Infection Control Guidelines for Dental Clinics Infection Prevention in Dental Clinics

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KING KHALID HOSPITAL
INFECTION PREVENTION
AND
CONTROL MANUAL
DENTAL CLINIC AND
DENTAL LABORATORY
Dr. Nahla Abdel Kader, MD, PhD.
Infection Control Consultant, MOH
Infection Control CBAHI Surveyor
Infection Prevention Control Director
KKH.

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DEFINITION
To provide guidelines on proper infection control
practices in the Dental care setting.
COMMENTS
1. Patients and Dental Health Care Workers (DHCWs) may be exposed to a variety of
infectious, viral, and bacterial agents in dental care settings.
a. Routes of microbial transmission
i. Direct contact with a lesion, organisms, or potentially infectious secretions when
performing intra oral procedures. E.g. practicing without wearing gloves.
ii. Indirect contact via contaminated instruments or disposable items. e.g. accidental
percutaneous exposures from used needles.
iii. Aerosolization of microorganisms from patient’s blood or saliva while using
devices. e.g. air water devices, dental hand pieces

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b. DHCWs and patients as modes of transmission
during patients care:
i. Patient to DHCW: passage of potentially infectious
microbes, can occur through breaks in the skin or
through airborne exposure.
ii. DHCW to patient exposure: this transmission
represents a microbial challenge, as a result of
accidental bleeding into a patient’s mouth after an
accidental sharps exposure or through respiratory
droplets passed from DHCW to the patient.
iii. Patient to patient transmission: Can occur if
instruments improperly reprocessed or improper
hand hygiene

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PROCEDURE
Treat every patient and instrument as potentially infectious with
a life treating
bloodborne pathogen.
1. Hepatitis B Vaccination:
All susceptible DHCWs should obtain vaccination against
hepatitis B. This vaccine is provided free of charge to at-risk
employees by National Guard Health Affairs.
2. Standard Precautions:
a. Practice standard precautions (hand hygiene, mask, gloves,
goggles, face shield, gowns, or aprons). Refer to ICM – II-03
b. Dispose sharps properly in puncture proof containers; do not
bend or recap refer to ICM – IX-02.
c. Use impervious-backed paper, aluminum foil, or plastic
covers to protect items and surfaces (e.g., light handles of x-ray
unit heads) that may become contaminated by blood or saliva
during use and that are impossible to clean and disinfect.
Between patients, remove these covers (while still gloved),
discard them, and replace (after ungloving and washing hands)
with clean materials.

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3. Preprocedural mouth rinsing:
Use it as routine for all patients to reduce the number of
micro-organisms in the mouth before any procedure.
4. Unit dose concept:
Dispense the sufficient amount of material to accomplish a
particular procedure before patient contact.
5. Patient interview:
Always obtain and determine the current health status of
the patient; and always perform a through head, neck and
oral examination (examination may indicate a need for
medical referral for the patient (i.e. for diagnosis of active
infection).
6. Management of needlestick injuries/ blood and body fluid
exposure: Refer to ICM – VII-04 Management of Needlestick
and Body Fluid Exposure
7. Work restriction for DHCWs:
Refer to ICM – VI-04 Work Restriction for Infected Health
Care Workers.

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8. Cleaning, Disinfection, and Sterilization:
a. General principles
All dental and medical instruments can be classified into 3
categories reflecting their infection risk and how to process
them:
i. Critical instruments penetrate soft tissue or bone and should be
sterilized after each use. Examples include forceps, scalpels,
bone chisels, scalers, and burs.
ii. Semicritical instruments do not penetrate soft tissues or bone
but contact oral tissues and mucous membranes, and they
should be sterilized; if sterilization is not feasible because heat
will damage the instrument, then the item should receive a
high-level disinfection. Examples include mirrors and amalgam
condensers.
iii. Non critical instruments come into contact only with intact
skin and may be processed with intermediate-level or low-level
disinfection, or with detergent and water, depending on the
nature of the surface and the degree and nature of the
contamination. Examples include x-ray heads

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b. Dental instruments
i. Wear heavy-duty (reusable utility) gloves when cleaning and
reprocessing to lessen the risk of injuries.
ii. Cleaning:
▪▪ Clean the instruments thoroughly to remove debris prior to
sterilization or disinfection.
▪▪ Place the instruments into a container of water or disinfectant/
detergent as soon as possible after use to prevent drying of
organic material and make cleaning easier.
▪▪ Scrub instruments thoroughly with soap and water or a
detergent solution, or with a mechanical device such as an
ultrasonic cleaner. Covered ultrasonic cleaners are
recommended to increase efficiency of cleaning and to reduce
handling of sharp instruments.
iii. Sterilization:
▪▪ Sterilize all heat-stable critical and semicritical dental
instruments between uses by steam under pressure
(autoclaving), dry heat, or chemical vapor, following
manufacturer’s instructions for instruments and sterilizers

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▪▪ Package critical and semicritical instruments that will not be used immediately
before sterilizing them.
▪▪ Use a biological indicator (i.e., spore tests) at least weekly to verify proper
functioning of sterilization cycles (see Appendix 1).
▪▪ Place a heat-sensitive chemical indicator (i.e., those that change color after
exposure to heat) inside and in the center of either a load of unwrapped
instruments or in each multiple instrument pack to confirm heat penetration to
all instruments during each cycle.
▪▪ Follow manufacturers’ instructions for dental instruments and sterilization
devices.
i. High-level disinfection:
▪▪ Use an U.S. Environmental Protection Agency (EPA)-registered
“sterilant/disinfectant” liquid chemical to achieve high-level disinfection of
heat-sensitive semicritical dental instruments.
▪▪ Follow product manufacturer’s instructions regarding appropriate
concentration and exposure time for the “sterilant/ disinfectant.”
▪▪ Check the chemical label for the “sterilant/disinfectant” designation. Liquid
chemical agents that are rated less potent than the “sterilant/ disinfectant”
category are not appropriate for reprocessing critical or semicritical dental
instruments

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c. Dental unit and environmental surfaces
i. After treatment of each patient and at the completion of daily work
activities, clean countertops and dental unit surfaces that may have
become contaminated with patient material. Use paper towels, an
appropriate cleaning agent, and water for cleaning.
ii. Cleaning environmental surface contaminated with patient
material, with a chemical germicide registered with the U.S. EPA as
a “hospital disinfectant” and labeled “tuberculocidal.” Examples of
such intermediate-level disinfectants include phenolics, iodophors,
and chlorine-containing compounds such as diluted household
bleach (sodium hypochlorite).
iii. Prepare a fresh solution of 1:100 dilution sodium hypochlorite as
an inexpensive intermediate-level disinfectant, add ¼ cup of
household bleach to 1 gallon of tap water. This solution is active for
only 24 hours and must be prepared fresh each day. Caution should
be exercised because chlorine solutions can corrode metals such as
aluminum.
iv. Clean floors, walls, and other surfaces with EPA-registered
“hospital disinfectants” that are not labeled for “tuberculocidal”
activity. An example of such a low-level disinfectant is a quaternary
ammonium compound

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9. Use and Care of Handpieces, Anti-retraction valves, and other
Intraoral Dental Devices attached to Air and Water Lines of Dental
Units:
a. Heat-sterilize all high-speed dental handpieces, low-speed
handpiece components used intraorally and reusable prophylaxis
angles. Acceptable methods of sterilization include steam under
pressure (autoclaving), dry heat, or heat/chemical vapor. It is NOT
acceptable to reprocess high-speed dental handpieces, low-speed
handpiece components used intraorally, and reusable prophylaxis
angles by wiping or soaking these instruments in liquid chemical
germicides.
b. Follow manufacturer’s instructions for cleaning, lubrication, and
sterilization of handpieces and reusable prophylaxis angles to
ensure effective sterilization and longevity of the instruments.
c. Install anti-retraction valves (one-way flow check valves) in dental
unit water lines to prevent fluid aspiration and to reduce the risk of
transfer of potentially infective material. Ensure routine
maintenance of antiretraction valves.
d. Run high-speed handpieces to discharge water and air for a
minimum of 20-30 seconds after use on each patient. If possible,
use an enclosed container or high-velocity evacuation during
discharge procedures to minimize spread of spray, spatter, and
aerosols

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e. At the beginning of each clinic day, remove handpieces and allow
water lines to run and discharge water for several minutes to
reduce and overnight microbial accumulation.
f. Use sterile water or saline as a coolant/irrigator when surgical
procedures involve cutting bone or tissues.
g. After treatment of each patient, clean and sterilize reusable
intraoral instruments attached to, but removable from, the dental
unit air or water lines (e.g., ultrasonic scaler tips and component
parts and air/water syringe tips) in the same manner as
handpieces. Follow manufacturers’ instructions for reprocessing.
h. Some dental instruments have components that are heat-sensitive
or are permanently attached to dental unit water lines. Other
instruments (e.g., handles or dental unit attachments of saliva
ejectors, high-speed airevacuators, and air/water syringes) which
do not enter the patient’s mouth can become contaminated with
oral fluids during treatment procedures. Cover these instruments
with impervious barriers that are changed after each use, or, if
possible, clean and then disinfect with an EPA-registered “hospital
disinfectant” that is labeled “tuberculocidal”.
i. Flush all water lines to all instruments thoroughly after the
treatment of each patient, and at the beginning of each clinic day

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10. Water Quality:
a. The Dental Unit Water System (DUWS) are contaminated
by organisms that colonize the system and water lines and
soon after form biofilms inside the lumens of the water lines.
Although the water coming into the system from an external
source is of potable quality (<500 cfu/mL of bacteria and <1
coliforms), water coming out of the units may be
contaminated to 1 million cfu/mL.
b. This contamination occurs because dental unit water line
factors (e.g., system design, flow rates, materials) promote
bacterial growth and development of Biofilm.
i. Successful engineering and manufacturing of these and
other options for improving the ability to deliver treatment
water with 200 cfu/mL or less of unfiltered output from
water lines and continue to provide DHCWs with multiple
choices for exerting better control over the quality of source
water used in patient care. These choices are as follows:

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ii. An alternate water supply that bypasses community water
systems and DUWS by providing sterile or distilled water
directly into water line attachments (i.e., separate
reservoir) combined with chemical treatment.
iii. Filtration involving in-line filters to remove bacteria
immediately before dental unit water enters instrument
attachment.
iv. Chemical disinfection involving periodic flushing of lines
with a disinfectant followed by appropriate rinsing of lines
with water or a continuous-release chemical disinfection
system.
v. Thermal inactivation of facility water at a centralized
source.
vi. Reverse osmosis or ozonation using units designed for
either single-chair or entire practice water lines.
vii. Ultraviolet irradiation of water before entrance into
individual unit water lines

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11. Single-Use Disposable Instruments:
Use single-use disposable instruments (e.g., prophylaxis angles;
prophylaxis cups and brushes; tips for high-speed air evacuators,
saliva ejectors, and air/ water syringes) for one patient only and
discard after use.
12. Handling of Biopsy Specimens:
a. Place each biopsy specimen in a sturdy container with a secure
lid to prevent leaking during transport.
b. Avoid contaminating the outside of the specimen container. If
the outside is visibly contaminated, clean and disinfect it, or
place it in an impervious bag.
13. Disposal of Infectious Waste Materials:
a. Pour blood, suctioned fluids, or other liquid waste into a drain
connected to a sanitary sewer system.
b. Place solid waste contaminated with blood or other body fluids
in sealed, sturdy impervious bags that are leak-proof refer to
ICM – IX-02 Infectious Waste Management.

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14. Practices for the Dental Laboratory:
a. Separate the receiving area from the production area. Clean
and disinfect countertops and work surfaces daily.
b. Clean and disinfect laboratory materials and other items
that have been used in the mouth (e.g., impressions, bite
registrations, fixed and removable prostheses, orthodontic
appliances) before manipulating them in the laboratory.
After manipulation, clean and disinfect these items again
before placing them in the patient’s mouth (see Table 1).
c. Use a chemical germicide registered with the EPA as
“hospital disinfectant” and “tuberculocidal” (i.e., an
intermediate-level disinfectant) to disinfect laboratory
materials.
d. Disinfect all incoming cases as they are received. Sterilize or
disinfect containers after each use. Discard packing
materials to avoid cross contamination

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e. Production area:
i. Wear a clean uniform or laboratory coat, a face mask,
protective eyewear, and disposable gloves.
ii. Clean debris from work surfaces and equipment, and disinfect
daily.
iii. Separate instruments, attachments, and materials to be used
with new prostheses/appliances from those to be used with
prostheses/ appliances that have already been inserted in the
mouth.
iv. Wash and autoclave ragwheels after each case.
v. Disinfect brushes and other equipment at least daily.
vi. Dispense a small amount of pumice in small disposable
containers for individual use on each case and discard the
excess. A 1:20 dilution of sodium hypochlorite can be used as a
mixing medium for pumice. Add 3 parts green soap to the
disinfectant solution to keep the pumice suspended.
f. Disinfect each outgoing case before it is returned to the dental
clinic.

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15. Dental Radiology Asepsis:
a. Multiple opportunities for cross-contamination of equipment and
environmental surfaces exist when taking and developing dental
radiographs.
i. Gloves should be worn when taking radiographs and handling
contaminated film packets. Other PPE (e.g., mask, protective
eyewear, protective clothing) is required when spatter or splashing
of blood or other potentially infectious materials is anticipated.
ii. Even where there is no generation of splash or spatter, it is suggested
to wear a mask when taking radiographs. Because of the close
proximity to the oral cavity during the procedure, respiratory
infections can be transmitted to DHCWs.
iii. After exposure of dental radiographs, care must be taken when
handling the contaminated films.
b. If protective covers are used over films during exposure, the
following steps are performed:
i. While wearing gloves, remove and discard the covers without
contaminating the film.
ii. Remove gloves and perform hand hygiene.
iii. Process the films

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c. If protective covers are not used over films during exposure, the
following steps are performed:
i. While wearing gloves, place the contaminated films into a
container.
ii. Remove gloves and perform hand hygiene.
iii. Don a fresh pair of gloves and transport the container to the
darkroom.
iv. Carefully open the film packet and drop the films on a clean
surface.
v. Discard the contaminated film packet wrappers.
vi. Remove gloves and perform hand hygiene.
vii. Process the films. Surface cleaning and disinfection procedures
for radiography equipment are the same as in the dental operatory.
d. Using impermeable disposable surface barriers is encouraged,
especially on surfaces that are difficult to clean and disinfect (e.g.,
x-ray control panels), and can be considered a timesaving
procedure.
e. Lead aprons and thyroid shields should be cleaned and disinfected
if they become contaminated

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