I ASEPSIS AND INFECTION CONTROL
III OBJECTIVES OF INFECTION CONTROL
IV PRINCIPLES OF INFECTON CONTROL
V PATIENT EVALUATON
VI PATIENT PREPARATION
VII PREPARATION OF THE OPERATORY (INFECTION CONTROL)
VII CLASSIFICATION OF INSTRUMENT STERILIZATION
- CRITICAL ITEMS
-SEMI CRITICAL ITEMS
- NON CRITICAL ITEMS
IX PREOPERATIVE STERILIZATION AND DISINFECTION
X BARRIER TECHNIQUES
XI ROCEDURAL TECHNIQUES (TOOTH ISOLATION)
ASEPSIS AND INFECTION CONTROL
Endodontics has long emphasize the importance of aseptic
techniques using sterilized instruments, disinfecting solutions
such as sodium hypochlorite and rubber dam barriers.
Traditionally Hepatitis B has been the benchmark disease on
which infection control has been based. In an office that
treats 20 patient a day the personnel can expect to
encounter active carrier of Hepatitis B virus (HBV) every 7
working days. In addition one can expect exposure to a
patient with oral herpes and unknown number of patient
infected with Human immuno deficiency virus(HIV).
The transmission route of HIV /HBV is primarily through the
exchange of blood. Percutaneous injury to the dentist is the most
direct patient-to-dentist transmission method. Percutaneous
injuries to dentist are caused by burs (37%), syringe needle(30%),
sharp instruments(21%), orthodontic wires(6%), suture
needles(3%), scalpel blades(1%), and other object(2%).
Dental Professionals are exposed to wide variety of
microorganisms, in the blood and saliva of the patient, making
infection control procedure outmost importance. The common
goal of infection control is to eliminate or reduce number of
microbes shared between the people. The procedures of infection
control must not only protect patient and the dental team from
contracting infections during dental procedures, but also reduce
the number of microorganism in the immediate dental
environment to the lowest level possible.
STERILIZATION- the process that destroys all types and forms of
microorganism,including viruses,bacteria fungi, and bacterial
endospores. Applies to instruments not on skin where antiseptic
can only be achieved. Includes: steam autoclave, dry heat,
chemical vapor under pressure, ethylene oxide gas, and immersion
in liquid chemical disinfectant / sterilizers.
DISINFECTIONS- a process less lethal than sterilization it means
reducing the number of viable microorganism present in a sample.
-High level disinfection- a process that can kill some
but not necessarily all, bacterial spores. It is
tuberculocidal, and if the disinfectant is capable of
destroying bacterial spores it is termed as sporicidal.
- Intermediate level of disinfection - a process that is
capable of killing mycobacterium tuberculosis,
HBV and HIV it may not be capable of killing
- Low level disinfection- kills most bacteria, some
fungi, and some viruses. It does not kill
M.tuberculosis or bacterial spore.
BACTERICIDAL- a process or an agent that destroys bacteria.
BACTERIOSTATIC- a process or an agent that inhibits growth or
multiplication of bacteria.
CONTAMINATION- the introduction of an infectious agent into an
BIOMEDICAL WASTE - waste that has been generally or has been
used in the diagnosis, treatment, or immunization of human being
or animals. May contain infectious agents and may pose substantial
threat to health.
BIOHAZARDOUS WASTE – also called infectious waste or
biomedical waste, is any waste containing infectious
materials or potentially infectious substance. Includes
laboratory waste, specimens sent to a laboratory for
microbiologic analysis, surgical specimen, recognizable fluid
and blood elements and sharps.
MEDICAL SOLID WASTE – empty specimen containers,
bandages or dressings containing nonliquid blood, surgical
globes, treated biohazard waste, and other materials that are
ANTISEPTIC – a chemical agent that is applied to living tissue
to kill microbes.
DISINFECTANT- a chemical or physical agent that is applied to
inanimate object to kill microbes.
III OBJECTIVES OF INFECTION CONTROLIII OBJECTIVES OF INFECTION CONTROL
1. Decrease the number of pathogenic microbes to the
level where normal body resistance mechanisms can
2. Break the cycle of infection from dentist, assistant
and patient and eliminate cross contamination.
3. Treat all patients and instruments as though they
could transmit an infectious disease.
4. Protect patient and personnel from infection and
protect all dental personnel from the threat of
1. Appreciation of basic microbiology and mode of
2. Conscientious hygiene including appropriate hand
washing and cleaning of work area, equipments and
materials in dental office.
3. Use of recommended sterilization and disinfection
4. Use of disposable or sterilizable equipments.
5. Surveillance of potentially capable and occasionally
The identification of patient with transmissible
diseases and of those belonging to high risk group is
essential before treatment begins.
According to the Center for Disease Control and
Prevention (CDC), however because the medical
history and examination cannot reliably identify all
patients with bloodborne pathogens, blood and body
fluid precautions should be consistently used for all
patient. The concept stresses that all patients should
be assumed to be infectious for HIV and other
bloodborne pathogens. The medical history is only an
adjunct to patient’s background and cannot be
considered a totally inclusive source of information.
In the daily practice of Endodontics, one must
frequently re-evaluate the patient’s medical history
at least on a yearly basis. With the recent advances
in the treatment of medically compromised patients,
a greater number of patients will enter the office
with immuno-compromised conditions,
cardiovascular susceptibility, and a host of other
physical limitations that may require special
attention. Consultation with attending physicians is
most important in proper care of such patient.
Regardless of the specifics of the case, the clinician is
responsible for explaining the nature of the treatment and informing
the patient of any risks, the prognosis, and other pertinent facts.
Because of bad publicity and hearsay, root canal treatment is reputed
to be a horrifying experience. Consequently, some patients may be
reluctant, anxious, or even fearful of undergoing root canal
treatment. Thus it is imperative that the clinician educate the patient
before treatment (i.e., “informing before performing”) to allay
concerns and minimize misconceptions.
Good clinician and patient relationships are built on
effective communication. Sufficient evidence suggests that clinicians
who establish warm, caring relationships with their patients through
effective case presentation are perceived more favorably. These
clinicians also have a more positive impact on the patient’s anxiety,
knowledge, and compliance than those who maintain impersonal,
noncommunicative relationships. Most patients experience increased
anxiety while in the dental chair. However, a simple but informative
case presentation that answers all questions reduces patient anxiety
and solidifies the patient’s trust in the clinician.
Because all dental health care personnel (DHCP),
including those not directly involved in patient care,
are at risk for exposure to a host of infectious
organisms (e.g., influenza; upper respiratory disease;
tuberculosis (TB); herpes; hepatitis B, C, D; acquired
immunodeficiency syndrome [AIDS]), effective
infection control procedures must be used to minimize
the risk of cross contamination in the work
1. The ADA and CDC recommend that all DHCP
with a potential occupational exposure to blood
or other potentially infectious material be
vaccinated against hepatitis B.
2. A thorough patient medical history, which
includes specific questions about hepatitis, AIDS,
current illnesses, unintentional weight loss,
lymphadenopathy, and oral soft-tissue lesions,
must be taken and updated at subsequent
appointments. All patents should be screened
for latex allergies, and they should be referred if
an allergy is suspected.
3. Dental personnel must wear protective attire and use proper
barrier techniques. The standard requires the employer to ensure
that employees use personal protective equipment (PPE) and that
such protection is provided at no cost to the employee
a. Disposable latex or vinyl gloves must be
worn when contact with body fluids or mucous membranes is anticipated
or when touching potentially contaminated surfaces; they may not
be washed for reuse. OSHA requires that gloves be replaced after
each patient contact, when torn, or when punctured. If their
integrity is not compromised, sturdy, unlined utility gloves for
cleaning instruments and surfaces may be decontaminated for
reuse. Polyethylene gloves may be worn over treatment gloves to
prevent contamination of objects, such as drawers, light handles,
b. Hands, wrists, and lower forearms must be washed with
either a nonantimicrobial soap or antimicrobial soap and
water when hands are visibly soiled, after bare-handed
touching of inanimate objects likely to be contaminated,
before and after treating each patient, before donning gloves,
and immediately after removing gloves. An antimicrobial
surgical hand scrub should be used for surgical procedures
before donning sterile gloves. The standard requires that any
body area that has contact with a potentially infectious
material, including saliva, must be washed immediately after
contact. It is strongly recommended that hand lotions that do
not affect glove integrity be used to prevent dryness
associated with handwashing. Sinks should have electronic,
elbow-, foot-, or knee-action faucet controls for asepsis and
ease of function.
c. Masks and protective eyewear with solid side shields
or chin-length face shields are required when splashes or
sprays of potentially infectious materials are anticipated and
during all instrument and environmental cleanup activities.
When a face mask is removed, it should be handled by the
elastic or cloth strings, not by the mask itself. It is further
suggested that the patient wear protective eyewear.
d. Protective clothing, either reusable or disposable,
must be worn when clothing or skin is likely to be exposed to
body fluids, and it should be changed when visibly soiled or
penetrated by fluids.
e. Patients’ clothing should be protected from splatter
and caustic materials, such as sodium hypochlorite, with
waist-length plastic coverings overlaid with disposable
f. High-volume evacuation greatly reduces the number
of bacteria in dental aerosols and should be employed
when using the high-speed handpiece, water spray, or
g. Use of the dental dam as a protective barrier is
mandatory for nonsurgical root canal treatment, and
failure to use this barrier is considered to be below
4 Contaminated disposable sharps (e.g., syringes, needles, scalpel blades) and
contaminated reusable sharps (e.g., endodontic files) must be placed into
separate, leak-proof, closable, puncture-resistant containers. These
containers should be colored red or labeled “BIOHAZARD,” and they
should be marked with the biohazard symbol.
a. The clinician should take the following steps when handling
contaminated endodontic files: With tweezers, place used files in glass
beaker containing a nonphenolic disinfectant and detergent holding
solution. At the end of the day, discard solution and rinse with tap water.
Add ultrasonic cleaning solution, and place beaker in ultrasonic bath until
thoroughly clean (i.e., 5 to 15 minutes). Discard ultrasonic solution, and
rinse with tap water. Pour contents of beaker onto clean towel, and use
tweezers to place clean files into metal box for sterilization. Files with any
visible debris should be separately sterilized. Once sterilized, these files
can be picked up by hand and debrided using 2 × 2 inch sponges. Once
cleaned, files should be returned to metal box for sterilization.
b. Generally the standard prohibits bending or recapping of
anesthesia needles. However, during endodontic treatment,
reinjection of the same patient is often necessary, so recapping
is essential. Recapping with a one-handed scoop method and
using a mechanical device are the only permissible techniques;
needles must not be recapped by using both hands or directing
the needle point toward any part of the body. Shearing or
breaking of contaminated needles should never be permitted.
5. Countertops and operatory surfaces, such as light handles,
radiograph unit heads, chair switches, and any other surface
likely to become contaminated with potentially infectious
materials, can be either covered or disinfected. Protective
coverings (e.g., clear plastic wrap, special plastic sleeves,
aluminum oil) can be used. These coverings should be changed
between patients and when they become contaminated.
6 Contaminated radiographic film packets must be handled in a
way that prevents cross contamination. Contamination of the film
(when it is removed from the packet) and subsequent
contamination of the processing equipment can be prevented
either by properly handling the film as it is removed from the
contaminated packet or by preventing the contamination of the
packet during use. After exposure, “overgloves” should be placed
over contaminated gloves to prevent cross contamination of
processing equipment or darkroom surfaces.
7 In conjunction with the previously mentioned guidelines for
infection control, a mouth rinse of 0.12% chlorhexidine gluconate,
such as Peridex (Procter & Gamble, Cincinnati), is suggested before
treatment. This rinse will minimize the number of microbes in the
mouth and, consequently, in any splatter or aerosols generated
during treatment. It should be noted, however, that such mouth
rinses have not proved to reduce the incidence of clinical
8. After treatment, all instruments and burs must be cleaned and
sterilized by sterilizers monitored with biologic indicators. Cassettes,
packs, or trays should be rewrapped in original wrap, and individually
packaged instruments should be placed in a covered container. Air and
water syringes must be flushed, cleaned, and sterilized. handpieces
and “prophy” angles be heat sterilized between patients. Before
sterilization, all handpieces should be wiped with an EPA-registered
disinfectant. In addition, highspeed handpieces should be run for a
minimum of 30 seconds to discharge water and air, with spray
directed into a high-volume evacuation system. Dental unit water lines
should be periodically flushed with water or a 1:10 dilution of 5.25%
sodium hypochlorite (NaOCl) to reduce biofilm formation.
The categorization of instruments depends on the contact
with different tissue types to determine whether sterilization or
disinfection is required.
1. Critical items- instruments that touch sterile areas of the
body or enter the vascular system and those that penetrate
the oral mucosa. eg scalpels, curettes, burs, and files. Must
be sterilized and store in appropriate package, single use
items must be properly discarded.
2. Semi critical items- instruments that touch membrane but do
not penetrate tissues. eg. Amalgam condenser and saliva
ejector. This items should be sterilized; however, if it is not
feasible, high level disinfection is required.
3. Non critical items- those items that do not come in
contact with oral mucosa but are touched by saliva or
blood-contaminated hands while treating patients. eg.
Light switches, counter tops,and drawer pulls on
cabinets. These areas should be properly disinfected.
Sterilization methods that are generally accepted in dentistry:
1. Steam under pressure - Autoclaving
the typical method of sterilization for most health care facilities.
The usual cycle is 30 minutes at 250° F (121° C) at 15 psi. Flash
sterilization at high temperatures of 273° F (134° C) for 10 minutes
and 30 psi is also approved. The Statim brand autoclave uses the
higher temperatures to reduce cycle time.
- better penetration of moist heat
- instruments can be wrapped prior to sterilization,
increases shelf life of instruments.
- does not destroy cotton or cloth produts
- most dental instruments can be autoclaved
- dulling and corrosion of sharp instruments
- item sensitive to elevated temperature and
moisture cannot be effectively autoclaved.
- damage to plastic and rubber products.
- instruments need to be air dried at the end of cycle.
2. Chemical vapor sterilization – Chemclave
Chemiclave uses a solution of 72% ethanol and 0.23%
formaldehyde in place of water in its “autoclave.” This avoids
the instrument corrosion typical of steam autoclaves. They
use 270° F (132° C) at 20 psi for 20 minutes, including drying
time. Arguably a longer cycle time may be needed to meet
guidelines for safety margins. Ventilation or filtration is
required to handle formaldehyde fumes. Chemiclave
chemicals can dissolve into liquids, so liquids should be steam
- fast turn around time and better protection of
carbon steel bur.
- odor that is release when chemicals are heated.
3. Dry heat sterilization
Dry heat sterilizers, either still air in an oven or forced air,
also avoid corrosion of instruments. After preheating the
instruments to sterilizing temperature, still air models
provide sterility in 1 hour at 375° F (191° C). The Cox sterilizer
uses forced hot air of the same temperature and sterilizes in
6 minutes. Wrapped pack increase the time needed for
processing. Hot air sterilizers may require special wraps
- long sterilization time
In-operatory sterilizers were once popular among
clinicians for decontaminating instruments during
treatment. Such sterilizers achieved 450° F (218° C),
and typical cycles were a few seconds for metal
instruments. Glass beads or salt were used to transfer
dry heat to endodontic canal instruments. These
sterilizers are no longer approved for use because of the
possibility that practitioners relied on them for
sterilization between patients. One study found that they
were ineffective at killing spores on cotton and paper
products. Endodontic instruments used for recapitulation
in a canal as it is progressively decontaminated may be
Following patient treatment, barriers should be removed
and surfaces disinfected. Aerosols generated by dental
care can land anywhere, so all surfaces that may be
touched during treatment of the next patient should be
disinfected. Special attention should be given to
instrument holders and hoses. Door and drawer pulls
should be included in the disinfection routine or covered
with barriers. Pens, pencils, and even patient charts
should be considered contaminated. Disinfection of the
treatment room includes wiping all surfaces to be used
with an appropriate disinfectant.
Disinfection- is added to the method for preventing cross
contamination in which sterilization is not possible
disinfects instruments and operatory surface in 1 to 3 mins. when
used correctly. Requires no rinsing and leaves no residue after use.
Disadvantages are corrosion of easily oxidized metals and the need
for fresh solutions for each disinfection process.
suitable for surface disinfection than for instruments sterilization
because of its high corrosive action on metals. Disinfection can
occur in 3 to 30 mins.depending on the amount of debris present.
Dilusion 1:1to 1:5
Iodophors are broad spectrum disinfectant that is effective againts a
host of pathogens, including HBV, M. tuberculosis, poliovirus, and
helpers simple virus. One of the inherent advantages of the
compound is the slow release of elemental iodine to enhance the
bactericidal activity. Dilution 1:213 of soft or distilled water hard
water inactivates the iodophor. Biocidal activity occurs within 30
Not accepted by ADA for disinfection of surface or instruments.
Quarternary Ammonium Compounds
This group of compounds including benzalkonium chloride, is no
longer recommended for instrument or surface disinfection. All
quarternary ammonium compounds have been disapproved by the
ADA for use in dentistry.
Barrier techniques in infection control address the quantity
factor in disease prevention. This may encompass protection
of the body surfaces, protection of the environmental
surfaces, or blockage of bacteria from the source.
provide the patient with protection from contamination of
microorganisms on the practitioners hands and protect dental
health care workers from contaminations by the patients
blood and saliva.
hands should be washed before gloves are placed and after
gloves are removed bec. the integrity of the glove is not
The face masks is an important barrier providing protection
from inhalation of aerosols generated by high speed
handpiece and air water syringes. Should remain dry to
prevent transmission of organisms through moisture
Protective eye ware is highly beneficial for dental care
providers and for the patient. Helpers virus infection of the
eye and infection from hepatitis B are possible consequences
of viral contact with the eye.
The general recommendations for clinic wear include
reusable or disposable gowns and laboratory coats or
uniforms with long sleeves. Head covers are also
recommended during procedures that result in splashing
blood or other body fluids.
The use of the rubber dam is mandatory in root canal
treatment. Developed in the nineteenth century by S.C.
Barnum, the rubber dam has evolved from a system that
was designed to isolate teeth for placement of gold foil to
one of sophistication for the ultimate protection of both
patient and clinician. The advantages and absolute
necessity of the rubber dam must always take
precedence over convenience and expediency. When
properly placed, the rubber dam facilitates treatment by
isolating the tooth from obstacles (e.g., saliva, tongue)
that can disrupt any procedure. Proper rubber dam
placement can be done quickly and will enhance the
The rubber dam is used in endodontics because it ensures the following
1. Patient is protected from aspiration or from the swallowing of instruments,
tooth debris, medicaments, and irrigating solutions.
2. Clinician is protected from litigation because of patient aspiration or
swallowing of an endodontic file. Routine placement of the rubber dam is
considered the standard of care.
3. A surgically clean operating field is isolated from saliva, hemorrhage, and
other tissue fluids. The dam reduces the risk of cross contamination of the
root canal system, and it provides an excellent barrier to the potential
spread of infectious agents. It is a required component of any infection
4. Soft tissues are retracted and protected.
5. Visibility is improved. The rubber dam provides a dry field and reduces
6. Efficiency is increased. The rubber dam minimizes patient conversation
during treatment and the need for frequent rinsing.
Components of rubber dam:
The mainstay of the rubber dam system is the dam
itself. These autoclavable sheets of thin, flat latex come
in various thicknesses (e.g., thin, medium, heavy,
extraheavy, special heavy) and in two different sizes (5
× 5 inches and 6 × 6 inches).
Another component of the rubber dam system is the
rubber dam frame, which is designed to retract and
stabilize the dam. Both metal and plastic frames are
available, but plastic frames are recommended for
endodontic procedures. They appear radiolucent, do
not mask key areas on working films, and do not have
to be removed before film placement.
Methods of Rubber Dam Placement
The method of dam placement is to position the bow of
the clamp through the hole in the dam and place the
rubber over the wings of the clamp (a winged clamp is
required).The forceps stretch the clamp to maintain the
position of the clamp in the dam, and the dam is
attached to the plastic frame, allowing for the placement
of the dam, clamp, and frame in one motion. Once the
clamp is secured on the tooth, the dam is teased under
the wings of the clamp with a plastic instrument.
A, Rubber dam, clamp, and frame. B, Dam, clamp, and frame carried to mouth as
one unit and placed over the tooth. C,
Clamp in place with four-point contact and rubber tucked under the wings.
Another method is to place the clamp, usually wingless,
on the tooth and then stretch the dam over the clamped
tooth .This method offers the advantage of enabling the
clinician to see exactly where the jaws of the clamp
engage the tooth, thus avoiding possible impingement
on the gingival tissues. Gentle finger pressure on the
buccal and lingual apron of the clamp before the dam is
placed can be used to test how securely the clamp fits.
Variations of this method include placing the clamp and
dam first, followed by the frame, or placing the rubber
dam first, followed by the clamp and then the frame.
A, After the clamp is placed, the dam is attached to the frame and gently stretched over
the clamped tooth with the index
finger of each hand. B, Clamp is tested for a secure fit with gentle finger pressure
(alternately) on the buccal and lingual aspects of the
Insti-Dam is a disposable dam system available in both latex and nonlatex. A, Bendable
flexible frame allows for easy
placement. B, Use of Insti-Dam during endodontic treatment. (Courtesy Zirc Company,
A third method, the split-dam technique, may be used to
isolate anterior teeth without using a rubber dam clamp. Not
only is this technique useful when there is insufficient crown
structure, as in the case of horizontal fractures, but also it
prevents the possibility of the jaws of the clamp chipping the
margins of teeth restored with porcelain crowns or laminates.
Studies on the effects of retainers on porcelain-fused-to-metal
restorations and tooth structure itself have demonstrated that
there can be significant damage to cervical porcelain, as well
as to dentin and cementum, even when the clamp is properly
stabilized. Thus for teeth with porcelain restorations, ligation
with dental floss is recommended as an alternate method to
retract the dam and tissues, or the adjacent tooth can be
Split-dam technique. A, Premolar clamp on maxillary central incisor along with ligation on
the maxillary canine prevents
dam slippage and aids in dam retraction during endodontic treatment on broken-down
maxillary lateral incisor. B, Split dam used during
post removal and retreatment of a maxillary central incisor. (A Courtesy Dr. James L.
Gutmann. B Courtesy Dr. Francisco A. Banchs.)
Rubber dam clamps are color coded for ease in identification.
(Courtesy Coltene/Whaledent, Inc., Cuyahoga Falls,
Hepatitis B is a major health hazard for dental health
personnel. Because of this risk, the ADA Council on
Therapeutics and the CDC have recommended that all dental
personnel involved in patient care can receive the hepatitis B
vaccine if they do not already immunity as a result of previous
exposure to virus.
1. plasma-derived HB vaccine
2. recombinant DNA HB vaccine
Vaccine plays an important role in infection control process
but many blood borne pathogens exist for which there is
presently no vaccine including HIV. Proper infection control
procedure are therefore important to prevent transmission of
PATHWAYS OF THE PULP 9th
Text book of endodontics
by: Nisha Garg and Amit Garg
by: Ingle and Bacland