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Year : 2020  |  Volume : 4  |  Issue : 5  |  Page : 56-59

Coronavirus: A potential threat for dental practitioners

1 Department of OMFS, MVJ Medical College and Research Hospital, Bengaluru, Karnataka, India
2 Department of Periodontics, Hi Tech Dental College and Hospital, Bhubaneswar, Odisha, India
3 Department of Pedodontics and Preventive Dentistry, Awadh Dental College and Hospital, Jamshedpur, Jharkhand, India
4 Department of Oral and Maxillofacial Surgery, Awadh Dental College and Hospital, Jamshedpur, Jharkhand, India
5 Department of Oral Medicine and Radiology, Government Dental College, Kottayam, Kerala, India

Date of Submission23-Apr-2020
Date of Acceptance02-May-2020
Date of Web Publication13-Aug-2020

Correspondence Address:
Dr. Bhupender Singh Negi
Department of Oral Medicine and Radiology, Government Dental College, Kottayam, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/bbrj.bbrj_61_20

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Coronaviruses are large, enveloped RNA viruses composed of few structural proteins and mainly infect birds and mammals including humans. The first case of coronavirus was described in China in December 2019. Novel coronavirus (SARS-CoV-2) infects the human respiratory, nervous, enteric, and hepatic systems. Individuals with a potential SARS-CoV-2 exposure present with the mild symptoms of low-grade fever, dry cough, shortness of breath, nasal congestion, and headache and muscle pain. In the later stages, these symptoms worsen leading to severe pneumonia, acute respiratory distress syndrome, sepsis, and multiple organ failure. These days this pandemic is emerging as a major threat for the health-care professionals including dental surgeons. The dental surgeons are at greater risk of novel coronavirus infections due to direct contact with infected patients and exposure to contaminated blood, saliva, and other body fluids. This article deals with viral structure, methods of detection, and modes of transmission, especially in dental settings.

Keywords: Dental, pandemic, SARS-CoV-2

How to cite this article:
Shilpa R H, Pattnaik SJ, Pani P, Pani N, Negi BS. Coronavirus: A potential threat for dental practitioners. Biomed Biotechnol Res J 2020;4, Suppl S1:56-9

How to cite this URL:
Shilpa R H, Pattnaik SJ, Pani P, Pani N, Negi BS. Coronavirus: A potential threat for dental practitioners. Biomed Biotechnol Res J [serial online] 2020 [cited 2022 Aug 14];4, Suppl S1:56-9. Available from: https://www.bmbtrj.org/text.asp?2020/4/5/56/292087

  Introduction Top

Novel coronavirus (SARS-CoV-2) was first reported from Wuhan, China, from where it has spread to most other provinces including other 24 countries. The World Health Organization declared this as pandemic and an emergency situation of international concern over this global pneumonia outbreak on January 2020.[1] The SARS-CoV-2 strain has genetic correlation with SARS-CoV that resulted in a global epidemic affecting more than 25 nations with total deaths at 8096 cases.[2],[3],[4]

The typical clinical symptoms of the patients who suffered from the novel corona infection include fever, cough, and myalgia or fatigue with abnormal chest computed tomography, and the less common symptoms were sputum production, headache, hemoptysis, and diarrhea.[5] This new infectious agent is more likely to affect older adults and children to cause severe respiratory diseases.

The asymptomatic incubation period of the virus is estimated to be between 2 and 12 days. The most common symptoms of coronavirus disease include fever, tiredness, dry cough, and shortness of breath. More than 80% of cases are mild and recover from the disease without needing special treatment. However, around 15% of cases are categorized as severely ill, and the remaining 5% are categorized as critically ill. In severe and critical cases, acute respiratory disease can lead to pneumonia, kidney failure, and even death.[6]

The treatment of SARS-CoV-2 is mainly supportive and based on the symptoms. Hence, adequate isolation for the prevention of transmission is important. Mild symptoms can be managed at homes with the maintenance of adequate hydration, appropriate nutrition, and control of fever and cough. The use of antibiotic and antiviral agents must be avoided in positive participants. Hypoxic participants are supported with oxygen supply using high-flow nasal cannula or noninvasive ventilation. Renal replacement therapy may be required. Current international consensus along with WHO advises against using antimicrobials.[7]

The symptoms of illness from SARS-CoV-2 transmission begin only days after its transmission and has moderate amount of viral load within respiratory tract fluid/secretions very early in the disease with peak load approximately 10 days following symptoms' development.[4]

Dentists are routinely exposed to pathogenic microbial organisms infecting oral cavity and respiratory tract. Thus, there is a risk of 2019-nCoV infection due to dental procedures which involve direct communication with and exposure to various bodily fluids and various contaminated surfaces.[8]

  Mechanism of Sars-Cov-2 Transmission Top

The common transmission routes of novel coronavirus include direct transmission through coughing, sneezing, and through droplet inhalation and contact transmission through touching oral cavity, nasal cavity, and eyes. SARS-CoV-2 can also be transmitted directly or indirectly through saliva.

SARS-CoV-2 expresses the typical structural protein: The “spike protein” in the membrane envelope and also possess other polyproteins, nucleoproteins, and membrane proteins, such as RNA polymerase, 3-chymotrypsin-like protease, papain-like protease, helicase, glycoprotein, and accessory proteins.[9],[10]

Coronavirus gains entry into the target cell through the S protein that binds to the receptors of the host. Although there are four amino acid variations of S protein between SARS-CoV-2 and SARS-CoV, SARS-CoV-2 can bind to the human angiotensin-converting enzyme 2 (ACE2), receptor from the cells from human, bat, cat, and pig, but it cannot bind to the cells without ACE2. SARS-CoV-2 and SARS-CoV have same host cell entry pathway that is through ACE2 cell receptor. SARS-CoV-2 also promotes human-to-human transmission through ACE2+ cells. ACE2+ cells are located in the human body:[10],[11]

  1. In the epithelium of the respiratory tract
  2. In the ductal epithelium of salivary glands in human mouth.

Dental patients and professionals can be exposed to pathogenic microorganisms, including viruses and bacteria that infect the oral cavity and respiratory tract. Dental care settings invariably carry the risk of SARS-CoV-2 infection due to the specificity of its procedures, which involves face-to-face communication with patients, and frequent exposure to saliva, blood, and other body fluids, and the handling of sharp instruments. The pathogenic microorganisms can be transmitted in dental settings through the inhalation of airborne microorganisms that can remain suspended in the air for long periods, direct contact with blood, oral fluids, or other patient materials, contact of conjunctival, nasal, or oral mucosa with droplets and aerosols containing microorganisms generated from an infected individual and propelled a short distance by coughing and talking without a mask, and indirect contact with contaminated instruments and/or environmental surfaces.[10],[12],[13]

  Modes of Transmission in Dental Operatories Top

Spread through airborne route

The airborne transmission of NCOVID19 through droplets and aerosol generation is of major concern for dental practitioners. All the dental equipment especially rotary hand pieces operating at a very high speed along with running water generates aerosol droplets admixed with patient's saliva and blood.[14] Small particles of droplets and aerosols remain air-borne for a large period of time before settling over any surface or entering respiratory tract. Hence, 2019-nCoV can have a potential of spreading from infected patients in dental operatories.[10]

Transmission via contaminated surfaces

NCOVID19 can persist on the contaminated surfaces of dental instruments and the equipment placed in the dental settings such as metal, glassware, and plastic surfaces for many hours. Dental professionals and even hospital staff come in contact with these contaminated surfaces frequently and thus become the source of coronavirus spread.[15]

Transmission through transplant

Fecal microbiota transplantation is a new treatment method which has rapidly earned major role in the management of recurrent Clostridioides difficile infection due to its clear advantages over antibiotics use. The risk SARS-CoV-2 transmission by means of fecal microbiota transplantation might be greater than other tissue transplants. There is evidence that SARS-CoV-2 can be traced in fecal samples. Stool samples can remain positive for the virus long after it is undetectable in respiratory tract, suggesting that there is a possibility of fecal–oral transmission route. This hypothesis can be supported by gastrointestinal symptoms subjects who are affected by COVID-19.[7]

  Recommended Protective Measures in Dental Settings Top

During the dental procedures, the uses of a high-speed handpiece or ultrasonic instruments generate aerosols that get mixed with patient's saliva and blood. Dental apparatus gets contaminated with various pathogenic microorganisms after use or become exposed to a contaminated clinic environment. Thus, various dental procedures can lead to the spread of COVID-19 infection. The various effective infective control measures that can be followed include:

If the patient is suspected of any sign and symptoms of coronavirus infection the dental treatment must be postponed

Only the emergency dental treatment can be delivered in an environment with proper air exchange using personal protective equipment, including masks, gloves, gowns, and goggles or face shields, as respiratory droplets are the main route of SARS-CoV-2 transmission, particulate respirators (e.g., N-95 masks authenticated by the National Institute for Occupational Safety and Health or FFP2-standard masks set by the European Union) are recommended for routine dental practice[16]

Hand hygiene has been considered the most critical measure for reducing the risk of transmitting microorganism to patients. Wash your hands frequently with soap and water counting up to 20 (approx. 20 s)[17]

Eye protection and contact preventative measure should be added in the dental clinic setups

The four-handed technique is beneficial for controlling infection in dental clinics. The use of saliva ejectors with low or high volume can reduce the production of droplets and aerosols.

Apart from dental practice, few basic recommendations for dental educational institutes during this outbreak are necessary: Dental students should be encouraged to make use of smart devices and applications to attend online lectures, case presentations, and problem-based learning tutorials thus avoiding unnecessary aggregation of people and associated risk of infection.[18]

Dental education institutes must encourage the students to engage in self-learning, make full use of online resources, and learn about the latest academic developments.[16]

  Dental Treatment Protocols Top

Patient screening

During the outbreak of COVID-19, dental clinics are recommended to establish precheck triages to measure and record the temperature of every staff and patient as a routine procedure. Dental clinic staff should evaluate the patients on basis of the health status and history of contact or recent travel. Before the dental treatment procedures, patients and their accompanying persons must be examined for body temperature. Patients with fever should be registered and referred to medical hospitals. Any patient with a history of recent travel to an epidemic region should be isolated for at least 14 days before any dental procedure.

Examination of oral cavity and preprocedural mouth rinse

Before examining the oral cavity, the patient should be asked to rinse with antimicrobial mouth rinse to reduce the microbial load in the oral cavity.[19] It is recommended to use mouthwash-containing oxidative agents such as 1% hydrogen peroxide or 0.2% povidone, for the purpose of reducing the salivary load of oral microbes.[10]

All the dental procedures that generate aerosols in excess and induce salivation and coughing should be avoided or performed cautiously.[20] The use of a 3-way syringe should be minimized as much as possible. The examination of the oral cavity using intraoral radiographs should be minimized to reduce the risk of salivary stimulation and cough. Thus, the use of alternative radiographic methods such as orthopantomography (OPG) and Dentascan must be encouraged during pandemic outbreak.

Emergency dental procedures

Dental emergency procedures should be performed under caution by using face shields and goggles. The use of rubber dam isolation and anti-retraction hand pieces should be encouraged. Rubber dam along with high-power suction reduces the risk of saliva and blood contaminated aerosol or spatter production. It has been reported that the use of rubber dam significantly reduces the airborne particles in ~ 3-foot diameter of the operational field by 70%.[21]

It is necessary to use hand pieces with anti-retraction valves as the microorganisms like bacteria and viruses may contaminate the air and water tubes within the dental unit, and thus can potentially cause cross-infection. Thus, these anti-retraction valves prevent the backflow of oral microbes into tubes and dental unit, thereby minimizing the risk of cross infection.[10],[22]

Whenever pharmacologic management of pain is required, ibuprofen should be avoided in suspected and confirmed COVID-19 cases.[6]

Biomedical waste disposal

It is necessary to dispose the medical waste from dental operatories with proper care.

The medical and domestic waste generated by the treatment of patients with suspected or confirmed SARS-CoV-2 infection is regarded as infectious medical waste. The infected waste should be pretreated first with chemicals then disposed. Biomedical waste management should be appropriately done using double-layer yellow color waste package bags and proper ligation of these at necks.[10] The surface of the package bags should be marked and disposed according to the requirement for the management of medical waste.

  Methods of Testing and Diagnosis Top

The primary mode of transmission of SARS-CoV-2 is through the respiratory route. At present, the diagnosis of COVID-19 is mostly being accomplished by performing real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) for SARS-CoV-2 on respiratory specimens such as nasopharyngeal swabs.[23],[24] This test amplifies viral RNA in a patient's specimen for the detection of SARSCoV-2 genetic material. False negatives are possible due to multiple variables including simple technical errors, inadequate collection, improper handling, and shipping. Other possibilities for incorrect results include flawed key reagents in the kit.[17]

As the COVID-19 outbreak has a rapid spread, its National Transplant Center has taken strong steps and has recommended testing of all potential tissue as well as stem cell living along with donors who are dead using the real-time RT-PCR assays of nasopharyngeal swab samples or of bronchoalveolar lavage obtained from deceased subjects.[25]

However, histopathological findings show infiltration of a few neutrophils and monocytes. There are also increased numbers of intraluminal alveolar macrophages in macaques after intratracheal inoculation with SARSCoV-2. RNA is present predominantly in type II alveolar epithelial cells, with less in type I epithelial cells.[26]

Laboratory features

Laboratory findings specific to SARSCoV-2 include:

Elevated prothrombin time, lactate dehydrogenase, D-dimer, alanine aminotransferase (ALT), C-reactive protein (CRP), and creatine kinase. Levels of CRP correlate directly with disease severity and progression[27]

In the early stages of the disease, a marked reduction in CD4 and CD8 lymphocytes can also be noted

Sever symptomatic cases show higher levels of interleukin (IL) 2, IL-7, IL-10, granulocyte colony-stimulating factor, interferon gamma-induced protein 10, monocyte chemotactic protein 1, macrophage inflammatory protein alpha, and tumor necrosis factor-α[28]

In critical patients, amylase and D-dimer levels are significantly elevated.[29]

  Conclusion Top

Most important step in COVID-19 management is identifying a suspected subject. Such a subject must not be treated in dental settings and should be immediately referred to health services for quarantine and other effective measures. The use of personal protective measures such as gloves, eyewear, or face shield should be done. The use of anti-retraction hand pieces can also reduce aerosol spread to a large extent.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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