ANVISA-TECHNICAL NOTE GVIMS/GGTES/ANVISA NO. 04/2020

This document summarizes not only what science has shown so far about COVID-19 within dentistry, but also what regulatory agencies and other health services have made available to our class about the contamination risks we are subject to when treating our patients. We also address the protocols that, if properly followed, can be effective in controlling infection in the dental environment.

History of the Pandemic

On January 8, 2020, a new coronavirus was officially announced as the pathogen causing COVID-19 by the Chinese Center for Disease Control and Prevention (Li et al., 2020). COVID stands for Corona Virus Disease, while "19" refers to 2019, when the first cases in Wuhan, China, were made public (Oswaldo Cruz Foundation, 2020).

The epidemic (COVID-19) began in Wuhan, China, in December 2019 and has become a major public health problem, challenging not only China but also almost every country in the world (Phelan et al., 2020). On January 30, 2020, the World Health Organization (WHO) announced that this outbreak would constitute a global public health emergency (Mahase, 2020).

The majority of patients affected by COVID-19 are considered mild cases, but cases can worsen to severe pneumonia and death. The most common symptoms are fever and dry cough, but patients may also experience shortness of breath, fatigue and other atypical symptoms such as muscle pain, mental confusion, headache, sore throat, diarrhea, vomiting and a change in smell. The disease can also have serious complications, such as acute respiratory distress syndrome, arrhythmia and shock, requiring care in intensive care units.

In general, advanced age and the existence of underlying morbidities such as diabetes, hypertension and cardiovascular disease are associated with an unfavorable prognosis (Liu et al., 2020; Wang et al., 2020; Yang et al., 2020).

In France, the first documented report was of a 48-year-old male patient who was traveling for professional reasons in several cities in China, including Wuhan, and had his first symptoms on January 16, 2020. After flying back to Bordeaux, France, on January 22 he sought medical attention and was diagnosed with COVID-19 on January 24, 2020 by the National Reference Center (Stoecklin et al., 2020).

In the United States on January 19 of this year, a 35-year-old man presented himself to an emergency clinic in Snohomish County, Washington, with a four-day history of cough and subjective fever. He revealed that he had returned to Washington state on January 15, after traveling to visit family in Wuhan, China. Given the patient's travel history, the local and state health departments were immediately notified. Serum samples and nasopharyngeal and oropharyngeal swabs were collected and on January 20, the U.S. Centers for Disease Control and Prevention (CDC) confirmed the results for COVID-19 (Holshue et al., 2020).

In Brazil, on February 26, the Ministry of Health confirmed the first case of COVID-19 in Latin America, in a 61-year-old male patient diagnosed in the city of São Paulo. The patient was admitted to Hospital Israelita Albert Einstein on Tuesday, February 25, with a history of travel to Italy, Lombardy region (Candido et al., 2020; Rodriguez-Morales et al., 2020). The self-reported travel history and subsequent analysis of viral genetic variability confirmed that this infection had been acquired through importation of the virus from northern Italy (Candido et al., 2020).

Faced with a growing global epidemic, the WHO declared on March 11 that COVID-19 is a pandemic disease. The decision was announced by the head of the agency, Tedros Ghebreyesus, in Geneva with the following information "The disease, which emerged at the end of December in China, is now present in 114 countries and in the last two weeks, the number of new daily cases outside China has increased 13-fold. And the number of countries affected has tripled".

Due to the history of the disease and the characteristics of dental care in both the public and private sectors, the risk of cross-infection can be high between dentists and patients. For dental practices and hospitals in countries/regions potentially affected by COVID-19, strict, urgent and effective infection control protocols are needed (Meng et al., 2020).  

Incubation period

The incubation period for COVID-19 has been estimated at an average of 5 to 6 days, but there is evidence that this period can last up to 14 days, which has become the commonly adopted duration for medical observation and quarantine of potentially exposed people (Backer et al., 2020; Li et al., 2020). 

The Ministry of Health defines quarantine as: isolation of healthy individuals or animals for the maximum incubation period of the disease, i.e. the time between contact with the causative agent and the manifestation of symptoms of the disease. Also according to the Ministry of Health, the quarantine period starts from the date of the individual's last contact with a clinical case or carrier, or from the date that this healthy communicant left a place where there was a source of infection.

Effective protocols for infection control in the dental environment

Hand hygiene has long been considered the most critical measure to reduce the risk of transmitting microorganisms to patients (Larson et al., 2000). However, when it comes to SARS-CoV-2, this virus can persist on surfaces for a few hours or even several days, depending on the type of surface, the temperature and/or the humidity of the environment (WHO/WHO 2020c). 

This reinforces the need for good hand hygiene and the importance of thorough disinfection of all surfaces in the dental clinic. The use of personal protective equipment (PPE) is recommended, including masks, gloves, aprons, goggles and face shields, to protect skin and mucous membranes from (potentially) infected blood or secretion. As respiratory droplets are the main route of viral transmission, particulate respirators (e.g. N-95 masks authenticated by the National Institute for Occupational Safety and Health or standard FFP2 masks defined by the European Union) are recommended for routine dental procedures.

Based on WHO experience and guidelines defined by scientific research, dentists should adopt strict personal protection measures and avoid or minimize procedures that could produce droplets or aerosols. The four-handed technique is beneficial for controlling infection. The use of saliva suckers can reduce the production of droplets and aerosols (Kohn et al., 2003; Li et al., 2004; Samaranayake and Peiris, 2004).

Figure 1. Recommendations for dental surgeons to prevent COVID-19.

Dental examination

Procedures that are likely to induce coughing should be avoided (if possible) or performed with caution (WHO/WHO 2020a). Aerosol-generating procedures, such as the use of a 3-way syringe, should be minimized as much as possible. 

Intraoral radiological examination is the most common radiographic technique for dental imaging; however, it can stimulate secretion and coughing (Vandenberghe et al., 2010). Therefore, extra-oral dental radiographs, such as panoramic radiography and cone beam computed tomography, are appropriate alternatives during the COVID-19 outbreak.

Dental treatment in emergencies

Dental emergencies can arise and worsen in a short period of time and therefore need immediate treatment.

 Rubber dam insulation and high-powered saliva suckers can help minimize aerosol or splashes in dental procedures. In addition, face shields and goggles are essential with the use of high or low speed handpieces with water spray (Samaranayake et al., 1989).

 If a decayed tooth is diagnosed with symptomatic irreversible pulpitis, access to the pulp can be achieved by chemicomechanical removal of the caries, under absolute isolation with a rubber dam and a high-powered saliva sucker after local anaesthesia; the pulp is then devitalized and a delayed dressing is placed with the drug of choice, with the aim of reducing painful sensitivity. At a later stage, conventional treatment can be completed following conventional therapeutic protocols.

Another practice to be adopted is the rationalization of patient scheduling, seeking spacing between appointments in order to correctly carry out cleaning and disinfection procedures and consequently reduce the risk of cross-contamination.

Position of the American Dental Association

The American Dental Association (ADA), through its interlocutors Mia Geisinger, Marcelo Araujo and Dave Preble, has recommended the use of surgical masks and, if available, N-95 respirators, for all procedures. The recommendations also suggest that surgical masks should be discarded after each use.

Also according to the ADA, it should be borne in mind that during the clinical procedure a safe distance needs to be respected between the patient and the dentist/dental team because the CDC and other government agencies state that "Thefact that professionals stand too close to patients at the time of care can cause transmission because the act of speaking or breathing produces aerosol". Therefore, the recommendation is that care should take place in an environment with a low risk of contamination.  

In addition to the N-95 respirators, the USFood and Drug Administration(FDA) has announced the emergency authorization of the use of KN-95 respirators, produced in China. These are similar to the N-95 in terms of particle filtration. In both situations, it is important for users to carry out a seal test and adaptations after putting on the respirators in order to make them as tight as possible. Looking at the two devices, N-95 and KN-95, they are very similar, the main difference being an additional layer of air filtration in the N-95 respirator, due to the device on the front. So far, based on the data provided by science, no major differences have been found between KN-95 and N-95, and both are within the required standard.

The ADA, like the FDA, is working to ensure that the recommendations given are based on scientific evidence, and has drawn up regulations highlighting the fact that dental professionals (including all team members) can help to reduce the spread of the virus (Q&A: COVID-19 Transmission and Emergency Care, 2020).

It is known that the use of mouthwashes has an antimicrobial action in the preoperative period and can reduce the number of viable bacteria in the oral cavity (Kohn et al., 2003; Marui et al., 2019). However, there are still no clinical studies supporting the antiviral effect of mouthwashes as a preventive method for pre-care contamination in relation to COVID-19. According to Marcelo Araujo, ADA Chief Science Officer , "The use of mouthwash can reduce the risk of contamination immediately after rinsing, but it does not guarantee a solution to the problems in terms of prevention during the entire procedure because the viral particles come from the lung and, if the patient breathes or coughs after rinsing the mouth, the field will be exposed again, and recontaminated with the particles coming from the lung through the respiratory tract" (Q&A: COVID-19 Transmission and Emergency Care, 2020).

Position of the Federal Council of Dentistry

The Federal Council of Dentistry (CFO) recommends caution and care in the activities carried out by oral health professionals working throughout the country due to the WHO's declaration that COVID-19, a disease caused by the new coronavirus, is a pandemic.

"We would like to point out that the incubation period for COVID-19, i.e. the time between the day of contact with the source of transmission and the onset of symptoms, has been recorded at between 5 and 14 days. It is therefore important that this time window is respected in the event of confirmation of infection."

The CFO emphasizes: "Dental professionals are urged to take extra care and use personal protective equipment effectively to avoid exposure and infection by the new coronavirus (COVID-19). Screening should also be carried out before dental appointments to check for possible symptoms of COVID-19. If symptoms are detected, professionals should refer patients for medical attention with the description they have observed. The time is ripe for joint actions between civil society, public agents, researchers and health professionals to tackle this new epidemic quickly, reducing the damage to the population's health and the social and economic consequences in our country."

Sobrape's position

While the WHO defines guidelines for all health professionals, from nutritionists to doctors and physiotherapists, the ADA and CFO regulations are aimed exclusively at dentists, regardless of their specialty.

In comparison, SOBRAPE - which focuses on clinical practice, teaching and research in periodontics - has a very specific field of activity. However, professionals linked to Sobrape are at high risk of contamination when practicing their profession. In this way, the actions of specific associations can contribute both positively and negatively to the overall results. In this context of making a positive contribution, Sobrape has kept in line with the applicable international standards published by regulatory bodies.  

In fulfilling its duties and social role, Sobrape has contributed to containing the spread of COVID-19 and to the health of periodontists, patients and, consequently, the general population. As a specific action, it has published a manual called GUIA ODONTOLÓGICO PARA ATENDIMENTO DURADO A PANDEMIA COVID-19 (ODONTOLOGICAL GUIDE FOR ATTENDANCE DURING THE COVID-19 PANDEMIC ) and has been promoting various lives encouraging people to stay at home and providing safer clinical care.

 In addition to encouraging social isolation, Sobrape has participated in campaigns with partner institutions such as the Ibero-American Federation of Periodontics and the Spanish Society of Periodontics and Osseointegration. Sobrape has also continued its continuing education activities remotely, keeping professionals up to date.

Final considerations

There has been extensive mobilization by all sectors of activity to minimize the effects of the pandemic around the world. The WHO, for example, says it is working on the development of a vaccine against COVID-19, and researchers are using scientific evidence from well-designed clinical studies to find which therapy or therapies could be effective in combating the viral infection. Trade organizations are keen to inform their peers how to prevent the spread of the disease and, consequently, minimize its damage. Everyone, in some way, has been touched by the current situation and is trying, with a lot of thought, to come up with something positive.

What we do know for sure about this pandemic is that everything seems new and science still has a long way to go, as different situations of both contagion and patient recovery do not follow a uniform or predefined pattern. For example, the WHO and the Korean Center for Disease Control and Prevention (KCDC) are investigating why some patients who had already recovered from COVID-19, with negative test results, later re-tested positive. A similar situation of positive tests in recovered patients has also been recorded in China. So the question remains "Could a contaminated and recovered patient have a new viral infection and consequently become a transmitter again? 

According to the vice director of the KCDC, Kwon Joon-wook, it seems that there is still no evidence that a person who has tested positive isatransmitter, but he adds: "This is still an unanswered question, as it has not been confirmed in studies, although researchers are cultivating the virus and checking whether this potential exists."

   This text, recognizing its limitations, was written with the aim of contributing to knowledge about COVID-19, especially in relation to the care that we health professionals must take with our patients and, above all, with ourselves.

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