Dental Asia May/June 2020

Clinical Feature
common and are in close contact with
staff. Disinfection of the whole dental
practice to eliminate any droplets and
aerosols contamination are most essential.
COVID-19 can cause infection after twohour
exposures on surfaces and last for nine
days, surviving at 50% relative humidity.
Therefore, it is suggested that a clean and
dry environment in the dental office would
help decrease the persistence of the virus 1, 8, 9 .
Infection control strategies
In order to intercept the infection of
COVID-2019, dentists should have a
better understanding of the virus on its
transmission routes, as well as the protocol
to stopping its spread in the dental office 9 .
1. Identify patients with possible
COVID-2019 infection.
2. All patients must record their body
temperatures before entering treatment,
and fill up a form on their past travel history.
3. Extra protective measures should be
applied to all dental operations. These
include infection control measures that
should be followed by all operators and
staff. Our recommendations are based
on the WHO, CDC Guideline for Infection
Control and the Diagnosis and Treatment
of Coronavirus.
4. It is rare to encounter confirmed COVID-19
patients in general dental offices, since most
of these patients will be under hospital care
until they are tested negative. For patients
with symptoms, seeking dental treatment
is not recommended. Analgesics to prevent
severe pain seems to be the only available
solution, until the patient has been tested
negative.
Non-urgent or elective dental procedures,
particularly those which will generate
aerosols, should be delayed.
5. A 20-second pre-procedural mouth
rinse with either of the following is also
recommended:
• 1% hydrogen peroxide
• 0.2% povidone iodine
• 0.2% chlorhexidine rinse (alcohol free)
• an essential oil mouth rinse (alcohol free) 3 .
6. The following websites are recommended
by different well-known organisations for
dental practitioners for references:
I. WHO (2003a) Practical Guidelines for
Infection Control in Health Care Facilities.
Geneva, Switzerland: WHO.
http://www.wpro.who.int/sars/docs/
practicalguidelines/practical_guidelines.
pdf, accessed 2 August 2004.
II. The concept of ‘Standard Precautions’
which, as defined by the CDC, are a set
of safety measures designed to prevent
transmission of blood-borne infectious
agents, human immunodeficiency virus
(HIV) and hepatitis B virus (HBV). CDC
(2003a) Guidelines for infection control in
dental healthcare settings - 2003. MMWR
52 (No. RR-17).
ADA Interim Guidance for Minimising Risk of
COVID19 Transmission
https://www.ada.org.au/Campaign/
COVID-19
https://www.ada.org/en/publications/adanews/2020-archive/february/ada-releasescoronavirus-handout-for-dentists-basedon-cdc-guidelines
https://www.cdc.gov/coronavirus/2019-
ncov/infection-control/controlrecommendations.html?CDC_AA_
refVal=https%3A%2F%2Fwww.
cdc.gov%2Fcoronavirus%2F2019-
ncov%2Fhcp%2Finfection-control.html
III. United Kingdom Department of Health.
NHS HTM 01-05: Decontamination in
primary care dental practices. 2013 Version.
https://www.chp.gov.hk/files/pdf/the_
basic_protocol_ic_guidelines_for_the_
dental_service_dh.pdf
Personal Protective Equipment (PPE)
The operator and staff should be well
protected with surgical mask or N95, face
shields, disposable gowns, surgical gloves
and hair covers for all dental procedures
according to the guidelines listed by CDC.
In this era of panic and fear, there are
a lot of confusions and misconceptions
existing regarding the use of mask, not only
among the layperson, but also among the
healthcare providers.
On the one hand, masks are not available
for the group at risk, while on the other
hand, those who are not at risk are spending
unnecessary money and energy to procure
these masks.
The difference between a mask and a
respirator is that a mask has a loose fit,
which does not seal the nose and mouth
snugly, while a respirator has a tight seal,
and most of the time, air passes only through
its material after filtration. Examples of
respirators are:
N-95 - capable of trapping 95% of particles
N-99 - capable of trapping 99% of particles
N-100 - capable of trapping 100% of
particles
Respirators are graded according to their
filtration efficiency according to the used
filter type, materials used and additional
features.
Respirators can also be graded in filtration
efficiency as:
P1 (FFP1) - 80%
P2 (FFP2) - 95%
P3 (FFP3) - 99.95%
The oil resistance of respirator can be
further graded as N, R, or P and is usually
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DENTAL ASIA MAY / JUNE 2020