Marcelo Salmazo Castro¹, Ana Virginia Santana Sampaio Castilho¹, Lucas José de Azevedo-Silva², Lorrayne Farias dos Santos³, Eliel Soares Orenha¹ and Silvia Helena de Carvalho Sales-Peres¹*

¹Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Brazil
²Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Brazil
³Bauru School of Dentistry, University of São Paulo, Brazil

*Corresponding Author: Silvia Helena de Carvalho Sales Peres, Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Brazil.

Received: March 15, 2021; Published: April 08, 2021

Abstract

  This systematic review aimed to investigate the COVID-19 biological risk based in knowledge, attitudes and perception of dentists during COVID-19 pandemic and to establish a clinical protocol based on the literature. The protocol was conducted in accordance to PRISMA Statement and registered on International Prospective Register of Systematic Reviews (CRD42020200258). PubMed, Embase and SciELO were systematically searched, using the key terms “coronavirus infections” AND “dentists”. Four articles were selected for qualitative and ten for quantitative analysis. The overall studies reported characteristics of dentists (n = 12,913) who completed survey questionnaires: male (n = 6,690; 51.8%); knowledge: transmission route (n = 1,892; 14.65%), use of personal protective equipment (PPE) (n = 2,418; 18.7%) and signs and symptoms (n = 1,489; 11.5%); attitudes: urgency treatment (n = 2,633; 20.4%), handwashing (n = 5,548; 43%), reducing patients in waiting room (n = 3,020; 23.4%), and use of masks (n = 4,068; 31.5%); and perception: infection risk (n = 2,387; 18.5%). The clinical protocol includes procedures before appointments, correct handling of the operative area, and use of correct PPE. The primary COVID-19 biological risks are infectivity and horizontal transmission. The clinical care protocol in dentistry should be adopted by all dentists to reduce biological risk. Thus, dentists may play an important role in the prevention and interruption of SARS-CoV-2 transmission chain.

Keywords: Coronavirus Infections; Containment of Biohazards; Dentists; Dentistry; Clinical Protocol

Introduction

  Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), an infectious disease characterized by several important systemic disorders, such as pneumonia associated with coronavirus. The main symptoms of the disease are categorized into mild (fever, cough, myalgia, fatigue and sputum) and severe (cyanosis, tachypnea, chest pain, hypoxemia, dyspnea, and require clinical assessment) [1-3]. Most patients have mild symptoms, and in more severe cases, they can progress to pneumonia [4].

  Among healthcare professionals, dental surgeons have been highly exposed to SARS-CoV-2 infection [5-7]. These professionals routinely perform procedures using instruments that generate aerosols (small particles), which can be inhaled within the work environment, exposing both the clinician and the patient to infection. Dental professionals must protect the patients from the spread of all infectious diseases by adopting safe practices in the performance of their work and making dental procedures safe [8].

  According to a scientific report published by the World Health Organization, the SARS-CoV-2 can be transmitted through respiratory droplets from direct contact with an infected person (distance less than 1 m), indirect contact with contaminated surfaces or objects and aerosol produced during procedures performed on infected patients [9]. Hence, dental and health organizations have published recommendations to postpone all elective dental treatments and non-essential procedures and limit services to urgent and emergency visits only.

  Dental health personnel (DHP) should be aware of the transmission mechanisms and infection control procedures, be able to identify patients with signs and symptoms of COVID-19 and have a clear understanding of the characteristics of a dental emergency, an urgent dental care and a non-emergency dental treatment [10].

  There is 100% chance of acquiring the infection when an individual comes in contact with a COVID-19 patients’ saliva; saliva samples can also grow the live virus. Hence, the potential infectivity of saliva must be strongly considered [11]. Thus, dental offices, both in the public and private sectors, are considered as high-risk environments for cross-infection among patients, dentists, and healthcare professionals in the clinical setting. Elective dental treatments and non-essential procedures must be postponed and only emergency care must be provided. Dentists should consider that a substantial number of individuals who do not show signs and symptoms of COVID-19 may be infected and spread the virus [10].

  Therefore, preventive strategies must be improved, especially for dentists, to reduce the risk of acquiring COVID-19 [12]. Currently, one of the main challenges in dental care is the difficulty in identifying infected patients, due to the need for an adequate diagnostic pattern and the possibility of exposure to an asymptomatic patient. Hence, every patient should be considered as an infected individual to the risk of infection. Therefore, this systematic review aimed to investigate the COVID-19 biological risk supported by the level of knowledge, attitudes and perception of dentists during the COVID-19 pandemic. We also propose to create a new clinical care protocol based on the gaps found in the recent literature.

Materials and Methods

  The data in this systematic review were reported according to the National Health Service Centre for Reviews and Dissemination [13] and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement) guidelines [14] based on Cochrane collaboration (www.cochrane.org). The complete work protocol was registered in the International Prospective Register of Systematic Reviews (CRD42020200258). The eligibility criteria were defined in relation to the participants, interventions, comparisons, outcomes, and study design as recommended by the PRISMA Statement. In this systematic review, the following questions were raised: 1) What has been changed in dentistry practice during the COVID-19 pandemic? 2) What level of knowledge does the dentists have regarding the disease? 3) Are the dentists using the correct preventive measures against the spread of coronavirus? 4) What new protocols can be adopted for dental care?

  PubMed, Embase, and SciELO were systematically searched, using the following key Medical Subject Headings terms: “coronavirus infections” AND “dentists”. Furthermore, the reference list was reviewed to identify other potentially relevant studies. The last search was conducted on June 26, 2020.

  As the eligibility criteria, we selected studies in English published in peer-reviewed journals that have addressed the questions in surveys using epidemiological data, reported the protective measures, and discussed the knowledge and the prevention and control practices of dentists during the COVID-19 pandemic. Articles with protocols for managing COVID-19 were also considered. Duplicate publications and articles that did not achieve the objectives of this systematic review were excluded. Similarly, publications without a research protocol such as opinion article, correspondence, editorials and letters were also excluded. Figure 1 shows the procedure of the literature search.

  Three investigators participated in each phase of the review and independently screened the titles and abstracts of the articles obtained during the search based on the inclusion criteria. The investigators screened the full text reports and determined if they met the inclusion criteria. Discrepancies between the reviewers were resolved by discussion and consensus, and the final results were reviewed by the senior investigator. The following data were extracted from the included articles: study design, methodology, year of data collection, sample size and characteristics, outcomes, exposure, and comparators.

  The cross-sectional studies were appraised using appropriate tools for each study design. The Newcastle-Ottawa Scale (NOS) and NOS-derived survey scale [15] were used to assess the risk of bias (ROB) in three domains, and the maximum score is 9 points: 1) selection of study groups (0 - 4 points), 2) comparability of groups (0 - 2 points), and 3) ascertainment of exposure and outcomes (0 - 3 points) for cross-sectional studies [14]. Scoring was undertaken by two reviewers, with a third reviewer resolving any disagreements. Studies were considered at low ROB when the overall scores were 9 - 10, moderate when scores were 6 - 8, and high when the scores were 0 - 5. Research questions were developed based on the NOS questions covering all three domains so that the authors could provide detailed information about their studies.

  Quantitative data were grouped based on the following relevant variables: degree of qualification, occupation area, and years of practice. Data on knowledge, practices and attitudes of healthcare professionals as well as their perception of the new way of working in the clinical setting were also categorized. With regard to the protocol studies, the main points in each study were selected, grouped according to similarity, and presented in a table. The data were analyzed and grouped by all three researchers, and the tabulation of all data was performed by one researcher. After tabulating the data, the data were reviewed by another researcher, hence decreasing the possibility of disagreements.

Results

  Figure 1 shows a flowchart illustrating the selection of studies for inclusion in the systematic review. After searching all scientific databases for related studies, a total of 87 articles were selected; after removing the unrelated and duplicate articles, 19 were assessed for eligibility. Finally, only 14 articles were included in the qualitative analysis, while 9 were included in the quantitative analysis.

Figure 1: PRISMA 2009 flow diagram.

  Nine articles fulfilled the criteria for quantitative and qualitative evaluation and were included in the final step of the systematic review. The final articles were cross-sectional studies and assessed the knowledge, attitudes and practices, as well as the perception of dentists regarding the COVID-19. These studies underwent quality assessment using NOS and obtained a score ranging from 7 to 8; this score indicated that the studies had moderate quality. The other four studies reported the clinical care protocols. These protocols were used for a brief qualitative review and as a basis for establishing a new clinical protocol.

  A detailed description of the included studies is shown in table 1. The pooled data from studies (n = 12,913) included the characteristics of dentists who completed the survey questionnaire: associations of male gender (n = 6,690; 51.8%); qualifications: postgraduate (n = 4,680; 36.2%), graduate (n = 4,214; 32.6%), auxiliary staff (n = 202; 1.56%), and interns (n = 162; 1.2%); occupational area: academic (n = 888; 6.9%), clinician (n = 10,931; 84.5%), and others (n = 486; 3.8%); years of practice (n = 6,206): 0–10 years (n = 2,997; 48.3%), > 10 years (n = 3,105; 50.0%), and currently not practicing (n = 103; 1.7%).

Table 1: Socio-demographic distribution of the respondents.

  Data regarding the dental professionals’ knowledge, attitudes, and practices, as well as perception and psychological aspects during the COVID-19 pandemic are shown in table 2.

Table 2: Knowledge, attitudes/practices and perception/psychological aspects data assessed in selected studies.

Discussion

  This study systematically reviewed several cross-sectional studies by conducting a questionnaire survey and using care protocols aimed at examining the strategies adopted by dental health professionals in providing patient care during the period of the COVID-19 pandemic. Considering the knowledge, attitude, and practices adopted by dental professionals during the COVID-19 pandemic, a protocol must be followed in order to prevent or interrupt the chain of COVID-19 transmission.

  The dental team must take precautions to reduce the spread of infection. Adequate information and training must be provided these healthcare professionals to control infections in the dental office [16,17]. In Quadri., et al. [18], a questionnaire was administered to 706 dental health professionals. Of them, 500 were knowledgeable about COVID-19, while 206 were unaware of this disease. In the group that had no knowledge about COVID-19, after the training, a significant improvement (p < 0.05) was observed in the groups’ knowledge regarding the disease.

  Dental care professionals should have sufficient knowledge regarding mode of COVID-19 transmission and other viral agents, the methods of identifying patients with active infections and measures that can protect them and their patients from acquiring COVID-19. The basic principle of infection control is to treat each patient as if they are infected and implement the correct protective strategies [19]. Previous studies have shown that even non-symptomatic patients can spread the virus [20,21].

  Previous studies have evaluated the knowledge of dentists in relation to COVID-19 [18,22-25], signs and symptoms related to the disease [18,22-24,26], transmission routes [6,18,22,23], hygienic measures [6,8,10,27] and the importance of using PPE [6,8,10,18,22-25,27,28]. Health professionals must provide clear and easy guidelines for managing patients and must maintain a safe dental practice to reduce the risk of disease transmission [29].

  Measuring the temperature of patients before dental treatment is an important step that should be adopted as a form of prevention in the care of infected patients. Some proposed methods have been adopted to measure temperature, such as less than a quarter of patients [24]. The dental assistant measures the body temperature without direct contact with the patient using infrared thermometers [6,8,26]; an initial telephone interview with the patient must be made in order to verify whether he or she had a fever or developed other signs of COVID-19 [24].

  Two studies assessed the study patients for signs and symptoms of COVID-19 [17,24]. One study reported 474 dental surgeons with COVID-19 symptoms, 31 dental surgeons who tested positive for SARS-CoV-2, 16 individuals who developed the disease [24], 314 individuals with suspected COVID-19, and 33 individuals who tested positive for SARS-CoV-2 [17]. These data were used to verify whether testing of symptomatic professionals is an essential measure to prevent the spread of the disease. The primary method to prevent disease spread is to prohibit the symptomatic professionals from seeing their patients, mainly due to the large number of false-negative cases in relation to COVID-19 [30-32].

  The spread of viral particles in the form of aerosols is considered as the primary route of COVID-19 transmission [2,33]. Dental surgeons should minimize the use of aerosol-generating procedures and the conscious implementation of this practice is recommended [6,26]. During dental procedures, inhalation of aerosols produced by instruments used in patients with COVID-19 increases the risk of disease spread. It is also possible to detect the presence of viral particles in the saliva of patients with COVID-19 [12], elective procedures should be postponed until the end of the acute phase and only urgent and emergency care should be provided [6,8,10].

  Several studies have also been evaluated the attitude changes during the period of pandemic: anamnesis reported via telephone interview [8], decrease in the number of patients [17,24], care provided only during emergency cases [16,17,22,23], increased ventilation of the rooms after an appointment and local cleaning [8] and training of clinical staff on the correct use of PPE and other safety measures [16,17] were reported in the studies analyzed.

  The use of PPE for the entire dental team is recommended, and the use of equipment that produces aerosols must be avoided [6]. If the use of these equipment is required during a dental procedure, absolute isolation must be implemented and high-power suction must be used in order to control and minimize the dispersion of contaminated aerosols. During radiographic examinations, extraoral measures must be preferred over intraoral ones, since the latter can stimulate greater salivary production, thus increasing the risk of contamination. There is currently no consensus on the correct use of solutions for mouthwash. Previous studies showed that dental surgeons are recommending various types of products without determining their effectiveness [24,25,28]. There is still insufficient scientific evidence to prove the effectiveness of a mouthwash against coronavirus, suggesting the need for further studies in this area.

  The masks are used to protect professionals and patients, limiting the potential spread of infectious respiratory aerosols. They can be used with glasses to protect the mouth, nose and eyes, or with a face shield to provide more complete facial protection. The mouth, nose, and eyes serve as portals of entry of infectious pathogens [4]. Surgical masks are used to prevent large particles (such as droplets, sprays, or splashes) from reaching the nose and mouth [34]. Although masks are used to protect patients from healthcare professionals by minimizing exposure to saliva and other respiratory secretions, they do not create a seal on the skin of the face and are therefore not indicated to protect people from infectious diseases transmitted by air.

  When treating patients with respiratory infections, particulate respirators such as N95 [4] should be worn by professionals [6,8,10,17,18,23,24]. In the study developed by Duruk., et al. [28], it was found that only 12% of professionals adhered to the use of an N95 mask. This low adherence led to an increase in the rate of contamination; hence, the dentists’ rate of adherence to this measure increased.

  Disposable face shields may also be used in addition to protective glasses and masks. The facial protector covers other areas of the face besides the eyes. The face shields extend from the chin to the forehead, thus offering better protection of the face and eyes against splashes [35].

  Cagetti., et al. demonstrated that half of the professionals included in their study used face shields. Meanwhile, Peditto., et al. suggested the adoption of glasses, protective visors and masks, even when performing procedures that do not generate aerosols [8].

  Gloves are essential in all dental procedures. In most of the studies analyzed, professionals are knowledgeable and aware about the importance of using this item as an essential form of prevention [6,17,18,24]. Moreover, it is extremely important to maintain excellent hand hygiene practices before and after performing each procedure in order to protect all members of the dental team. Recent studies [8,17,18,23,24] reported a great number of professionals who adopted this measure as an essential prevention procedure.

  Several studies have proposed a protocol to reduce the biological risk (Table 3). The studies analyzed provided an overview of the professionals’ level of understanding about the new ways of working in the clinical setting. Hence, a new dental care protocol was developed based on scientific evidence and practices already adopted by most dental professionals, with a focus on the procedures that are not yet massively implemented. The actions of dentists need to be reorganized in the following situations: before appointment (Figure 2), handling of the operative area (Figure 2), and use of PPE (Figure 3 and 4).

Table 3: Protocols assessed in protocol studies selected.

Figure 2: Flow diagram of Before appointment and Protective area measures.

Figure 3: All steps to clothe the personal protective equipment (adapted from Sales-Peres, 2021 [36]).

Figure 4: All steps to remove the personal protective equipment (adapted from Sales-Peres, 2021 [36]).

Before appointment

Before dental care, it is essential to take preventive and diagnostic measures to optimize care:

1. Telephone triage: This method will assess the need for and urgency of dental treatment. Treatments that are not considered necessary at the moment should be reconsidered.
2. Decrease elective appointments: Teleconsultation can be performed in order to make a diagnosis and decrease the face-to-face contact in a dental office. If there is a need for face-to-face assistance and procedures, these must be carried out with due care for biosafety. If elective procedures can be postponed, this action must be carried out.
3. Short interview about symptomatology: To better diagnose possible cases of patients infected with the new coronavirus, an anamnesis on signs and symptoms associated with the disease is recommended. The dentist surgeon, as a health professional, must guide the possibly infected patient and may even postpone their care if it is not an emergency treatment. In this case, a drug must be prescribed if needed.
4. Spacing appointment schedule: To avoid the flow of many patients in the waiting room and to ensure that the necessary hygiene measures can be carried out, the schedule of appointments between patients must have a longer interval. This longer time between dental care procedures should be sufficient for all disinfection measures to be carried out in the operative area as well as the changes in the protectors used and ventilation of the room.

Operative area: The patient's temperature should be measured before entering the room. In the operating environment, protectors should be used in the dental chair, instrument bench, and turbines. This protection must be changed after each patient's care. All surfaces must be disinfected - soaking the surfaces with a bleach containing 5.25% - 8.25% sodium hypochlorite for at least 1 min or spraying them with 70% alcohol [36] - after contact with each patient. High-power suction and absolute insulation with a rubber sheet should be used whenever the procedure allows. The ventilation of the operating room must be performed after each appointment.

PPE use: Complete PPE must be used for all procedures:

1. N95 mask + surgical mask: The use of a surgical mask in addition to the N95 mask allows the N95 mask to have a longer use time (maximum 15 days).
2. Goggles + face shield: The use of a face shield protects the face from the generated aerosols; however, the protective glasses cause a more effective eye sealing effect.
3. Gloves: For all dental procedures, disposable gloves should be used.
4. Shoe cover: The shoe cover must be used to avoid spreading the virus outside the office. Alternatively, plastic shoes can be used as they are easy and quick to disinfect.
5. Disposable caps: The disposable caps should be used to avoid contamination with aerosols dispersed in the environment.
6. Disposable protective clothing: They must be worn over the professionals' clothing and must be changed after each patient is treated. These aprons should cover as much of the exposed area as possible. It is b that surgical pajamas can be worn under disposable clothing. These pajamas should only be used in an operating environment to avoid spreading microorganisms to other external environments.