Article_7_3_2-1
COMMUNITY DENTISTRY www.stomaeduj.com
INFLUENCE OF THE COVID-19 PANDEMIC ON DENTAL
Original Articles
PRACTICE: WHY MEASURES SHOULD BE TAKEN -
THE EXPERIENCE OF AN EUROPEAN UNIVERSITY
HOSPITAL (PART 1)
Constantinus Politis1a* , Annette Schuermans2b , Katrien Lagrou3c , Mia Vande Putte4d , Jean-Pierre Kruth5e
1
Department OMFS, Department Imaging and Pathology, Faculty of Medicine, Leuven University Hospitals, Leuven, Belgium
2
Department of Hygiene, Infection Control and Epidemiology, Faculty of Medicine, Leuven University Hospitals, Leuven, Belgium
3
Department of Laboratory Medicine, Faculty of Medicine, Leuven University Hospitals, Leuven, Belgium
4
Hospital Hygiene and Infection Control Department, Faculty of Medicine, Leuven University Hospitals, Leuven, Belgium
5
Wet Engineering Department, Technical Service, Faculty of Medicine, Leuven University Hospitals, Leuven, Belgium
a
MD, DDS, MM, MHA, PhD, Full Professor & Chairperson OMFS; e-mail: constantinus.politis@uzleuven.be; ORCIDiD: https://orcid.org/0000-0003-4772-9897
b
MD, PhD, Professor; e-mail: annette.schuermans@uzleuven.be; ORCIDiD: https://orcid.org/0000-0002-0998-8241
c
PharmD, PhD, Full Professor KU Leuven; e-mail: katrien.lagrou@uzleuven.be; ORCIDiD: https://orcid.org/0000-0001-8668-1350
d
Infection Control Practitioner, Expert of the Higher Health Council; ICP; e-mail: mia.vandeputte@uzleuven.be;
ORCIDiD: https://orcid.org/0000-0003-0556-5345
e
Eng, Ir; e-mail: jean.kruth@uzleuven.be; ORCIDiD: https://orcid.org/0000-0003-0362-8875
ABSTRACT https://doi.org/10.25241/stomaeduj.2020.7(3).art.2
Introduction The COVID-pandemic does not leave the dental practice unattended. The objective is to
analyze why the COVID-19 pandemic urges changes in daily dental practice in the Belgian context.
Methodology The Leuven University Hospital’s view is based on Belgian and Leuven University data and
existing guidelines concerning hygiene measures in dental practices. The approach chosen is a narrative
qualitative approach.
Results Although no transmission of COVID-19 has been reported in Belgian dental practices, the number
of health care workers infected and deceased urges for safety measures.
Conclusions In the absence of a vaccine and of reliable data about the infectivity of droplet and droplet
cores, dental procedures causing aerosol should be considered as possible sources of viral spread when
treating contagious patients, symptomatic or asymptomatic.
KEYWORDS
COVID-19; Aerosol; SARS-2-COV; Personal Protective Equipment; Respirator.
1. INTRODUCTION an answer to the question why measures should be
taken by the dental community (part 1 of the manu-
After the outbreak of COVID-19 in Wuhan, China, the script) and which measures should be taken in the
virus spread to the rest of the world and on March general dental practice based on the experience and
11th, 2020, the COVID-19 pandemic was formalized the guidelines issued at Leuven University Hospitals
by the World Health Organization. On March 18th (part 2 of the manuscript).
2020, the lock-down was decreed in Belgium and
many dental practices decided to carry out only ur- 2. METHODOLOGY
gent treatments. A gradual reopening from 18.5.2020
was again possible thanks to guidelines from Scien- In contrast to the flu, the COVID-pandemic has
sano concerning the organization of the dental prac- caused massive overload of the hospital system in
tice. The government provided with an additional different European countries (Italy, Spain). The dis-
20 € per treated patient up to maximal 200 patients ruptive nature of the pandemic urges an analysis
per month as from March 1st – December 31st 2020. of the chain of transmission and its translation into
This manuscript (in two parts) is intended to provide daily dental practice. There is a substantial differ-
OPEN ACCESS This is an Open Access article under the CC BY-NC 4.0 license.
Peer-Reviewed Article
Citation: Politis C, Schuermans A, Lagrou K, Vande Putte M, Kruth JP. IInfluence of the COVID-19 pandemic on dental practice: why measures should
be taken - the experience of an European University Hospital (part 1). Stoma Edu J. 2020;7(3):163-174.
Received: September 13, 2020; Revised: September 18, 2020; Accepted: September 20, 2020; Published: September 21, 2020
*Corresponding author: Prof. Dr. Constantinus Politis, MD, DDS, MM, MHA, PhD; Full Professor & Chairperson Oral & Maxillofacial Surgery
Kapucijnenvoer 33B, BE-3000 Leuven, Belgium
Tel. +32 16 341780; Fax: +32 16 332437; e-mail: Constantinus.Politis@uzleuven.be
Copyright: © 2020 the Editorial Council for the Stomatology Edu Journal.
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Original Articles number of surgical procedures in the oro-maxillo-facial
department
(local anesthesia - IV sedation - general anaesthesia)
800
700
600
500
400
300
200
100 Figure 1. The guidelines issued at Leuven
0 University Hospitals caused a significant
1 2 3 4 5 6 7 8 9 10 11 12 impact on the number of executed oral
and maxillofacial surgical procedures,
2019 2020
during and after the lockdown.
Figure 2. The infectious chain in its
simplest form in the COVID-19 virus: the
source (the patient in the infectious
phase) - the susceptible person
(healthcare providers) - the transmission
route (aerosol, direct and indirect
contact).
ence between hospitals and private dental prac- wearing of masks were made obligatory in the hospi-
tices both in guidelines and in exposure to infective tal setting and remained up to date.
micro-organisms. The chain of hygiene in hospitals
offers an excellent framework of existing measures 3. RESULTS
which might fit dental practices in an adapted form.
The Belgian COVID-19 policy is based on a factsheet As a result of these measures none of the health care
which is written by scientists from the Epidemiology providers in the oro-maxillo-facial nor dental depart-
of Infectious Diseases Unit of Sciensano, a Scientific ment got infected with COVID-19. If a health care
Public Health Institute. This factsheet is regularly up- provider for one reason of another tested positive,
dated and integrates knowledge of over 4000 articles contact-tracing was able to determine the source of
published on COVID-19 [1]. The existing guidelines the infection, never being a treated patient. These
for infection control in dental practice in Belgium measures inflicted reduced revenue (Fig.1), while at
date back to May 4th, 2011 and have not been revised the same time incurring new costs (FFP2 masks, RT-
since [2]. In Leuven University Hospitals the policy PCR testing, sanitizing measures. The dental com-
followed was to allow only treatments which could munity and the dental alumni of the Catholic Univer-
not be postponed during the lockdown period. Ever sity of Leuven requested scientific substantiation of
since the lockdown on Marcht 18th, every patient in these measures (PART 1 of the manuscript) and their
need of an aerosol producing intervention or treat- translation into daily dental practice (PART 2 of the
ment was subjected to a COVID-19 RT-PCR test. If manuscript).
the test turned out negative, the planned procedure
was carried out. In case of a positive RT-PCR test the 3.1. The disruptive nature of this pandemic
procedure is postponed for 14 days without renewed There are 4 reasons why the COVID-19 pandemic has
taking of the RT-PCR test. In case of a positive RT- a disruptive effect on dental practice: the raising of
PCR test and medical need for immediate or prompt public awareness through government measures on
treatment, this was carried out in an isolated facility public health hygiene, the characterization of dental
with operating rooms having negative pressure and practice as an increased risk of transmission, the like-
with maximal personal protective equipment includ- lihood that the dentist himself may be infected, the
ing PAPR (Powered Air-Purifying Respirators). At all likelihood of stigmatization in the event of a practice-
times measures of physical distancing, sanitizing and related epidemic. If a country decides to take little or
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Original Articles
Figure 4. An extra-oral fog extraction system.
Figure 3. The COVID-19 virus has a two-layer phospholipid membrane
containing glycoprotein antennae that allow the virus to vaccinate on the
ACE-2 receptors of human cells (the ACE-2 receptor is expressed in lung
tissue, the cardiovascular system, the renal and urogenital systems, the gas-
trointestinal system, the endocrine system, the nervous system).
Figure 5. COVID-19 infection and
disease course: asymptomatic peo-
ple can also be highly contagious
during the incubation period of the
virus.
no action against a growing epidemic in the hope of and CMF doctors - disciplines that are in immediate
obtaining herd immunity, dentists are also not ex- proximity to the patient for more than a few minu-
pected to change their daily practice routine. How- tes - it caused a sensation when ophthalmologist Li
ever, when a country quarantines itself, including the Wenliang from Wuhan alerted the Chinese authori-
outpatient health sector, to prevent the spread of the ties to the consequences of this "new" coronavirus,
epidemic, the dental practice is paralyzed, except only to die of it himself on 7 February 2020 [3].
for urgent treatment. Once all health concerns have The COVID-19 virus will also have an impact on prac-
been re-established, public opinion will be made tice that goes beyond protection against the virus
aware of this infectious agent. For example, there has itself, but rather on its route of transmission, just as
been no national or international public campaign HIV, hepatitis and legionella have done previously
on the flu virus and dental practice has not changed with transmission via blood, surfaces and water. His-
under the influence of the flu epidemics. If someone tory shows that many of the measures that will affect
catches the flu in the waiting room of a dental or outpatient medical or dental practice were imple-
medical practice, it will not cause stigma to the prac- mented much earlier in the hospital sector [4].
tice. However, if several patients in the same practice This will not be different now. As the existing mea-
are infected with HIV or hepatitis virus or MRSA or sures will not disappear, infection control in the den-
Legionella bacteria, this is very stigmatizing when this tal practice will be extended again. Only this time, a
is publicly known. It is therefore not surprising that pair of sterile gloves or a water filter will not suffice,
over the past few decades, possible contaminations even though – at present- no dental health profes-
through water, blood and surfaces have been brought sional working in a private practice in Belgium is
under control through numerous hygiene, disinfec- known to have died in the line of duty from Covid-19.
tion, sterilization and organizational measures. And
certainly, when the dentist and the practice staff can 3.2. The chain of infection
themselves become victims of contamination. In the A three-pronged approach is necessary because
circles of ophthalmologists, ENT doctors, dentists three elements are inseparable: the chain of infec-
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Original Articles
Figure 6a. Evolution of the situation in UZ Leuven between 14.03.2020 and 26.06.2020. The orange (ventilated) and grey (unventilated) bars show
patients admitted to the intensive care unit; the blue bars show patients admitted to hospital wards. During this period COVID-19-positive patients are
separated from COVID-19-negative patients for surgical interventions. Only urgent procedures can be performed on COVID-19-positive patients. For this
purpose, all patients who qualify for surgery will be examined using PCR.
tion, measures to contain the risk of infection and the the viral load mainly affects the respiratory epithe-
time factor throughout the epidemiological phases. lium [10]. The ocular epithelium can also become in-
In its simplest form, the chain of infection is charac- fected with the virus. The virus is excreted through
terized by three basic elements: the source - the route the faeces and faecal-oral transmission is theoreti-
of transmission - the susceptible individual [5]. (Fig. 2) cally possible, but infection through the digestive
Measures to contain the risk of infection are classi- system has not been proven [11,12].
fied according to a certain hierarchy, ranging from Blood-borne transmission has also not been proven
elimination of the source of infection to technical [13]. The virus cannot do anything on its own and is
measures, from organizational measures to personal inactive outside a host. The virus is carried by a drop
protection measures. and it is this drop that can be stopped by mouth
The epidemic has a bell-shaped progression with masks. The virus therefore likes humidity and is be-
an accumulation phase until a peak and then a de- lieved to persist longer in humid conditions [14].
cline that never reaches zero and - in the absence of The virus is lipophilic and can be relatively easily de-
a vaccination programme - can lead to new local or activated with 75% ether and many disinfectants:
generalized outbreaks [6]. Depending on the phase alcohols (ethanol 70% or isopropanol 70-80%), io-
of the epidemic, the impact on dental practices var- dine 0.5%-1% (iodized alcohol, iodophors such as
ies. The health policy choices that the country makes povidone-iodine), chlorinated compounds such as
throughout these phases also have a major influence sodium hypochlorite 0.1% (bleaching javelin), per-
on the overall picture. oxyacetic acid, hydrogen peroxide (hydrogen perox-
ide from 1%) and also quaternary ammonium com-
3.3. The virus pounds such as ammonium chloride (deterioration
There are 7 coronaviruses that can infect humans, of the lipid membrane) [1,15].
with SARS-CoV-1, SARS-CoV-2 and MERS-CoV Chlorhexidine digluconate is not suitable for the in-
spreading worldwide. SARS-CoV-2 (severe acute re- activation of the COVID-19 virus [16]. Chloroxylenol
spiratory syndrome coronavirus 2) is a respiratory 0.12%-0.24% is only suitable for surfaces but not for
single stranded RNA-virus and is responsible for the the inactivation of viruses on the skin (Dettol wax
COVID-19 pandemic. Scientists in Hong Kong had al- gel) [17]. Benzalkonium chloride is not sufficiently ef-
ready warned in 2007 about this "time bomb", which fective against the corona virus [16].
was triggered in 2020 [7,8]. Physical disinfectants are also suitable: a temperature
The virus is relatively small, about 125 nm (0.125 µm) of 56°C for 30 minutes, UV-C rays are all suitable for
in diameter [9]. It is spherical and its mantle consists inactivation. Thorough hand washing with ordinary
of a two-layered lipid membrane in which antennae soap also dissolves the lipid mantle, which inacti-
of glycoproteins (so-called 'spike proteins') are an- vates the virus, as the soap molecules trap the virus
chored that protrude (Fig. 3) and allow them to con- particles and form micelles [18].
nect to ACE-2 receptors in the respiratory epithelium The virus can only survive for a very limited time out-
(and other cells with ACE-2 receptors). Inside the cas- side a host. It needs a host to survive, multiply and
ing is the viral RNA genome. The entry points are the spread. The ideal host for an epidemic is a host that
respiratory epithelium and the oral epithelium, but remains asymptomatic or does not become (too)
the oral epithelium has a greater washing effect, so sick, that does not develop antibodies and in which
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Original Articles
Figure 6b. Daily overview of the number of positive and negative COVID-19 tests performed at UZ Leuven. In mid-June 2020, the number of positive
PCR tests in asymptomatic patients fell to 1 positive in 1368 patients (0.07%), at a cost of 46.80 euros per PCR test.
the virus can survive and multiply, after which the 3.5. Aerosol
host continues to spread the virus; in short, a host Aerosol is a fine suspension of liquid and solid par-
that is a good carrier and super spreader. ticles. This suspension is responsible for the transfer
of micro-organisms into the air. These particles con-
3.4. Route of transmission sist of droplets or droplet cores. The droplets are by
For dental practice, 3 situations are important in the definition > 5 μm ("Flügge" droplets) and are carried
transmission of the COVID-19 virus [19]. up to 1.5 m away when sneezing and coughing, but
3.4.1. Transmission from the patient to the dentist do not remain suspended in the air due to the heavy
and auxiliary personnel. weight [20]. Droplet cores, on the other hand, are
An infected person can infect the dentist and aux- between 1 and 5 μm in size, remain in the air for a
iliary personnel through direct contact (hands) or long time and are transported over long distances.
indirect contact (surfaces), through drip contamina- Coughing and sneezing can transport particles up to
tion (moisture particles) or through contaminated 9 meters. Droplets and droplet nuclei are both part of
air (drip cores) when coughing, sneezing, talking. the aerosol and can contaminate surfaces [21]. In ad-
Contamination by droplets and droplet nuclei is also dition, an aerosol also contains contaminated water,
called aerosol contamination. The aerosol also con- blood, saliva and solid particles. Breathing also en-
tains contaminated water, blood, saliva and solid sures air circulation when transporting the aerosol.
particles (pieces of scale). There is no transmission An adult breathes 5 to 8 liters of air per minute. This
through blood splashes, needlestick injuries or tap can go up to 70-100 liters per minute with very great
water. effort. The particle size determines the depth of the
3.4.2. Patient transmission to the following patients inhalation route through the nose or mouth. Large
Transmission between patients occurs through indi- particles are captured by the mucous membranes
rect contact with contaminated surfaces, materials of the nose, mouth and oropharynx. Particles < 10
and instruments and by holding contaminated aero- μm are inhalable and can reach the lungs. Finer par-
sols in treatment rooms or through the dentist. ticles < 2.5 μm can penetrate the halves of the lungs
3.4.3. Transmission from dentist to patient (22). Ultrafine particles < 0.1 μm (100 nm) can be ab-
Transmission by an asymptomatic carrier dentist is sorbed directly into the blood stream. COVID-19 vi-
possible by aerosol transfer, by direct or indirect con- ruses penetrate deep into the respiratory epithelium
tact, but it is more likely to be a dentist who still car- via the aerosol but cannot enter the bloodstream.
ries the viral load of a previous patient and transmits Although no clinical studies are available, it is as-
it by direct or indirect contact, not by aerosol transfer. sumed that an aerosol containing the COVID-19 virus
remains contagious for about 3 hours. Modifying fac-
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Original Articles
Figure 6c. Number of COVID-19: percentage of positive tests of all tests performed at UZ Leuven.
tors are the degree of aspiration of the aerosol, the not be considered a "fictitious" risk in the absence
number of air changes in the room, humidity, airflow of hard evidence-based data on aerosols produced
characteristics and room temperature. As a high vi- in dental practices. Aerosol-generating procedures
ral load in infected patients is more often associated include those in oro-maxillo-facial surgery and den-
with a more severe course of the disease, it is rec- tal care : tracheotomy and tracheostomy care; airway
ommended to keep the aerosol viral load as low as suctioning; drainage of abscesses, wound irrigation;
possible. Super spreaders are asymptomatic patients use of ultrasound scalers; use of piezotomy; use of
with a high viral load during aerosol production. The turbines and high-speed hand and angle pieces;
fact that this issue is taken seriously in the medical use of airway syringe ; use of electrocoagulation; in-
world is demonstrated by modified resuscitation pro- spection of the throat or base of the tongue using a
tocols where mouth-to-mouth resuscitation in adults tongue depressor; anterior rhinoscopy; endoscopic
is no longer allowed because the risk of infection is examinations of the naso- or oropharynx; all intu-
estimated to be almost 100%. There is good experi- bations of the nose or mouth; tooth extractions; all
mental evidence that the COVID-19 virus survives in surgical procedures in the mouth, jaws or face [24,
aerosol form for 3 hours on plastic and stainless steel 25]. The possibilities of preventing contamination by
for 72 hours, but less than 4 hours on copper surfa- aerosol production in the oro-maxillo-facial surgery
ces [23]. This is little compared to the Coxsackie virus practice are limited: prior rinsing of the patient with
which survives more than 2 weeks on surfaces and iodophoric water or hydrogen peroxide; use of os-
the Hepatitis B virus which can survive more than 14 teotomes for extraction; use of self-tapping screws.
days in a splash of dried blood on a surface. There is In addition, air and smoke control systems must be
no clinical evidence or in vivo measurements of the used as usual; in hospital operating theatres: nega-
COVID-19 virus in aerosols. There are no known num- tive pressure in the operating theatre; ± 60 air chang-
bers of COVID-19 viruses in aerosols, let alone wheth- es per hour in an operating theatre, smoke extraction
er they are "infectious". On the other hand, however, systems, HEPA filtration and complete cleaning of the
there is overwhelming clinical evidence of doctors, operating theatre between two patients. HEPA filtra-
dentists, nurses who have treated COVID-19 patients tion stands for High Efficiency Particle Air Filter and is
without protection (and sometimes even protected) a filter that physically removes harmful microorgan-
and have fallen ill to a much greater extent than the isms but does not inactivate them [26,27]. In dental
average population. For other viruses as well, serologi- practice, the use of the rubber dam simultaneously
cal monitoring shows that they have more antibodies with the surgical aspiration allows a reduction of ±
against the cytomegal virus (CMV), the Epstein-Barr 70% of aerosols [28,29]. Here too, it is advisable to
virus (EBV), but also against the Legionella bacteria rinse the patient beforehand with isobetadine or hy-
than the general population. In short, aerosols can- drogen peroxide. The use of osteotomes for dental
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extractions is a sensible measure. The use of a hand- VID-19 virus is estimated at 5-6 days, with a range of
Original Articles
pieces fitted with anti-retraction valves is recom- 1-14 days [38]. This is very different from the SARS-1
mended [30]. Ultrasound, piezoelectric and angle virus, which has an incubation period of 2-7 days, but
handpieces should be avoided if a good alternative where the person carrying the virus is infectious only
is available. Here again, air treatment systems will be after showing symptoms. In MERS, infectivity is pres-
used in addition to extra-oral fog extraction systems ent during the incubation period of 2-14 days, but
for aerosols, although the latter penetrate the work- human-to-human infection is relatively limited. SARS
ing field (Fig. 4). The systems that have been known and MERS infection is mainly associated with nosoco-
for a long time in the hospital sector will be used as mial spread, while COVID-19 virus is transmitted by
a basis for achieving germ reduction. It is not known aerosol, contact and possibly fecal-oral transmission
how many COVID-19 viruses are contained in one ml in the community (RNA for the virus has been found
of aerosol, but it is known that 1 ml of saliva contains in the faeces of patients, but actual fecal-oral trans-
about 10 million bacteria and also that 15 minutes of mission has not been demonstrated yet). For all three
unprotected operation corresponds to the inhalation coronaviruses (SARS, MERS, COVID-19), transmission
of 0.014-0.12 μl of saliva per aerosol. The use of at- on emergency health personnel has been detected
ropine for dry mouth has been observed in patients [39, 40]. It is completely unknown how many viral
who drool but not in healthy patients. Hypothetically, particles a person has to inhale in order to become
dry mouth should lead to a reduction in aerosols, but infected. For the Ebola virus, one article on the virus
this is not supported anywhere. is sufficient. For the noro-virus, 10 to 100 virus par-
ticles are sufficient. For the coronavirus, it is assumed
3.6. The patient as the source of COVID-19 virus that 100 to 1000 virus particles are required for an
As soon as the virus enters the patient and is an- infection. A number of host-related factors also play
choring its antenna-like glycoproteins on the ACE-2 a role (diffusion of receptors in the respiratory tract,
receptor of the epithelial cells, the latent phase be- advanced age of the patient, ...).
gins in which the virus must develop a whole pro-
duction chain in order to replicate and release the 3.7. Evolution of COVID-19 disease
newly formed viruses. The latent phase ranges from In general, it can be said that a large number of in-
infection to the release of new infectious virus par- fected patients remain asymptomatical. Depending
ticles and the latent phase is immediately followed on the infected groups (cruise ships, aircraft carri-
by the period of transmissibility or infectivity [31,32]. ers), it is known that between 20 and 60% of patients
This phase is also known as the infectious phase. The with a positive PCR test result were asymptomatic.
exact duration of the latency phase of the COVID-19 For those with a symptomatic course, about 80% will
virus cannot be determined precisely but varies be- mainly have a flu-like viral syndrome characterized by
tween 1 and 4 days. The duration of the transmissibil- fever, dry cough, sore throat and some general symp-
ity period (contagious phase) is also not known with toms. Prodromal symptoms are possible and consist
certainty, but as a guide, a 14-day contagious phase is mainly of a sudden loss of smell and taste [41]. The re-
maintained, with patients who present symptoms for maining fraction of patients with symptoms require
the duration of clinical symptoms being considered hospitalization, with a significant fraction ending up
contagious. The fact is that symptomatic patients in intensive care with a risk of death from pulmonary,
are more contagious than asymptomatic. In some cardiovascular, thromboembolic, renal complications
studies, PCR positivity has been established up to 37 and/or multi-organ failure. These complications are
days [33]. The patient's clinic does not strictly follow not so much considered as an effect of the virus, but
the path of virus replication and therefore does not rather as a host effect on the virus (excessive immune
follow the line between the latent and contagious response with cytokine storm) [42]. Not everyone
phases. The patient clinically follows an incubation has the same risk of developing a serious illness. Ad-
period (first asymptomatic phase) followed by either vanced age, male sex, obesity, high blood pressure,
an asymptomatic or symptomatic evolution, iden- cardiovascular disease, diabetes mellitus, smoking,
tifying a diverse spectrum of diseases ranging from chronic obstructive pulmonary disease, malignan-
mild, moderate, severe, critical to fatal. The incuba- cies, chronic kidney disease, immune incompetence
tion period does not run parallel to the latent phase are considered to be patients at risk for serious dis-
(Fig. 4). The patient starts to be contagious during the ease progression. In some reports, health profession-
incubation period when he or she is not yet aware als are also referred to as "at-risk patients" because
of a disease, in the asymptomatic phase. This means of the high incidence of infection with serious dis-
that simple questioning and examination of the pa- eases and even death [43]. For the dental practice,
tient's symptoms is not sufficient to detect infected the course of the disease is important in order to
patients [34,35,36]. The most important contagious- establish good questionnaires to detect potentially
ness is at the beginning of the disease course, dur- infected patients in time and to measure body tem-
ing the period when symptoms are minimal to mild. perature on arrival at the practice.
During the incubation period, therefore, screening 3.8. RT-PCR screening
tests are used [37]. The incubation period of the CO- As the patient may already be contagious during the
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asymptomatic incubation period, it is necessary, in care centers equipped to treat patients who are posi-
Original Articles addition to the questionnaire, to develop a screening tive for COVID-19 or treatment is deferred for 14 days
test that can detect the presence of viral particles. In and the patient may undergo the aerosol produc-
Belgium, a reverse transcriptase polymerase chain re- tion procedure if they are clinically completely cured.
action test (RT-PCR screening test) has been chosen. This policy can only be justified when the number
A throat or nasopharyngeal swab is taken and the of dental and oro-maxillo-facial surgery procedures
test can detect very small amounts of viral genetic is limited to emergencies. Once the lock is lifted and
material. The detection of viral material is not syn- citizens are allowed to return to the dentist for den-
onymous with infectivity. This test is not immediately tal care, the PCR test is no longer a tool that can be
readable, but requires a procedure in a clinical biolo- used in the event of a very low number of positive
gy laboratory [44,45]. Under ideal circumstances, the results. Figures from the health insurance funds show
sensitivity of this test is particularly high (over 95%). that about 40-50% of members go to the dentist ev-
However, in real life, it is assumed that false negative ery year and that more than half of the patients go
results of up to 30% are detected when testing upper to the dentist for curative care, mainly for the treat-
respiratory tract wipers, for several reasons. Incorrect ment of caries. However, there is also aerosol produc-
sampling is by far the main cause of a false negative tion during extractions, periodontal treatment and
result, followed by the quality of the wipers, transport preventive dental care. In total, more than 2 million
problems, the margin of error of the test itself, and treatments can be carried out. Add to this more than
the presence of too few viruses [46,47]. It is assumed 300,000 oro-maxillo-facial surgery operations per
that these false negative (i.e. truly positive) patients year and it soon becomes clear that a pre-operative
have a low level of infectivity. A PCR test is a snapshot test at 46.80 euros is not realistic, even if there were
in which it is often assumed that the result is valid sufficient test capacity for it. At the Leuven University
for about 48 hours. The guideline at Leuven Univer- Hospital, as of March 11th 2020, every patient in need
sity Hospitals states that a person with a positive PCR of an aerosol producing procedure, receives an RT-
test is considered COVID-19 positive, a person with a PCR testing the day before the intervention. This pol-
negative PCR test is considered COVID-19 negative, icy has been continued and probably will be contin-
and a person who had a positive PCR test 14 days ago ued until cheaper reliable chair-side testing becomes
and has been quarantined since then, and who has available or an approved vaccine becomes available.
not had a fever for at least three days, may continue Without a laboratory test, all that remains is a patient
to be considered negative after those 14 days with- questionnaire. Interrogation does not conclusively
out a new PCR test. The reason why no new PCR test detect an asymptomatic contagious patient, but may
is recommended is that RNA can remain present for a be indicative of recent contact with a person with a
very long time, allowing the PCR test to remain posi- COVID-19 diagnosis. There are also a number of draw-
tive for a long time without proving infectivity [48]. backs to interrogation that allow both false positive
In immunocompromised patients, and after a stay in and false negative conclusions to be drawn. In prac-
intensive care with artificial respiration, it is necessary tice, the dentist will be faced with a situation in which
to wait 28 days after a positive PCR test and a new he cannot be sure whether a patient is contagious or
PCR test is subsequently recommended. PCR tests not with COVID-19. Unlike the influenza virus, which
are logistically cumbersome for clinical biology labo- repeats itself every year, the dentist is forced to take
ratories, are expensive (€ 46.80 in Belgium and € 60 in the necessary measures against the transmission of a
Germany since the end of May 2020) and the testing possible COVID-19 virus in the dental practice.
capacity is limited per country and per hospital. PCR At least until a sufficient part of the population has
testing is particularly useful in communities where been vaccinated against the COVID-19 virus.
COVID-positive patients or healthcare providers are
located (ships, camps, residential care centers, hospi- 3.9. Chains of hygiene
tals). Furthermore, the social cost is only justified in Just as there is a chain of infection, there is also a
the phase of the epidemic when PCR testing actually chain of hygiene to reduce the risk of exposure to
influences local policy (Fig. 6 a, b, c). However, once germs. Here we identify a series of measures and a
the epidemic has passed its peak and a large number ranking of these measures. This set of measures is
of tests are needed to find a positive test in an asymp- usually grouped by sector in guidelines or recom-
tomatic patient, the cost-benefit ratio becomes very mendations.
unfavorable and, in addition to screening, general 3.9.1. Dentistry sector
hygiene and prevention measures as well as contact In 1997, a Belgian guideline for dentistry was devel-
tracing will be used. This has repercussions on dental oped under the title "Hygiene in Dental Practice" by
practice. During a phase of national closure, it is jus- the Ministry of Social Affairs, Public Health and the
tified to state that anyone requiring an aerosol pro- Environment [49]. It stated that "the spread of the
duction procedure must undergo a PCR test. In the Human Immunodeficiency Virus (HIV), the preven-
event of a negative result, treatment can continue tion of infections with the hepatitis viruses (HBV and
with the usual personal protection measures. If posi- HCV) and the increase in cases of Therapy Resistant
tive, treatment is carried out in health care facilities or Tuberculosis (TB) are at the root of the greatly in-
170 Stoma Edu J. 2020;7(3): 163-174 pISSN 2360-2406; eISSN 2502-0285
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creased concern for the prevention of transmission of premises, water and air quality control [4].
Original Articles
infections in medical procedures in hospitals. To date, 3.9.2.2. These standardization measures have long
there are no binding guidelines for measures to be since been supplemented by measures to prevent
applied in the dentist's office. In the absence of any transmission by direct or indirect contact, droplet
form of external control, it is the duty of every dentist and droplet core transmission (aerosol transmission).
to assume his or her responsibility in this respect". They applied only to patients with or suspected of
This publication was followed by the "Infection having an infection.
Control Recommendations during dental care" of 4 These additional measures aim to prevent transmis-
May 2011 issued by the High Council of Health (pub- sion and consist of isolating patients, defining and
lication no. 8363) [2]. The prevention of airborne limiting patient pathways by providing separate
transmission of germs is explicitly mentioned, with routes for staff and visitors, limiting the number of
attention being paid to the use of rubber dam, a contacts with the infected person, the use of dis-
nebuliser, a nasal mask and a face shield, as well as posable products and the application of personal
to rinsing the patient's mouth before any procedure. protection measures also for the person suspected
These recommendations are not legally binding. of infection, as well as strengthening cleaning and
In the Netherlands, the "Guideline on Infection disinfection procedures for the environment and
Control in Oral Care Practices" is regularly updat- equipment (both frequency and products as indi-
ed [50]. This is also based on the same concerns as cated). It seems obvious that a number of measures
above. In the 2016 edition of the Dutch Aerosol Di- which were generally designed for hospital use and
rective it is also stated: "The amount of pathogenic related to the transmission of aerosols will have to be
micro-organisms in an aerosol is strongly diluted by progressively translated into dental practice. It may
water. Therefore, for most interventions, the risk of be possible to progressively review each chapter of
infection due to aerosol contamination is negligible". infection control, but it seems more appropriate to
Perhaps this wording will be changed in a future edi- take an approach closer to the chain of infection de-
tion. In the United States, the Center for Disease Con- scribed above.
trol and Prevention has also updated the 2016 guide-
lines for infection control and prevention in dental 4. LIMITATIONS AND FUTURE AIMS
offices, but states that "dental facilities are generally
not designed to apply all transmission-based precau- The limitation of this paper is that it does not com-
tions (for example, airborne infection precautions for pare two patientgroups and health care providers,
patients suspected of having tuberculosis, measles, one following the guidelines and the other not fol-
or chickenpox) that are recommended for hospitals lowing the guidelines. Future research should de-
and other ambulatory care facilities.” This is clearly a termine the number of COVID-19 virus particles in
guideline that predates COVID-19 [5]. dental aerosols and in the air of the dental practice
3.9.2. Hospital sector in order to quantify the risk of contracting COVID-19
As far as hospitals are concerned, there is no "no com- through droplets and droplet cores.
mitment" choice. Infection prevention and control
manuals in hospitals are more than 1000 pages long 5. CONCLUSION
and there are binding regulations and accreditation
standards that are verified through internal and ex- The COVID-19 pandemic highlighted aerosol trans-
ternal audits of hospitals [51]. The well-known JCI mission in the chain of infection bringing both health
audits and JCI hospital accreditations are an expres- professional and patients at risk. Implementation of
sion of this. Infection control is a set of procedures adequate measures in the general dental practice
and policies to prevent or stop the spread of infec- can be achieved by returning to solutions that have
tions [52]. There are two types of measures: standard already existed for some time in the hospital environ-
measures and transmission control measures. ment and, where possible and feasible, integrating
3.9.2.1. Standard measures have been steadily them into daily practice.
expanded over the past several decades. They relate
to hand hygiene, personal protective measures for CONFLICT OF INTEREST
the health care provider, respiratory hygiene, alloca- The authors declare no conflict of interest.
tion of separate rooms for patients, prevention of the
spread of infections inside and outside the health AUTHOR CONTRIBUTIONS
care facility ("environmental control"), safe injection
techniques, prevention of needlestick injuries, clean- All authors contributed to this paper. CP: contributed to concept
ing and disinfection of instruments and surfaces. The and writing. AS and MVP: contributed to protocol. KL: contributed
standard measures apply to all patients, whether to data gathering and analysis. JK: contributed to critically revising
symptomatic or asymptomatic. Environmental con- the manuscript.
trol can be divided into several categories: waste con- ACKNOWLEDGMENTS
trol, animals in care facilities, washing and bedding,
None.
samples for control and monitoring, disinfection of
Stoma Edu J. 2020;7(3): 163-174 pISSN 2360-2406; eISSN 2502-0285 171
Politis C, et al.
www.stomaeduj.com
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Constantinus POLITIS
MD, DDS, MM, MHA, PhD
Full Professor & Chairperson
Oral and Maxillofacial Surgery Department
Faculty of Medicine
University Hospitals Leuven, KU Leuven
Leuven, Belgium
CV
Dr. Politis is an Oral and Maxillo-Facial Surgeon. He is currently a Full Professor and Chairperson of the Department of OMFS at
Leuven University Belgium. He is an invited Lecturer at EHSAL in Brussels. He graduated from the Catholic University of Leuven
in medicine (MD) and dentistry (DDS), also specializing in oral and maxillofacial surgery at the same university. He defended his
doctor’s thesis on the subject of complications of orthognathic surgery (PhD). He followed additional postgraduate training in
Arnhem (Stoelinga), Aachen (Koberg), Copenhagen (Pindborg), Göteborg (Bränemark) and San Francisco (Marx). He also holds
a master degree in management (MM) and a master degree in Hospital Management (MHM). He is Secretary General of the
Professional Union of Belgian Oral and Maxillofacial Surgeons. He is acknowledged trainer of OMFS trainees. Clinical research
projects include prevention and repair of iatrogenic trigeminal nerve injury, transplantation of teeth and orthognathic surgery.
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Politis C, et al.
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Questions
Original Articles
1. The COVID-19 virus is a(n):
qa. Enveloped virus;
qb. Non-eveloped virus;
qc. DNA-virus;
qd. Double-stranded RNA virus.
2. The least probable route of transmission is:
qa. Contaminated aerosol;
qb. Contaminated respiratory droplets;
qc. Contaminated fomites;
qd. Blood of COVID-19 patients.
3. PC-R testing for COVID-19:
qa. Allows results to be read in 30 minutes;
qb. Has less false positive than false negative results;
qc. Has hardly ever false negative results;
qd. Is only positive in COVID-19 symptomatic patients.
4. The following is not suitable for the inactivation of the COVID-19 virus:
qa. Ethanol 70%;
qb. Sodium hypochlorite 0.1%;
qc. Hydrogen peroxide from 1%;
qd. Chlorhexidine biguanide.
174 Stoma Edu J. 2020;7(3): 163-174 pISSN 2360-2406; eISSN 2502-0285