap water (15 seconds recommended) to
remove any saliva or blood.

 Disinfect the impression by spraying until
thoroughly soaked with a hospital level
disinfectant.
 Thoroughly rinse the disinfected impression
under tap water because any residual disinfectant
can adversely affect surface hardness of the stone
cast.
 Another alternative is to submerge the impression
into a 2% potassium sulfate solution for (up to)
20 minutes, and then remove, shake off excess,
and pour the impression.

Guidelines for Processing and
Sterilization of Endodontic Files
 Clear all instruments of debris by counter-rotating
in alcohol dampened 2x2 gauze pieces.
 Place the files in an available holding solution of
4% glutaraldehyde.
 Files are placed in stainless steel cassettes for
routine ultrasonic cleaning.
 The cassette is then rinsed under running tap
water and and allowed to soak for one
hourin2.5%NaOCl(Household bleach diluted 1:1
with water), at room temperature

 The cassette is then thoroughly rinsed under
running tap water and autoclaved at 134ºC-138ºC
for a minimum of 18 minutes.
 Root canal instruments can also be effectively
sterilized in a dry heat ovens at 320ºF for 2 hours.
 The files are then inspected for damage, sorted by
size and length, and placed in sterile sponges for
use.


 Chairside disinfection of files, absorbent points
and other root canal instruments can be done
before use in a hot salt sterilizer.
 It consists of a metal cup in which table salt is
kept at a temperature between 425ºF(218ºC) and
475ºF(246ºC).
 At this temperature, root canal instruments like
files may be immersed for 5 sec and absorbent
points for 10 sec.


 Pure sodium chloride salt is not used high heat
causes fusion of the granules. Instead table salts
having 1% sodium silicoaluminate, magnesium
carbonate or sodium carbonate is used so that it
pours easily.
 Advantages:
 Uses ordinary table salt which is readily
available.
 Eliminates the risk of clogging the canal unlike
glass beads.
 Small and convenient.
 Serves as an emergency backup.


 Disadvantages:
 Only small sized and number of instruments can
be sterilized
 Sterilization is non verifiable.
 Glass beads can be substituted for the salt if the
beads are less than 1mm in diameter. Larger
beads are not effective because of the large air
spaces.
 The hottest part of the bath is in the outer rim,
starting at the bottom layer of salt, so to use
effectively, the instrument must be immersed at
least quarter – inch below the surface in the
peripheral area.

 Gutta percha cones are sterilized by immersing in
5.2% sodium hypochorite for 1 min, rinsed with
hydrogen peroxide and then dried between 2
layers of sterile gauze.
 Silver cones are sterilized by passing them
through a bunsen flame 3 or 4 times.


 Thank you for watching


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