Biosecurity in Post-Covid-19 Dental Care: An Integrative Review 2 of 13
Oral health professionals work directly in the oral cavity, which is a highly contam-
inated environment, frequently exposing them to a wide variety of bacteria, viruses, fungi,
and other infectious pathogens [6, 7]. However, contact with these pathogens does not
necessarily result in the transmission of an infectious disease to the professional. This is
because the risk of infection depends on several factors, such as the virulence of the mi-
croorganism or its pathogenicity class, the amount of microorganism transmitted, the fre-
quency of exposure [8], and the immunological condition of the contaminated individual
[9]. Therefore, it is important to note that there are several ways of cross-contamination
in the dental environment [10]. This contamination can occur through different routes,
such as direct contact with blood, saliva, oral fluids, or contaminated materials; indirect
contact via instruments, surfaces, infected equipment; contact of the ocular, nasal, or oral
region with droplets; inhalation of aerosols [11, 12]; or through the water from the dental
unit water lines [8].
It should be noted that the water used in dental units is distilled, not sterile, and can
contain a high number of bacteria and opportunistic pathogens such as Legionella pneu-
mophila, Mycobacterium spp., Pseudomonas aeruginosa, and Candida spp [13]. Although
it is a means of pathogen transmission for both the professional and the patient, water is
of utmost importance for viable dental care [8]. In addition to infectious microorganisms,
aerosols can be composed of blood, saliva, dental biofilm, among other residues, and their
infection capacity will depend on the characteristics of these fluids and the presence or
absence of any type of oral infection [6, 7]. Thus, the composition of aerosols varies from
patient to patient, according to the oral cavity microflora and the type of procedure being
performed [10]. Procedures using high or low-speed handpieces, air/water spray syringes,
ultrasonic instruments, lasers, among others, are considered aerosol-generating proce-
dures [14, 15].
Effectively, aerosols can travel a distance of one to three meters from their source [6,
14]. They also have the capacity to remain suspended in the air for a long period until
they settle on a surface or are inhaled by someone [10, 14]. Aerosols result in the trans-
mission of various pathogens from the dental unit water [6], and from the patient's oral
cavity [10]. It is worth noting that several infectious diseases can be acquired through the
ocular region, via contact with blood splashes, respiratory droplets, or aerosols containing
infectious pathogens. Therefore, the American Centers for Disease Control and Preven-
tion (CDC) advises that professionals working in environments where such contamina-
tion may occur, such as oral health professionals, use eye protection, such as goggles or
face shields. This creates a barrier between the eye and these infectious agents [16].
To minimize or avoid cross-contamination during dental procedures, it is essential
that the team uses personal protective equipment (PPE), such as masks, N95 respirators,
caps, gloves, protective goggles, or face shields, among others. This equipment aim to
reduce the exposure of the dentist and their assistants to aerosols, blood droplets, saliva,
among other oral substances and possible pathogens contained in them [17-19]. Due to
the COVID-19 pandemic, the techniques for using PPE and biosafety in healthcare were
reconsidered, with some PPE, such as face shields and respirators, becoming necessary
during clinical practices. Similarly, some biosafety measures were implemented in dentis-
try to protect professionals from possible contamination [18, 20].
Among these newly established biosafety measures are pre-screening of the patient,
which should be conducted before the patient arrives at the dental clinic or office,
through phone calls or messaging apps. Dental appointments should be scheduled with a
set time, with a certain interval between each one. Additionally, patients should be in-
structed to come alone, with an accompanying person permitted only when necessary
[20]. Upon arrival at the clinic, the patient's temperature should be taken. Only people
wearing masks should be allowed entry, the reception chairs should be spaced out to pre-
vent people from sitting too close together, and 70% alcohol should be made available
on-site. It is also important to conduct another screening when the patient arrives at the
clinic, before the appointment, to investigate possible symptoms again [4, 5]. It is assumed
that in addition to all these additional biosafety measures, aerosol-generating procedures