The guideline The
Prevention of Infection
in Dental Practice
is a revision
of the guideline on practical
hygiene in dental practice that was published in 1995, which has now been
superseded. The recommendations set out in this guideline are intended for dentists
and practice employees. The recommendations are based on a careful analysis of
the literature, the expertise of the members of the subcommittee which drew up
the guideline and the members of the Dutch Working Party on Infection
Prevention, and national observations.
Personal hygiene
Good personal hygiene contributes to the prevention of
infection in dental practice and also protects employees themselves against
infections.
Nails
Nails should be cut short and be clean .
Nail varnish should be intact, i.e. no chips or flakes.
Artificial nails are not permitted. Artificial nails can be
a source of contamination.
Hair
Hair should be clean.
Long hair should be worn tied up or tied back.
Beards and moustaches
Beards and moustaches should be well cared for and cut
short.
Jewellery
No rings, bracelets or wristwatches should be worn during
work.
It is not possible to wash hands and/or lower arms if these
are covered in jewellery.
Piercings are regarded as jewellery. If a piercing hampers
the treatment/care of a patient, it should be removed.
Use of handkerchiefs
Paper handkerchiefs should be used during work.
After use handkerchiefs should be immediately thrown away
and hands should be washed or disinfected.
The sign in the margin ("a little hand") means
that this is a recommendation,
i.e. a preferred measure recommended by the Working Group. handkerchiefs
that are carried in trouser pockets or elsewhere in clothing can act as a
source of contamination and contaminate the hands every time that they are
touched.
Eating, drinking and smoking
In critical and semi-critical areas no eating, drinking or
smoking is permitted.
See below for the terms critical and semi-critical areas.
Clothing
During the treatment
of patients and
the handling of
used instruments clothing with short sleeves should be worn in
order to make good hand hygiene possible.
This clothing should
be changed daily
and in the
case of visible
contamination immediately.
During treatment clothing should not be touched with the
hands (gloves).
Infections
A dentist or
an employee with
an infection, for
example a bronchial
infection or diarrhoea or
is a carrier
of pathogenic micro-organisms, may
be a source
of contamination for patients
and colleagues. Sometimes they should
refrain from treating patients
and should avoid
contact with patients
who are extra-sensitive to infections, such as patients who are being
given immunosuppressants. If there is any doubt, it is a good idea to ask the
advice of a doctor.
Immunisation
All dentists and all the practice employees should be
vaccinated against hepatitis B because of the risk of exposure to blood and the
possible risks this causes.
Immunity to hepatitis B should be checked a month after the
last injection. People who have not been vaccinated are subject to the
guideline 'Preventive iatrogenic hepatitis B.
A policy should
be pursued relating
to the vaccination
status of employees
for hepatitis B, polio,
rubella and whooping
cough and the
registration of these
in accordance with the
national vaccination programme
and the policy
of the Commission for the
Prevention of Iatrogenic Hepatitis B.
Hand hygiene
Introduction
The skin is composed of various layers, with microorganisms
in the upper layers. The micro-organisms present can be roughly separated into:
- Resident micro-organisms, or permanent
flora and
- Transient micro-organisms or temporary
flora.
The resident flora
include the micro-organisms that
are present in
the deeper skin layers. These micro-organisms are
virtually impossible to remove from the deeper skin layers. In general,
resident micro-organisms are hardly pathogenic (a cause of illness). flora include
the micro-organisms that
are on top
of the skin and that have
got there through
contact with other
people or with
objects, etc. These
micro- organisms are called
transient because they
can be easily
removed by washing
the hands with soap and water.
The hands are
a major source
of contamination. The
effectiveness of good
hand hygiene has been
demonstrated for the prevention of
infection . There is a difference
between hand-washing using soap and water and rubbing hand alcohol into the
hands. Hand washing and rubbing the hands with hand alcohol are regarded as
the most important
measure for reducing
the risk of
the transfer of
microorganisms from one person to another or from one body part to
another.
Hand alcohol is the collective name for the alcohol
preparations that are used for non- preoperative hand-disinfection and
it can be
based on either
ethanol or isopropanol.
The addition of
chlorohexidine or another
disinfectant does not
contribute to the immediate germicidal effect that alcohols
already have; however, this does have a longer-lasting effect.
In view of the usual
duration of dental interventions (less than two hours) this effect is not
necessary.
N.B. The use of disinfectant soap or chlorohexidine scrub is
not useful for the same reason.
N.B. The frequent
use of soap
(over 10 x
a day) when
replacing gloves between patients has
dermatological
disadvantages. For this
reason too hand
alcohol is recommended.
Hand washing or disinfecting?
For hand hygiene
a choice can
be made between
washing the hands
with soap and water
and rubbing hand alcohol
into them. The advantage of using hand alcohol compared
with washing the hands with soap and water is that it costs less and is less harmful
to the hands.
If the hands are visibly contaminated, they should always be
washed with water and normal liquid soap.
Hand alcohol does not clean the hands.
Hand washing or disinfection methods
Water tap
The water tap should not be touched with the
hands and should therefore have an
elbow control, foot control or infrared sensor.
Dispensers
Soap and hand alcohol dispensers should be designed in such
a manner that they can be operated using the elbow and, when used, the hands
cannot contaminate the soap in the nozzle.
Dispensers should have a disposable reservoir that cannot be
refilled. The entire bottle should be replaced when the dispenser is empty.
The dispenser should be cleaned when the reservoir is
replaced.
Wounds
Open wounds on
the hands or
skin lesions should be covered
with a waterproof plaster, even if gloves are worn.
Drying
Disposable paper towels should be used for drying the hands.
Creams
If the hands are washed, it is important that a fairly rich
hand cream is used from a tube or dispenser so that the hands remain
unblemished despite the frequent washing.
Creams should be
used from small
tubes or from
dispensers with disposable containers that are not refilled.
The use of a cream helps to prevent the drying-out of the
skin.
Technique for hand washing
1. Wet the hands
with water from a fast-running tap and cover them with a layer of liquid soap
from a dispenser without touching the tap or the dispenser.
2. Rub the hands
together vigorously for 10 seconds; the soap should be rubbed well into
the fingertips, the
thumbs, the areas
between the fingers
and the wrists.
3. Rinse the hands
well.
4. Turn off the tap
as indicated in section.
5. Dry the
hands with a
disposable towel, including
the wrists and
the skin between the fingers.
6. Throw the used
towel into the waste bin intended for this purpose.
Technique for rubbing hand alcohol into hands
1. Apply the hand alcohol from the dispenser to
the dry hands without touching the dispenser's nozzle.
2. Take sufficient
hand alcohol to fill the hollow of one hand.
3. Carefully rub
the hands together
for around 30
seconds until they
are dry. The hand alcohol should
also be rubbed well into the fingertips, the thumbs, the areas between the
fingers and the wrists.
N.B. Certain parts of the hands are often forgotten.
Frequently forgotten parts of the hands are the fingertips, between the fingers
and the thumbs.
Indications for hand washing / disinfection
Hands should always be washed or be rubbed with hand
alcohol:
- before and after each patient;
- after blowing one's nose;
- after coughing and sneezing;
- after a visit to the toilet;
- before handling equipment that is ready for
use;
- after handling used equipment.
Personal protective equipment
Gloves
Wearing gloves:
- prevents
hands coming into
contact with blood,
saliva and mucous membranes. This
is important because
of the risk
of contamination of the
dentist or the employee.
- reduces
the risk of
micro-organisms being transferred
from one patient
to another via the dentist's or employee's hands.
Non-sterile gloves
Gloves should always be worn when the hands come or could
come into contact with blood, saliva,
mucous membranes or
with treatment materials
and contaminated equipment that has been in contact with these.
Gloves should be
removed immediately after
these treatments. They
should not ome into
contact with clothing
and equipment in
the surrounding area
such as telephones, door handles,
instruments, keyboards, etc.
New gloves should be worn for each patient.
Working without gloves is only allowed when using a "no
touch" technique.
Immediately after the gloves are removed they should be put
into the waste and the hands should be washed using soap and water or be rubbed
with hand alcohol.
Wearing gloves is not an alternative to hand-washing or
disinfection. Refer to the
WIP guideline: Personal protective equipment.
Approved gloves meet the prescribed standards that are shown
on the packaging. In The Netherlands this is the standard for gloves that
provide protection against chemicals and micro-organisms (EN 455-1/2/3). Latex
gloves may contain substances that cause strong allergic reactions in people who
are sensitive to them. In this case latex-free gloves should be used. This applies
to all employees at the practice.
Washing or disinfecting gloves (using hand alcohol) between
patient treatments is not permitted.
Gloves can "break
down", which means
that they let
moisture through small, unnoticed holes. Moreover,the quality
of the gloves can significantly deteriorate because of the effect of disinfectants,
oils and lotions.
If the gloves are damaged during treatment by needles or
other sharp objects, new gloves should be put on.
Sterile gloves
If sterile surgical interventions are carried out, the
gloves worn should be sterile.
A sterile intervention
is when there
is contact with
sterile tissue and
bone is exposed. Examples are the
removal of impacted elements and the preparation and placing of implants and
apex resections, Surgical Interventions).
Before sterile gloves are put on, hand alcohol should be
rubbed into the hands. If gloves are
damaged during treatment
by needles or
other sharp objects,
new gloves should be put on.
Rubber gloves
Sturdy gloves should be worn when cleaning equipment.
Eye protection
The purpose of
eye protection is
to protect the
wearer against airway
secretions or splashes and
squirts of blood or other bodily fluids, secretions or excretions.
There are three ways to protect the eyes:
Protective glasses
Normal glasses cannot
serve as protective
glasses because in
the case of splashes
or squirts the
head turns away
on a reflex
and the sides
of normal glasses do not offer
any protection.
Face shield
Mask with splash shield.
protection should be worn for treating every patient where
there is a risk of splashes or aerosols
of blood, saliva
or rinse water
and when handling
soiled equipment.
The reusable eye
protection should be
cleaned and then
disinfected with 70% alcohol after every treatment that
involves contamination.
Mask
A surgical mask should be worn for treating every patient
where there is a risk of splashes
or aerosols of
blood, saliva or
rinse water and
when handling contaminated
equipment.
A new mask should be used for every patient. This also
applies if the mouth/nose mask gets wet.
A normal surgical mask can provide the protection. This mask
provides protection against splashes but does not provide protection against
the breathing in of small droplets. The
circumstances under which
the use of
eye protection and
a mask should
be used are the same; they should therefore always be worn together.
Accidental contact with blood
Accidental contact with blood means exposure to blood or to
bodily fluids that have been
visibly contaminated with
blood by a
percutaneous wound or
through contact with mucous
membrane or broken skin.
Accidental contact with blood as a result of puncture/cut
accidents occurs mainly in
the following situations:
- while cleaning sharp equipment (over half
of cases),
- while carrying out interventions (around
40% of cases),
- while administering a local anaesthetic,
- while returning a needle to a sleeve.
In addition, a prick accident can occur when placing an
unprotected used needle in a
needle container. People can also prick themselves on unprotected
needles.
Accidental
contact with blood
will occur more
often in situations
of high work
pressure and in particular in critical situations.
Prevention of accidental contact with blood
First and foremost work should be carried out as tidily and
as orderly as possible.
Equipment should be cleaned by machine instead of by hand.
Gloves should be worn during the administration of
anaesthetic.
Needles should not be bent, broken or otherwise manipulated.
Needles should not be guided using the fingers.
The disposable needle used for (re)anaesthetising a patient
should be placed back into the sleeve using one hand only.
The needles should be placed in a needle container after
use.
The needle containers should meet the set requirement.
The containers are made of hard plastic and have a device
that makes it possible to
separate the needle
from the syringe
or the needle
holder without touching
the
needles with the hands. The needle containers should close
in such a way that they
cannot open spontaneously
and cannot be reopened.
It should not
be possible to
puncture the containers with needles and the containers
should be leak-proof [16].
Needle containers should be regularly replaced.
The needle containers should not be overfilled. Therefore
they should not be filled
above the line indicated on every needle container.
For the handling
of used equipment
gloves should be
worn that protect
against pricks and cuts.
Procedure following accidental contact with blood
Following accidental contact with blood let the wound
continue to bleed and rinse
the wound (using water or physiological salt). Then
disinfect the wound using a
skin disinfectant.
In the case of contamination of the mucous membranes rinse
immediately and as
well as possible with water or physiological salt. This
water or physiological salt
should not be swallowed.
Every dental practice
should make arrangements
about the further
treatment of accidental contact with blood. This can be
done in various ways, for example via the
Occupational Health &
Safety Inspectorate or
the GGD (Municipal
Health Service).
Extended policy on accidental contact with blood is set out
in the national guideline: Accidental puncturing .
Cleaning, disinfection and sterilisation
Definitions
Cleaning
Cleaning is the
removal of visible
dirt and visible
and invisible organic
material in order to prevent
micro-organisms being able to remain, multiply and spread.
Disinfection
(Thermal or chemical) disinfection is the reduction in the
number of micro-organisms (bacteria,
mould or viruses)
on lifeless surfaces
and on intact
skin and mucous membranes to a level that is regarded
as acceptable.
Sterilisation
A process that kills or deactivates all the micro-organisms
on or in an object in such a way that the risk of the presence of living
organisms per sterilised unit is smaller than one in a million.
Disinfecting or sterilising equipment?
There are three distinct categories with regard to the
treatment of equipment in order to make
it suitable for reuse:
critical, semi-critical and
non-critical use. The
table below sets out the application of these categories and the method
of decontamination.
Table 1: Treatment of equipment to be reused
Disinfection
Disinfection
should be limited
to situations in
which sterility is
not required but in
which cleaning alone
does not sufficiently
reduce the level
of contamination. If
disinfection is necessary,
thermal disinfection is
preferred. Thermal disinfection
is
carried out using water at a temperature of 65 - 100°C or
using steam. Refer also to the
WIP guideline: Policy
on cleaning, disinfection
and sterilisation. For
surfaces and
objects that are
not resistant to
high temperatures chemical
disinfection should be
chosen. Cleaning should
always precede thermal
and chemical disinfection.
The
instrument washing machines combine machine cleaning and
thermal disinfection.
The following remarks are important for the correct
application of disinfection:
- before disinfection always clean well first
- use chemical disinfection only in
situations set out in the guideline
- use only legally permitted disinfectants
(see below)
- dilute
and dose in
accordance with statutory
instructions as stated
on the
instruction leaflet or the label.
Disinfectants
There are four
laws in The
Netherlands that govern
the use of
disinfectants in a
medical environment, depending on the application area of
the disinfectant. These are:
the Medicines Act,
the Medical Appliances
Decree, the Pesticide
Act and the
Commodities Act. Disinfectants
that are permitted
within the framework
of the first
three acts referred to above can be recognised by their RvG
number, CE marking and
N number of the Board for the Authorisation of Pesticides.
The following disinfectants are eligible for use in dental
practice:
- Alcohol
Alcohol is used for disinfecting skin and hands. Refer to
the WIP guideline: Hand
hygiene.
70% alcohol without
any additives is
used for disinfecting
small surfaces and
objects.
Duration: wet the surface well and leave to dry in the air;
in the case of immersion
leave for 10 minutes.
- Chlorine preparations
250 ppm of chlorine can also be used for surface
disinfection.
For surfaces that have been contaminated with blood or other
bodily fluids a 1,000
ppm of chlorine
solution is used (250 ppm = 0.025% and 1,000 ppm = 0.1% of
free chlorine).
Duration: wet the surfaces well and leave to dry in the air.
- Peroxides
Hydrogen peroxide, peracetic acid and sodium perborate are
used. Peracetic acid is
permitted as an
instrument disinfectant and
sodium perborate as
a disinfecting
storage fluid in case cleaning is delayed for some time.
Peroxides are corrosive for
a lot of materials including non-eloxated aluminium, brass,
rubber and textile.
Sterilisation
Sterilisation is required
for critical equipment,
substances, etc. that
come into
direct contact with sterile tissues or organs.
The
sterilisation of equipment
that is intended
for reuse takes
place in a
steam
steriliser.
Steam sterilisers (autoclaves)
The steam steriliser should be suitable for the intended
use.
The supplier should
be asked if
the equipment provided
is suitable for
the
instruments likely to be sterilised.
Steam
sterilisers (autoclaves) can
be bought in
various sizes and
types. Particularly
important for the
steam-sterilisation process is
the removal of
air from the
steam
steriliser, hollow instruments
and packaging; as
well as the
drying of sterilised
products. These processes are described in sections 7.4.1.1
and 7.4.1.2.
Removal of air from steam steriliser, hollow instruments and packaging
The presence of air obstructs
the sterilisation process.
The following principles
are
mostly used to remove the air from the steam steriliser.
- Removal of air through displacement with
steam
This principle is
used in simple
autoclaves and pressure-cookers. Steam
is
produced in the steam steriliser room by boiling water; the
pressure in the steam
steriliser room increases
somewhat. The steam
mixes with the
air in the
steam
steriliser room and
escapes from the
steam steriliser room
via a ventilation
opening. The longer the boiling and ventilation, the more
air is forced out of the
steam steriliser room
until there is
virtually pure steam
in the steam
steriliser
room. The pressure
then continues to
increase to 1
or 2 bar,
whereby the
sterilisation temperature of 121°C or 134 °C is reached. The
major advantage of
this principle is the simplicity and the consequential low
costs for which a steam
steriliser can be produced. However, the disadvantage of
this is that the air cannot
be removed from hollow objects.
- Removal of air using a multiple deep vacuum
This is the most effective way of removing air, not just
from the steam steriliser
room but also
and - in
particular - from
hollow instruments. The
air is actively
removed from the steam steriliser room and the products
using a vacuum pump.
When the air has been removed, the steam can simply
penetrate into the hollow
instruments. The major
advantage of steam
sterilisers that use
a fractionated
vacuum is that they can sterilise a large range of
instruments.
The types of air removal described here are the two
extremes. There are more ways of
removing the air from the steam steriliser room and the
load. All types of air removal
can in theory
be used; however,
the suitability depends
on the instruments
to be
sterilised. The manufacturer of
the steam steriliser
should carry out
tests to
demonstrate the suitability of the sterilisation process for
the instruments.
N.B. A common practice in the Netherlands is the use of a
3-minute process at 134°C,
or a 15-minute process at 121°C.
Drying the sterilised products
The laminate in
which the instruments
are packaged should
be dry when
the steam
steriliser door is opened. Wet packaging lets bacteria
through, which means that the
contents will not remain sterile. The products can be dried
in the steam steriliser using
a vacuum pump or by blowing filtered air through them (for a
long time).
Instruments
that need to
be sterile (as
they are used
to puncture mucous
membranes)
should be sterilised
packaged and stored
packaged after the
sterilisation process; therefore, the steam steriliser
should be capable of drying the
packaging and the contents at the end of the sterilisation
process.
Validation
The manufacturer should have demonstrated the suitability of
the steriliser for the
intended application.
Validation by the
user is required
if the user
wants to sterilise
instruments or
products that fall outside the intended application of the
steriliser.
Periodic
maintenance of the steam steriliser
should be carried
out in accordance
with the manufacturer's or
importer's instructions. Maintenance
should be
followed by simple control measurements to guarantee the
proper functioning of
the steriliser.
The range and development of instruments used in dental
practice is limited, stagnant
and unvaried between the different practices. The range can
be well estimated by the
manufacturer of the steriliser, and should be taken into
account during the design of
the steriliser. The
application and the
limitations of the
steriliser should be
clearly
stated. If the
user merely uses
the steriliser for
the application stated
by the
manufacturer, an
extensive validation - such as that carried out by hospitals - is not
necessary;
periodic maintenance followed
by control measurements
is sufficient.
Guidelines are currently being prepared by the standards
commission on Sterilisation
and Sterility.
Methods to clean, disinfect and sterilise instruments
Cleaning
The instruments should be cleaned before the disinfection or
sterilisation process;
great care should
be taken with
the inside of
hollow objects. The
inside can be
cleaned using inter-dental brushes or a water pressure gun.
The instruments should be properly dried after cleaning.
Sterilisation of instruments in category A (see Table 1).
Separate
instruments should be
packaged before they
are placed in the
steam
steriliser.
Separate instruments are best packaged in laminate bags that
are specially intended for
steam
sterilisers. The laminate
bags should meet
the requirements set
out in NEN-
EN868-5 (Packaging material and systems for medical devices
to be sterilised - Part 5:
Hot-sealable
laminate bags and
hot-sealable laminate on
a roll manufactured
from
paper and plastic
film - Requirements and test methods). There are various sizes of
laminate bags, which should be sealed; and there is laminate
on a roll, which should be
sealed on both sides. It is not enough to close the laminate
bags by folding them over
unless bags with an adhesive strip are used. Sets and sharp
or delicate instruments can be
packaged and sterilised
in wire baskets
with a single
or double layer
of 'non- woven' around
them. Sheets of
'non-woven' should comply
with NEN-EN868-2 (Packaging
material and systems for medical devices to be sterilised - Part 2: Sheets of
packaging
material for sterilisation requirements and
testing methods). Further
information about the method of packaging using sheets of
'non-woven' is given in the
NEN guideline R3210
(Packaging of medical
devices to be
sterilised in institutions
and sterilisation companies).
If there is no indicator strip on the packaging material, a
piece of indicator tape
should be attached. This indicator strip (or tape) can
prevent confusion with non-
sterilised instruments.
After completion of
the disinfection process,
hands should be
washed or rubbed
with hand alcohol before the instrument washing machine is
emptied.
There should be a clean area for the load that comes out of
the steam steriliser.
The load should be left to cool for at least half an hour
after sterilisation.
The sterilised instruments should be stored in their
packaging in a clean, dry, dust-
free place.
A sticker should
be attached to the laminate
side of the
packaging stating the
sterilisation date and the date until which the sterility is
guaranteed.
The shelf life of packaged sterilised products is six months
as long as the storage
of the sterilised products is in closed drawers or
cupboards.
Sterilised
packaging is vulnerable.
The following things
should be taken
into consideration.
- Do
not write on
the packaging; instead,
attach an pre-written
sticker to the
laminate packaging. A pen will easily puncture the paper or
the laminate.
- Do
not make bundles
of laminate bags;
therefore, do not
use staples, paper
clips or elastic bands.
- Do not cram laminate bags into cupboards or
drawers.
- Do not store laminate bags in places where
they could get damp or wet, such
as on the kitchen sink unit.
Sterilisation of instruments in category B (see Table 1).
If the decision
to sterilise is
taken, the sterilisation
should be carried
out in the
same way as
the sterilisation of
instruments in category
A, with the
difference
being that these instruments do not need to be packaged.
There should be a clean area for the load that comes out of
the steriliser.
These instruments should be stored in a clean, dry,
dust-free place (e.g. in a closed
cupboard or drawer) after sterilisation.
Thermal disinfection of instruments in category B
Thermal disinfection should be carried out in an instrument
washing machine that
is designed in such a way that the inside of instruments
with hollow spaces is also
cleaned and disinfected adequately. This machine cleans and
disinfects in a single
process. Specifications should comply with NEN-EN-ISO
1588-3-1.
After completion of the disinfection
process, hands should
be washed or
rubbed
with hand alcohol before the instrument washing machine is
emptied.
There should be a clean area for the load that comes out of
the instrument washing
machine.
The disinfected instruments should be stored in a clean,
dry, dust-free place.
Disinfection of instruments in category C ( see Table 1)
Instruments in category C that are also used for category A
or category B should
be treated as instruments in category A or B.
Although this is not necessary for instruments in category C, this avoids a
risky
misunderstanding.
Instruments that are
used only for
category C should
preferably be cleaned
and
thermally disinfected in an instrument washing machine.
If thermal disinfection
is not possible
because instruments are
resistant to this
procedure, the instruments should be cleaned and properly
dried, then chemically
disinfected by being
immersed for 10
minutes in 70%
alcohol; they should
subsequently be dried in the air.
The alcohol container
should be closed
off with a
lid. The alcohol
should be
refreshed daily. The container should be emptied, cleaned,
dried and then refilled
with alcohol.
Hands should be
washed or rubbed
with hand alcohol
before the disinfected
materials are touched.
The disinfected instruments should be stored in a clean,
dry, dust-free place.
Methods to clean and disinfect other instruments
When dental (extraction) equipment is bought, the
possibility of being able to clean it
should be an
important consideration. Smooth
surfaces, smooth hoses
and foot
operation of chair, treatment unit and waste bucket contribute
to the reduction in the
risk of contamination and make good cleaning possible.
The treatment chair
The treatment chair should have as many smooth surfaces as
possible.
The chair should
be cleaned using
water and a detergent immediately
after it
becomes visibly contaminated and on a daily basis at the
very minimum.
If there are splashes of blood on the chair, these should be
immediately removed
with a tissue;
then the cleaned
surface should be
disinfected with 70%
alcohol.
When purchasing a chair, it should be checked that the chair
material is resistant to
disinfection agents containing 70% alcohol.
Handles
The handles of
lamps, X-ray equipment,
treatment units, touch-control
panels,
timer buttons, etc, that are touched during the treatment of
the patient should be
disinfected with 70% alcohol after the completion of the
treatment. If the handles
are visibly contaminated, they should be cleaned with water
and a detergent before
they are disinfected.
An alternative to this is to wrap the handles in disposable
plastic film and replace
this after each patient.
If this is not possible, the handles can also be replaced
and thermally or chemically
disinfected.
Dental tray
The use of a disposable dental tray is preferred.
A non-disposable tray should be disinfected after each
patient with 70% alcohol. If
the tray is
visibly contaminated, this
should first be
cleaned with water
and a
detergent.
An alternative to cleaning is to cover the tray with
protective waterproof material;
subsequently, this need only be disinfected and changed.
Multi-function syringe
The tip of the multi-function syringe should not be reused.
After each patient, the multi-function syringe should be
rinsed for 10 seconds with
water and air. The used tip of the syringe should be removed
before rinsing.
The outside should be disinfected with 70% alcohol after
each patient.
Holders
The holders of rotating instruments, extraction hoses,
multi-function syringes, etc.
should be disinfected
with 70% alcohol after
each patient. In
the case of
visible
contamination,
this should be preceded by
cleaning with water
and a detergent.
Only after disinfection of the holder should the disinfected
instruments be returned
to this. The order this occurs in is very important.
Extraction unit
The extraction hose should be briefly rinsed with clean
water after each patient.
The extraction hoses should be cleaned at the end of every
day by sucking up a
detergent in warm water through the hoses.
The choice of detergent depends on the manufacturer's
instructions. If the wrong
detergent is used,
the formation of
foam can result in problems
occurring in the
extraction unit's motor.
When the screen or the hoses of the extraction unit are
cleaned or replaced, there is
always the risk of splashes.
Gloves (rubber), mask and protective glasses should be worn
when the amalgam
separator is cleaned or replaced.
Spittoon
The spittoon should be properly rinsed with water after
every patient. If necessary
(if it is
visibly contaminated), first
left-over impression material,
etc. should be
removed and then the spittoon should be cleaned with a
tissue using water and a
detergent.
Other dental equipment
The operating controls that are touched should be cleaned
after use with water and
a detergent, and then disinfected with 70% alcohol.
The (soft) laser should be fitted with replaceable tips,
which should be thermally
disinfected after use. The lightstick should be thermally
disinfected and the lamp
should be disinfected with 70% alcohol.
Hand pieces and other intraoral instruments
As a result of the technical design of hand pieces and other
intraoral instruments, there
will be contamination
of the inside
of these pieces
during use. Consequently,
it is
necessary to clean these then to disinfect or sterilise them
after use for each patient.
The cleaning of hand pieces and other intraoral instruments
requires special attention.
The rinsing of these, as is done before sterilisation,
cannot be regarded as cleaning. In
addition to the removal of any blood and saliva, good
cleaning means the removal of
any remaining oil. This requires treatment with a detergent.
After
sterilisation or thermal
disinfection, the hand
pieces and other
intraoral
instruments can be oiled. Only by following the steps -
cleaning, thermal disinfection
or
sterilisation, and oiling
- in this
order can there
be sufficient certainty
that the
handpiece is microbiologically safe.
There is special equipment for the cleaning, disinfection or
sterilisation and oiling of
hand pieces and other intraoral instruments. The purchase
and use of this equipment is
strongly recommended, also for reasons of microbiological
safety. This also saves on
maintenance costs and ensures that the hand pieces and other
intraoral instruments last
longer.
Administrative equipment
Administrative equipment should preferably be outside the
splash zone.
Computers, telephones and other office equipment should be
cleaned domestically.
Keyboards and mice can best be protected with a flat,
smooth, plastic cover that is
easy to clean and to disinfect or can be replaced.
If this equipment is touched with contaminated hands or
gloves during treatment, it
should also be disinfected after treatment.
Animals and plants
The presence of
animals and plants
is not permitted
in the critical
area .
Exceptions may be made for guide dogs.
Methods to clean and disinfect areas and bathrooms
Cleaning frequency
The non-critical areas should be cleaned on a weekly basis
at the very minimum,
and the semi-critical and critical areas daily.
Pedal bins and waste-paper baskets should be emptied daily.
Method for cleaning critical and semi-critical areas
'Dry'cleaning
should be carried
out as much
as possible, with
a duster for
example.
Any contamination with organic material should be removed
for example with a
tissue before wet-cleaning can be carried out.
An alkaline cleaning agent is recommended for the daily
cleaning of bathrooms.
For the prevention
and removal of
limescale on sinks
and toilets an
acidic
(decalcifying) agent is recommended.
Disinfection
In general cleaning does not need to be followed by
disinfection.
If blood is
spilt on surfaces,
furniture or objects,
the contaminated spot
should be
immediately
cleaned and then
disinfected with 70%
alcohol, or with
1,000 ppm of
chlorine. Large surfaces cannot be disinfected using alcohol
because of the risk of fire.
The contaminated spot should be dried in the air after
disinfection. Prior cleaning is
required as disinfectants are to some extent rendered
ineffective by organic material
such as blood (proteins).
Maintenance of the cleaning and disinfection material
Disposable materials should be used as much as possible.
Cleaning material that is reused should be cleaned, dried
and cleared away daily
after the work has been carried out. This helps to prevent
cleaning being carried
out with contaminated
objects and the
opposite result being
achieved: an even
greater contamination.
If brushes are
required, plastic brushes
should be used
as wooden brushes
are
difficult to clean.
If a brush is used for cleaning an item that is potentially
contaminated with blood,
the brush should
be disinfected after
cleaning for at
least five minutes
using a
1,000 ppm of chlorine solution, then rinsed, dried
completely in the air and stored
dry.
If a bucket is used for cleaning an item that is potentially
contaminated with blood,
the bucket should be disinfected after cleaning for at least
five minutes using 1,000
ppm of chlorine.
Disposable
absorbent cloths should
be used. If
these are reused,
they should be
washed in a washing machine.
Sponges and chamois
leathers may only
be used for
cleaning of windows
and mirrors.
Removal of waste
Household waste should be put out for the refuse collection service in the usual
way.
Material that is contaminated with blood should be placed in
a sturdy plastic bag
before it is deposited in the dustbin.
Full needle containers are seen as waste that has a risk of
infection; therefore, they
may not be put out with the normal waste. The best thing to
do is to hand them
over as chemical waste (using an environmental box).
The content of
screens and extraction
units, and left-overs
from the amalgam
separator should be thrown away as chemical waste.
Safe working practices in dental practice
General
The dentist and
the employees should
adopt safe working
practices and pay
ongoing attention to the prevention of infection; in other
words, in accordance with
the 'best practice' rules of dentistry.
Treatments should be carried out in such a way that the risk
of contamination for
the dentist, patient, employees and workplace is minimised.
The underlying notion
for this is that work should be carried out with assistance.
Other important conditions
are the organisation
of the practice,
the ergonomic
layout of the practice, the correct routing of clean and
contaminated equipment, a
tidy workplace, and application of this guideline.
The work area
The optimum separation of 'clean' and 'unclean' aspects -
such as the layout of the
practice, the materials, the routing and the treatment - is
an essential basis for hygienic
practices.
The areas in the dental practice should be categorised as:
- critical areas (treatment room, laboratory,
area where the instruments are cleaned
and disinfected)
- semi-critical areas (toilets)
- non-critical (public) areas (entrance,
corridor, office, waiting room).
Layout
There should be
separate areas within
the dental surgery
for treatment and
administration;
as well as
for cleaning, disinfection
and the sterilisation of
equipment and materials.
Furnishing
The treatment room
should have sufficient
worktop surfaces, with
a clear
separation between 'clean' and 'unclean'. The hand-washing
unit should always be
located on the 'unclean' worktop.
The areas for cleaning, disinfection and sterilisation
should be divided into a clean
and a contaminated area.
Cleaning and disinfection should take place in the
contaminated area; packaging
and sterilisation should take place in the clean area.
During furnishing, attempts should be made to ensure that
all the surfaces can be
cleaned easily and properly.
Smooth surfaces without seams and cracks are preferred as
these can be cleaned
more easily.
As little separate
equipment and material
as possible should
be placed on the
worktops.
Equipment and materials
that are used
only occasionally should
be
stored in closed cupboards.
This reduces the risk of contamination and means there is
less to be cleaned.
Clean and sterile equipment and materials should be stored
in closed cupboards or
drawers.
Clean, dry cupboards are required for the storage of
equipment, and there should
be sufficient room
in these cupboards
to store the equipment
separately. An
overfull drawer or
cupboard causes crumpled
packaging, which can
cause hair
cracks in the
packaging that may
result in the
sterility of the
contents being
affected.
The treatment unit
There are two major problems with regard to the treatment
unit: contamination of the
inside caused by a reflux of water into the system when the
spray water feed is turned
off; and a reduction in the microbiological quality of the
water because it stagnates in
the pipeline.
Reflux
A treatment unit should have a device that prevents
the reflux of water
in the pipes
(anti-retraction valves).
Stagnancy of water in the pipes
Stagnancy of water (at night and at the weekend) causes the
formation of a biofilm on
the inside of the plastic pipes of the unit and the growth
of various bacteria, including
Legionella . Rinsing these pipes achieves a 10-fold -
20-fold reduction in the
number of distally forming bacteria.
In the morning and before the first treatment, all the pipes
running from the unit to
the instruments (multi-function syringe,
airotor, micromotors, assistant's
multi-
function
syringe, cavitron) should
be rinsed; and
it must be
ensured that all
the
instruments/openings are separately rinsed through for at
least 30 seconds.
The used pipes, without the hand pieces and other intraoral
instruments, should be
rinsed through for at least 10 seconds between
consultations. This is not necessary
if instruments with anti-retraction valves are used.
Disinfecting the pipeline system and/or adding a
disinfectant to the unit water results
in a water
quality that in
many cases meets
the required bacteriological standard
of
<200 kve/ml [24-30].
When a new unit is purchased, it is recommended that a unit
be chosen which has an
integrated,
often semi-automatic water
disinfection system. These
modern units
usually guarantee an easy, reliable disinfection of the water
and the pipes. Units with
this kind of system should be fitted with a reflux device
(BA safety device) to prevent
the water flowing back into the network (NEN-EN 1717).
Units that are not yet ready for replacement can be
disconnected from the water pipe
and fitted with a bottle that makes it possible to (manually
or automatically) disinfect
the bottled water and, thus, the water in the unit's pipes.
Compressed air in the unit
should then be used to move the water-plus-disinfectant from
the bottle into the pipes.
In general, disinfectants
with hydrogen peroxide
or preparations based
on peroxides
produce good results [26]. The concentration of the hydrogen
peroxide in the bottled
water is around
300 ppm (0.03%).
This can be
checked using peroxide
test strips.
Pipes on units
with a bottle
device can also
be disinfected by
leaving a special
disinfectant in the pipes over the weekend. Ordinary tap
water can then be used in the
bottle during the week.
Aerosols
The spread of aerosols should be kept to a minimum with the
help of an effective mist extractor.
Other materials
Hot-water bath
The temperature of
the water in
the hot-water bath
used to melt
wax should be
raised to 95°C for five minutes at the end of each working
day, as the water is a
potential source of contamination.
At the end of the working week, or if the bath has not been
used for over 24 hours,
it should be emptied after boiling.
To prevent contamination
of the water,
no hands should
be placed in
the water.
Wax sheets should be placed in the bath using tweezers and
taken out again using
tweezers.
Material that has been in contact with a patient (objects or
wax) should never be
placed (again) in the water bath.
Hydrocolloid conditioner
The hydrocolloid impression
material should be
placed in the
thermostatically
controlled water bath (temper-bath) in the tube, and not on
a spatula.
This prevents the
impression material being
contaminated by the
conditioner
water.
Materials and stocks
Materials such as rolls of cotton wool, pellets of cotton
wool and articulation paper
should be stored and covered in such a way that it is
impossible for these materials
to be contaminated in the case of aerosol formation during a
treatment.
For each treatment
only the materials
required for this
treatment should be
prepared. Unused materials
that have been
within the splash
zone during the
treatment are regarded as having been used during the
treatment.
Drills
The drills should
be stored in
such a way
that they cannot
be contaminated by
splashes or aerosols during the treatment.
For each treatment, the drills required for this treatment
should be prepared.
X-ray equipment
The X-ray equipment may be operated with used gloves as long
the parts touched
are disinfected with 70% alcohol following the end of the
treatment.
The packaged image should be rinsed with tap water before it
is inserted into the
developer.
This is not necessary if a system is used that has a
separate protective film around
the image.
Parts of the
developer that have
been touched should
be disinfected using
70%
alcohol.
Digital X-ray equipment uses a sensor that is connected to
the computer via a cable or
phosphorous plates.
The sensor is used with a sleeve; this should be put in the
waste after use.
The phosphorous plate is used with a sleeve that should be
disinfected using 70%
alcohol after use;
the sleeve should
then be removed
and put in
the waste. The
phosphorous plate can now be read in.
Impression material
Before impression material can be sent off, it should be
cleaned using water. Then
the impression should
be immersed in
0.1% hypochlorite for
five minutes. The
impression should then be rinsed under the tap and packed in
a plastic bag.
No soap should be used for the cleaning as this can
adversely affect the quality of
the impression.
Pieces of work that come from a dental laboratory
Pieces of work
from a dental
laboratory should be
rinsed and disinfected
using
70% alcohol before they are tried or fitted.
Pieces of work that are returned to a dental laboratory
should be disinfected in the same way as impressions.
Surgical interventions
An assistant should always be present when surgical
operations take place. Sterile
operations should be carried out in an independent treatment
room that meets the
requirements set out in the WIP guideline: Circumstances
during (minor) surgical
and invasive procedures (Tables 2 and 3).
The dentist and assistant(s) should wear (a) clean
protective jacket(s) and the other
personal protective equipment.
The patient's face should be covered with a sterile cloth
(also a sterile area).
In the case of surgical operations, sterile equipment and
sterile materials should be
used that have been laid out in a sterile area.
The rotating instruments
should be connected
to an external
water-cooler that is
supplied with sterile water or a sterile physiological salt
solution.
Sterile water or
a sterile physiological
salt solution should
always be used
for
rinsing the wound area.
