Infection Control Practice Updates Since the COVID-19 Pandemic

Since the start of the COVID-19 pandemic, the dental health profession has been reexamining its infection control practices with the intention of tightening existing procedures and implementing updated protocols. In particular, the pandemic has spotlighted the need to update processes regarding aerosol and air quality management, hand hygiene, personal protective equipment, respiratory hygiene, sharps safety, operatory disinfection, and dental unit waterline maintenance. Many of these procedures are not new. The Centers for Disease Control and Prevention had already advised on almost all of these measures before the pandemic, and they are part of their standard guidelines. Unfortunately, many offices continue to neglect to follow these recommendations. An additional measure that is vital for dental offices to adopt is that of incorporating a trained infection control coordinator as part of the staff, who would serve as the key team member to ensure that up-to-date infection mitigation protocols are being followed and guarantee compliance with current regulations. This article provides a concise discussion of standard infection control precautions and practice updates and sheds light on why these practices are critical in the dental care setting.

Even before the COVID-19 pandemic, dentistry had robust infection control procedures in place.  Unfortun-ately, not every dental office followed all the recommended standard procedures.

However, the COVID-19 pandemic has served as an important "wake-up call" for many to tighten up their infection control practices. Similar to how the HIV/AIDS pandemic of the 1980s spawned a greater understanding of the spread of blood-borne pathogens, which led to the practice of routine wearing of gloves and masks by dental healthcare professionals, the COVID-19 health crisis has prompted the Centers for Disease Control and Prevention (CDC) to update its guidelines for protecting patients and healthcare personnel.

With COVID-19 infection, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), some affected individuals may become severely ill, while others may be asymptomatic (albeit they may still transmit the virus). The upper airways and lungs are identified as the primary sites of SARS-CoV-2 infection. Nevertheless, the virus has also been found present in the saliva and oral flora, potentially through several identified routes. Frequent liquid droplet exchange may be possible owing to the anatomical proximity of the lower and upper respiratory tract and oral cavity. SARS-CoV-2 may enter the oral cavity via gingival crevicular fluid, which contains serum proteins and thus viral components. New research has shown that the virus may rapidly infect salivary gland epithelial cells, indicating that salivary gland cells may play a critical role in virus transmission.

Excretion via the oral cavity and, therefore, airborne transmission amplification may occur via aerosols and aerosol-generating procedures, including respiratory droplets generated through talking, coughing, and sneezing of an infected patient. Transmission through fomites (materials or surfaces that are likely to transmit infection) can occur through interpersonal contact. Dental healthcare staff must have additional infection control measures in place to limit the risk of viral transmission.


With the discovery of new infectious diseases, transmission-based infection control protocols in oral healthcare need to be reexamined and adjusted accordingly. Transmission-based precautions are the second tier of basic infection control measures, which have been put in place to control or prevent the transfer of germs from one person to another in any healthcare setting to protect patients, their families, other visitors, and healthcare workers. They are used, alongside the usual standard precautions, when treating patients who may be infected or colonized with certain infectious agents, for which additional precautions are necessary to thoroughly prevent infection transmission. Owing to the highly infectious nature of SARS-CoV-2, individuals who are infected or suspected of being infected with this virus must undergo necessary transmission-based precautions to prevent disease transmission. These precautions must be revisited in light of the COVID-19 pandemic to tailor them specifically for the identified modes of transmission of SARS-CoV-2 in order to be effective in curtailing the spread of COVID-19. In addition, measures must be taken to ensure that dental practices understand the necessity of implementing these protocols for patient and staff safety.

While some transmission-based infection precautions have been updated for dental settings, the role of the infection control coordinator (ICC), crucial to mitigating infection risk in healthcare settings, has not been revised. With the onset of the COVID-19 pandemic, the ICC must also have a firm grasp on transmission-based measures. Despite the CDC's recommendations regarding the necessity of an ICC for almost 20 years now, incorporating a trained ICC is still not standard in many dental offices.

The ICC is the key team member to turn to during any infectious disease outbreak, as ICCs have relevant and ongoing training in infection prevention. They are responsible for daily and long-term oversight of an office's infection control strategy, ensuring that all policies, procedures, and practices are relevant and successful. Dental offices whose staff includes a trained ICC will be up to date on all current infection control measures and will therefore be equipped to develop and implement necessary standard operating procedures (SOPs) for the rest of the team to follow.9The ICC will keep an updated log of safety-related records, guaranteeing compliance with current regulations such as ensuring that all dental staff receive vaccinations and up-to-date training.


Aerosol and Air Quality Management

The pandemic has spotlighted the need for healthcare professionals to refocus on the current management of aerosols and air quality in dental settings. Dentistry has needed to take a hard look at the standard infection control procedures and protocols already in place, which have a proven track record of ensuring patient and staff safety when implemented correctly.

Along with standard precautions, a secondary tier of transmission-based precautions covering airborne transmissions may be necessary for some clinical situations, such as when a patient has a proven infection or is suspected of having a highly transmissible infection that routine procedures alone cannot entirely control. Aerosols carrying pathogens from the patient's saliva and oral fluids may be amplified into the air during the use of rotary dental and surgical equipment such as ultrasonic scalers. Transmission-based precautions for aerosols can be employed to prevent the spread of infectious pathogens that remain contagious when suspended in the air over extended distances.

In these cases, patients with infection or suspected of infection should be isolated in an Airborne Infection Isolation Room (AIIR) with regular air changes. Moreover, instead of relying on surgical masks, where much of the air and airborne organisms can enter at the sides, CDC recommendations advise using National Institute for Occupational Safety and Health (NIOSH)-approved, fit-tested N95 respirators and a complete respiratory protection program. The program should involve training and fit testing to verify that the respirator's edges and the wearer form an adequate seal so that no airborne pathogens may penetrate.

Because aerosols can remain suspended for up to 3 hours, it is crucial to perform a complete air change to filter out expired or contaminated air and facilitate the movement of "clean" air into the operatory, which can be achieved through ventilation with sufficient fallow time after aerosol-generating procedures (AGPs).A common technique used to assess air circulation is to determine the Air Changes per Hour (ACH) to calculate the frequency with which the air in the room is completely exchanged in the clinical space following each operation to minimize the risk of airborne infection,particularly if high-speed or ultrasonic devices were used.

Reducing aerosol dispersion is possible by modifying dental treatment practices, for example, through the use of rubber dams and engineering controls such as using portable high-efficiency particulate air (HEPA) filtration units immediately after AGPs as recommended by the CDC to capture pathogenic particles and reduce the risk of transmission.Rubber dams have been demonstrated to significantly reduce airborne particles by 70% within 1 m of the operational range.

It is also essential to be familiar with high-volume evacuation (HVE) tips and use them during AGPs. The use of HVE during AGPs has long been recommended, and the COVID-19 pandemic has merely highlighted that many dental professionals are not fully following protocols already in place. In order for a high-volume evacuator to be qualified as effective at minimizing bioaerosols, it must have an adequate bore size or opening diameter; bore size or opening diameter is thus a significant factor to consider. An opening of at least 8 mm or greater is recommended, as this can remove up to 100 cubic feet of air per minute. It should be noted that using a saliva ejector is insufficient, as it does not have the adequate opening size to be classified as a high-volume evacuator.

Additionally, the suction tip should never be placed more than 15 cm away from the central incisor teeth. It is vital to eliminate as much spatter, spray, and aerosol as possible at the point of use, regardless of whether there is a global pandemic. Aerosols must be eliminated as much as possible while they are being generated because they may remain suspended in the air for hours within the dental clinic, where dental care providers and patients may inhale them. A significant portion of these aerosols may also settle down on nearby surfaces, creating many contaminated areas and ultimately increasing the risk of infection.

Hand Hygiene

Hand hygiene has been a significant part of infection control since the 1980s, having taken more than 100 years to become accepted as an essential practice. Alcohol-based hand rubs (ABHR) are considered the most effective, simple, and cost-effective method of hand hygiene for preventing COVID-19 cross-transmission. However, even ordinary soap can make a difference, while an antibacterial soap can further enhance transmission prevention. Furthermore, handwashing must be performed at the beginning and end of the day. The World Health Organization (WHO) recommends ABHR formulations containing 80% ethanol and 75% isopropanol, as these have significant virucidal activity against SARS-CoV.19

*This article gives the reader CE credits