Efficacy of Dental Barriers in Aerosols and Splatters Reduction During an Ultrasonic Scaling: An In-vitro Study

Aerosol-generating procedures and associated control/mitigation measures: Position paper from the Canadian Dental Hygienists Association and the American Dental Hygienists' Association

Background

Since the outbreak of COVID-19, how to reduce the risk of spreading viruses and other microorganisms while performing aerosolgenerating procedures (AGPs) has become a challenging question within the dental and dental hygiene communities. The purpose of this position paper is to summarize the evidence of the effectiveness of various mitigation methods used to reduce the risk of infection transmission during AGPs in dentistry.

Methods

The authors searched 6 databases-MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, and Google Scholar-for relevant scientific evidence published between January 2012 and December 2022 to answer 6 research questions about the risk of transmission, methods, devices, and personal protective equipment (PPE) used to reduce contact with microbial pathogens and limit the spread of aerosols.

Results

A total of 78 studies fulfilled the eligibility criteria. The literature on the risk of infection transmission including SARS-CoV-2 between dental hygienists and their patients is limited. Although several mouthrinses are effective in reducing bacterial contaminations in aerosols, their effectiveness against SARS-CoV-2 is also limited. The combined use of eyewear, masks, and face shields is effective in preventing contamination of the facial and nasal region while performing AGPs. High-volume evacuation with or without an intraoral suction, low-volume evacuation, saliva ejector, and rubber dam (when appropriate) have shown effectiveness in reducing aerosol transmission beyond the generation site. Finally, the appropriate combination of ventilation and filtration in dental operatories is effective in limiting the spread of aerosols.

Discussion and Conclusion

Aerosols produced during clinical procedures can pose a risk of infection transmission between dental hygienists and their patients. The implementation of practices supported by available evidence will ensure greater patient and provider safety in oral health settings. More studies in oral health clinical environments would shape future practices and protocols, ultimately to ensure the delivery of safe clinical care.

Assessment of Infectious Diseases Risks From Dental Aerosols in Real-World Settings

Background

Infectious diseases physicians are leaders in assessing the health risks in a variety of community settings. An understudied area with substantial controversy is the safety of dental aerosols. Previous studies have used in vitro experimental designs and/or indirect measures to evaluate bacteria and viruses from dental surfaces. However, these findings may overestimate the occupational risks of dental aerosols. The purpose of this study was to directly measure dental aerosol composition to assess the health risks for dental healthcare personnel and patients.

Methods

We used a variety of aerosol instruments to capture and measure the bacterial, viral, and inorganic composition of aerosols during a variety of common dental procedures and in a variety of dental office layouts. Equipment was placed in close proximity to dentists during each procedure to best approximate the health risk hazards from the perspective of dental healthcare personnel. Devices used to capture aerosols were set at physiologic respiration rates. Oral suction devices were per the discretion of the dentist.

Results

We detected very few bacteria and no viruses in dental aerosols-regardless of office layout. The bacteria identified were most consistent with either environmental or oral microbiota, suggesting a low risk of transmission of viable pathogens from patients to dental healthcare personnel. When analyzing restorative procedures involving amalgam removal, we detected inorganic elements consistent with amalgam fillings.

Conclusions

Aerosols generating from dental procedures pose a low health risk for bacterial and likely viral pathogens when common aerosol mitigation interventions, such as suction devices, are employed.