Dental Practice Implications of COVID-19: An Update

Resultantly, from March 16 to April 30, 2020, the American Dental Association called for postponement of all but emergency and urgent dental procedures.² This was advised in an attempt to both lower COVID-19 transmission rates and preserve the limited supply of personal protective equipment (PPE). By the end of May 2020, most US state governments lifted these restrictions, permitting dental practices to resume providing care while following stringent guidance from state and local health departments, the Centers for Disease Control and Prevention (CDC), and the Occupational Safety and Health Administration (OSHA).²

Guidance from these federal and state agencies included recommendations for patient and provider screening protocols, infection control, and airflow changes. As a result of these policies and procedures, dental offices proved not to be major sources of COVID-19 transmission. In fact, data indicates that COVID-19 infection rates among dentists remain lower than other health professionals, including physicians and nurses.³ This reduced rate of COVID-19 infection among dentists indicates that the mitigation measures recommended for dental offices likely provide an effective means to reduce transmission.

That said, an evolving virus and a world desperate to shed COVID-19-related restrictions warrant consideration of the efficacy of recommended measures in protecting patients and providers alike. As clinicians and scientists came to better understand the virus, recommended protection measures changed to reflect the evolving science. For example, COVID-19 is now understood to spread from person to person via respiratory droplets, rather than via contaminated surfaces.⁴ As a result, evidence-based practices to protect providers and patients in a dental setting have evolved from the time the pandemic was first declared. These measures will likely continue to evolve as further data is evaluated.

Although surges of infections continue to occur, most recently driven by the Delta variant,⁵ and the disease is likely to become seasonally endemic, providers should not feel helpless or anxious. More than a year of research has aided the scientific community's understanding of the virus, its management, and effective mitigation strategies. In essence, COVID-19 has created a paradigm shift in dentistry. The following is a summary of the state of evidence-based approaches to COVID-19 mitigation in clinical dental settings to date.

Gleaning information from numerous public health organizations, COVID-19 mitigation in the dental office involves a twofold approach to protect patients, providers, and auxiliary staff (Table 1). The first strategy simply is to keep COVID positive persons out of the office, thus minimizing the potential for exposure to the virus in the dental office. The second aims to reduce any viral transmission from asymptomatic patients. These strategies are reviewed in detail below.

1. Keeping COVID Positive Persons Out of the Dental Office

Most dental settings are not properly equipped to treat patients with COVID-19. To do so requires true negative pressure systems along with the highest level of PPE. Therefore, on both a personnel and patient level, COVID-19 mitigation efforts first and foremost aim to exclude potentially contagious patients from the office. The tools available to keep infected persons from dental settings include screening, the use of telehealth visits for assessment, and vaccination.

Screening

The primary means to keep patients, providers, and auxiliary personnel with active COVID-19 infections out of the dental office is by screening for symptoms. Those that are ill should stay home to avoid spreading illness to other patients and providers. When high levels of community transmission are present, consideration to limit extra personnel in the office should be made, allowing able personnel to work remotely and limiting guests accompanying patients.

Screening is often accomplished via screening questions and by body temperature assessment. Recommended common symptoms to incorporate into screening include fever, new cough, and difficulty breathing. However, further symptoms such as sore throat, muscle or body aches, vomiting or diarrhea, and new loss of taste or smell may be additionally included.⁶ In screening for fever, the utility of taking temperatures on patients may be twofold as many dental infections may be accompanied by a fever.

Symptomatic patients are thought to shed the highest levels of virus with direct effects on transmissibility. Therefore, screening office personnel, patients, and any other visitors to the office for symptoms should be standard practice.⁷ From a regulatory perspective, COVID-19 screening protocols, among other stipulations, are required for all non-employees, including delivery personnel, to avoid being subject to higher-level OSHA standards based on current emergency regulations.^6,8

The office environment should also encourage ill personnel to stay home. Common-sense policies aimed to minimize presenteeism, that is, the propensity to show up for work with illness, should be instituted to ensure that staff feel empowered to care for themselves when sick. This should include paid sick leave, redundancy among staff, and a culture that values wellness.

Telehealth

In cases where patients are experiencing symptoms of COVID-19, have a recent high-risk exposure, or are simply not comfortable coming into the dental office due to their own perceived risks, the use of telehealth can be considered. Electronic communication via phone or video conferencing remains a useful means for communication and care.^7,9 Patients of record can be given advice and prescribed medications using this medium. Furthermore, rudimentary examinations can lead to thoughtful discussions and planning about potential etiologies for their symptoms, as well as possible treatment options. Naturally, not being able to physically examine a patient, perform a radiographic examination, or deliver operative care presents obvious limitations. That said, in those situations where a patient cannot be seen safely in the office, care does not need to be entirely delayed.

Vaccination

FDA-approved COVID vaccines, particularly the mRNA vaccines produced by Pfizer and Moderna, are extremely effective at reducing COVID infections, especially those of the severe variety, even among new variants,¹⁰ and remain the most potent means of mitigating viral infections and, therefore, community transmission. Although the ethics of mandating vaccination among patients is questionable,¹¹ vaccine mandates among healthcare personnel is a common practice.¹² That said, evolving understanding of waning vaccine immunity and greater transmissibility of novel virus variants warrant consideration.¹³

2. Minimizing Transmission From Asymptomatic Cases

While the previously discussed mitigation strategies reflect efforts to keep persons with confirmed or suspected COVID-19 out of the dental office, the existence of asymptomatic or pre-symptomatic infections warrants the implementation of tactics to minimize transmission from these asymptomatic persons to other personnel or patients.⁷ These approaches include physical distancing, the use of PPE, procedural changes, and dental office airflow considerations.

Physical Distancing

The current best evidence indicates that COVID-19 transmission occurs mainly via respiratory particles from an infected individual. These particles spread most broadly when patients cough or sneeze, and the longest distance that many of these droplets travel is 6 feet. Consequently, 6 feet of berth around an individual is considered a relatively safe distance to assume minimal particulate transmission from person to person.⁷ Efforts should therefore be made to keep patients separated by this distance in waiting areas, hallways, and especially in treatment areas where face coverings may be removed. The need for physical distancing between providers and patients is obviated by the use of high-level PPE on the part of the provider.

Similarly, efforts should be made to keep office personnel appropriately distanced, especially when masks are removed for eating or drinking.⁷ Empirically, transmission of COVID in a dental setting may occur among staff when universal masking and distancing is not maintained. Staggered breaks among staff and adequate spacing (or dining outdoors) are simple and effective preventive measures for viral transmission.

Personal Protective Equipment

Universal masking represents a standard precaution to minimize COVID-19 transmission from symptomatic and asymptomatic individuals and is recommended for patients and providers, as well as nonclinical staff and visitors to the office. Universal masking is advised in clinical settings regardless of vaccination status, given transmission of the Delta variant even among vaccinated persons. During procedures, providers should minimally utilize level-3 masks, although a fit-tested N95 respirator or equivalent minimizes infection risk, particularly when infection rates are high in a particular community.^9,14 As supply chains become more open, many providers likely will elect to maintain the use of N95 masks for aerosol- and non-aerosol-generating procedures and even examinations.

Because COVID-19 transmission is via droplets that contact mucous membranes, and the eyes represent one such membrane, eye protection is similarly indicated universally for all providers treating patients without face coverings present.⁷ Eye protection may take the form of safety glasses or goggles or a face shield that covers the front and sides of the face. Much of the common PPE now germane among healthcare providers represents the historic OSHA standard for aerosol-generating procedures, including surgical gowns and caps, masks, and protective eyewear.⁹ All PPE should be disposable or cleaned/laundered on site (or via a service) rather than transported out of a clinical setting.

Procedural Considerations

Mouthrinses-Disinfectant mouthrinses, helpful in limiting oral flora related to periodontal or restorative procedures,¹⁵ may offer additional benefits in reducing potential viral loads in a patient with asymptomatic COVID-19 infection. Having antiseptic properties, research indicates that these rinses reduce the level of bio-aerosols produced during procedural dentistry that follows.¹⁶ Given their potential utility beyond COVID-19 mitigation, there seems to be little downside to adding these often inexpensive and efficient agents to routine dental practice. Evidence thus far is limited on the superiority of any particular rinse against coronaviruses. That said, chlorhexidine gluconate, hydrogen peroxide, cetylpyridinium chloride, and iodopovidone, among others, represent typical choices.¹⁷

Dental dam isolation-Beyond its myriad benefits to maintain a safe and clean operative field and directly increase the success rate of endodontic procedures in particular, dental dam isolation can additionally reduce the release of respiratory droplets from a patient.¹⁸ The dental dam effectively limits the production of bio-aerosols to those originating from only the isolated tooth, thus directly reducing the likelihood of respiratory particles within.¹⁶ Applying a disinfectant rinse following dental dam isolation further reduces the chance of viral particles remaining in any procedure-related bio-aerosols. Therefore, dental dam usage is considered a direct means of hazard reduction.^6,9

High-volume suction-When aerosols are created, high-volume suction can offer an effective means of reducing bio-aerosols and therefore viral particles in the air.¹⁶ Its use is an additional direct means of hazard reduction.^6,9

Management of gag reflexes-Because coughing spreads respiratory droplets further, efforts should be made to prevent coughing secondary to trigger of the gag reflex.⁶ Treatment for susceptible patients should be modified to address this concern. If patients tend to gag with intraoral imaging, extraoral imaging modalities can be considered. Sedation options may also be incorporated to minimize intraprocedural gagging.

An expanded list of procedural considerations is provided in Table 2.

Airflow

Although data exists on the plausibility of COVID-19 spread via ventilation systems,¹⁹ there is limited data on the specifics of appropriate airflow. That said, both the CDC and OSHA recommend certain minimum standards to maintain healthy airflow in a clinical setting.^7,9 Ventilation systems should be both inspected by a professional industrial hygienist or ventilation engineer and properly maintained. Airflow patterns should be explored, and efforts made to maximize the air changes per hour. Directional airflow should ideally occur from the outside in, and potentially contaminated air from clinical spaces should not recirculate into other portions of a facility. HVAC systems should have filtration optimized, and HEPA air filtration may be considered to potentially reduce the circulation of aerosols in clinical spaces.^7,9

The COVID-19 pandemic has provided the dental community a lesson in resilience and flexibility given rapidly changing information and policies. The use of evidence-based strategies by offices and practitioners to limit the entry of suspected or confirmed COVID-19 patients, as well as tactics to reduce the spread of COVID-19 from asymptomatic carriers, has largely prevented transmission in the dental setting. This has facilitated the continued delivery of safe and effective dental care in the midst of a pandemic. As the understanding of COVID-19 and its variants evolves, further adaptation will be necessary. That said, through the pandemic, the dental profession has proven itself to be adaptable in the face of great adversity.

Brooke Blicher, DMD, Certificate in Endodontics
Assistant Clinical Professor, Department of Endodontics, Tufts University School of Dental Medicine, Boston,Massachusetts; Clinical Instructor, Department of Restorative Dentistry and Biomaterials Science, Harvard School of Dental Medicine, Boston, Massachusetts; Instructor in Surgery, Dartmouth Medical School, Hanover, New Hampshire; Co-founder, Pulp Nonfiction Endodontics, LLC; Private Practicelimited to Endodontics, White River Junction, Vermont

Rebekah Lucier Pryles, DMD, Certificate in Endodontics
Assistant Clinical Professor, Department of Endodontics, Tufts University School of Dental Medicine, Boston, Massachusetts; Clinical Instructor, Department of Restorative Dentistry and Biomaterials Science, Harvard School of Dental Medicine, Boston, Massachusetts; Co-founder, Pulp Nonfiction Endodontics, LLC; Private Practice limited to Endodontics, White River Junction, Vermont

Jennie Kim
DMD Candidate, Harvard School of Dental Medicine, Boston, Massachusetts

Jarshen Lin, DDS, Certificate in Endodontics
Director of Predoctoral Endodontics, Department of Restorative Dentistry and Biomaterials Science, Harvard School of Dental Medicine, Boston, Massachusetts; Clinical Associate, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts