References

Jamal M, Shah M, Almarzooqi SH Overview of transnational recommendations for COVID-19 transmission control in dental care settings. Oral Dis. 2020; 1-10 https://doi.org/10.1111/odi.13431
Scottish Dental Clinical Effectiveness Programmme. Mitigation of aerosol generating procedures in dentistry – a rapid review. 2020. http://www.sdcep.org.uk/published-guidance/covid-19-practice-recovery/rapid-review-of-agps/ (accessed October 2020)
College of General Dentistry, Faculty of General Dental Practice. Implications of COVID-19 for the safe management of general dental practice – a practical guide. 2020. http://www.fgdp.org.uk/implications-covid-19-safe-management-general-dental-practice-practical-guide (accessed October 2020)
Samaranayake LP, Fakhruddin KS, Buranawat B, Panduwawala C. The efficacy of bio-aerosol reducing procedures used in dentistry: a systematic review. Preprints. 2020; https://doi.org/10.20944/preprints202006.0307.v1

Dental Practice during the Coronavirus Disease 2019 (COVID-19) Pandemic: Two Pathfinder Documents Point the Way

From Volume 47, Issue 10, November 2020 | Pages 878-882

Authors

Lakshman Samaranayake

DSc, DDS, FRCPath, FHKCPath, FDS RCS(Edin), FRACDS, FDS RCPS

Professor Emeritus, and Immediate-past Dean, Faculty of Dentistry, University of Hong Kong

Articles by Lakshman Samaranayake

Email Lakshman Samaranayake

Article

This edition of the COVID-19 Commentary reviews and summarizes two landmark advisory documents on practising clinical dentistry during the coronavirus disease 2019 (COVID-19) pandemic, and beyond. Both these, freely available, documents are essential reading for the whole dental team currently engaged in the delivery of dental care either in UK or elsewhere.

The insidious persistence of COVID-19 in many communities, including the UK, is a stark reminder that dentistry must ‘adapt and adopt’ new infection control measures to return to practice. Hence, numerous organizations and professional bodies have issued multiple recommendations on how best to mitigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection risk in routine dentistry.1 It is, therefore, comforting to note the publication of two excellent pathfinder documents pointing the way forward for the dental team on safe clinical practice during the COVID-19 pandemic and beyond. The first is a guidance document from the Scottish Dental Clinical Effectiveness Programme (SDCEP) entitled Mitigation of Aerosol Generating Procedures in Dentistry: A Rapid Review,2 sponsored by NHS Education, Scotland. As the name implies, this document (46 pages) specifically addresses and appraises the extant evidence on a number of key questions related to aerosol generating procedures (AGPs) in dentistry, and recommends mitigation measures. The second is an extensive document (76 pages) issued by the College of General Dentistry (CGD) and the Faculty of General Dental Practice (FGDP), UK that covers a broader spectrum of practice issues, entitled Implications of COVID-19 for the Safe Management of General Dental Practice: A Practical Guide.3

Both documents, compiled by two different teams of experts, are timely arrivals when the profession is returning to work after the prolonged ‘shut downs’ and service curtailments. They complement each other well, despite the minor variations in terminology and recommendations. One major difference in the terminology is in the SDCEP document, which adopts the term AGP throughout, while the CGD team opts for a broader risk-based approach and uses the term ‘aerosol generated exposure’ (AGE), instead of ‘aerosol generating procedure’ (AGP). This, they contend, was selected ‘…to promote a risk-based approach and encourages dental professionals to consider AGEs from a quantitative perspective, and to consider the risk from droplet and aerosol spread from natural exposures, such as gagging, coughing or spluttering’. In other words, AGE is a broader, all-encompassing term that incorporates the risks from both naturally produced and procedurally generated aerosols.

In the absence of a significant evidence base on mitigating SARS-CoV-2 spread in clinical dentistry, both these documents provide sensible and pragmatic guidance on how best to practise dentistry in the current environment, until new data on therapeutic and preventive strategies, such as vaccines, and point-of-care diagnostics, emerge, As stated by the authors in the preambles, they are essentially dynamic and ‘live’ documents that will be updated as new data emerge. Although difficult to summarize in a short paper of this nature, the commentary below provides some of the salient features of interest to the readership. Both documents are essential reading for all practitioners embarking on post-COVID-19 clinical dentistry. The SDCEP paper is discussed first, followed by the CGD document.

Mitigation of Aerosol Generating Procedures in Dentistry: A Rapid Review by the Scottish Dental Clinical Effectiveness Programme (SDCEP)

As the name implies, the major focus of this document is on three major AGPs that, for the sake of convenience, have been categorized into three areas:

Group A: Procedures that will produce aerosol particles <5 μm due to the use of high velocity powered instruments.

Group B: Procedures that may produce aerosol particles <5 μm due to the use of low velocity powered instruments.

Group C: Procedures that may produce splatter, but are unlikely to produce aerosol particles <5 μm and do not use powered instruments. Examples of these are provided in Table 1.


Group A Group B Group C
  • Ultrasonic scaler (including piezo)
  • High speed air/electric rotor (ie >60,000 rpm)
  • Piezo surgical handpiece
  • Air polishers
  • 3-in-1 syringe (air and water together)
  • 3-in-1 syringe (air-only/water-only)
  • Slow speed/electric handpiece (ie <60,000 rpm)
  • Prophylaxis with pumice (using slow speed handpiece/prophy cup)
  • Diathermy
  • Denture/ortho adjusting Using slow-speed handpiece
  • Surgical implant procedure
  • Surgical handpiece
  • Extraction (using forceps/elevator)
  • Hand scaling
  • Inhalation sedation
  • Impressions
  • Intra-oral radiographs
  • Local anaesthetic administration
  • Dental examination without 3-in-1 syringe
  • Re-cement crown
  • The section on AGPs is then followed up by a discussion of the procedural and environmental mitigation. These are then subdivided as: categorization of AGPs; high volume suction; rubber dam isolation; pre-procedural mouthrinses, antimicrobial coolants; ventilation; and air-cleaners. Then, each subsection is further discussed in terms of: (i) evidence summary and appraisal; (ii) considered judgement and agreed position; and (iii) the position statement. Thus, in total, there are six well-argued and articulated position statements for the foregoing subcategories from the SDCEP document, which are summarized in Table 2.


    Position statement Mitigation measure SDCEP Recommendation
    I High-volume suction Recommended
    II Use of rubber dam Recommended
    III Pre-procedural mouthrinses Not recommended
    IV Antimicrobial coolants Not recommended
    V Fallow time Recommended (for group A dental procedures: see Figure 1)
    VI Use of air cleaners Not recommended
  • The use of high-volume suction is recommended to reduce the potential risk of SARS-CoV-2 transmission associated with dental AGPs.
  • The use of rubber dam is recommended to reduce the potential risk of SARS-CoV-2 transmission associated with dental AGPs.
  • The use of pre-procedural mouthrinses is not recommended to reduce the potential risk of SARS-CoV-2 transmission associated with dental AGPs.
  • The use of antimicrobial coolants is not recommended to reduce the potential risk of SARS-CoV-2 transmission associated with dental AGPs.
  • A fallow time, where the clinic is vacant between patient treatment sessions, is recommended to reduce the potential risk of SARS-CoV-2 transmission associated with treatment that involves a Group A dental procedure.
  • The use of air cleaners to reduce the potential risk of SARS-CoV-2 transmission associated with dental AGPs is not recommended.
  • Position statements and fallow-time determination

    A well-argued case for all position statements can be found in the SDCEP document and they are not further discussed here, apart from the issue of fallow-time determination between two patient treatment sessions. In essence, SDCEP recommends that a minimum fallow time of 10 minutes must be applied after Group A procedures to include the time required for larger droplets to settle before environmental cleaning. It was surmised that, for Group B and C procedures (Table 1), the time for larger droplets to settle is accommodated within the standard infection control precautions as routinely used in dentistry. Additionally, they state dental procedures should not be conducted in a room that has no natural (ie a window) or mechanical ventilation.

    Of the foregoing six position statements, perhaps the most contentious is the allocation of fallow time for Group A dental procedures with high-powered instrumentation. Consensus on this has been difficult to reach due to the lack of a robust body of convincing data on aerosol spread of SARS-CoV-2 in clinical dental settings when AGPs are used.4 However, the SDCEP Working Group has grasped the nettle and proposed a pragmatic, fallow-time algorithm for Group A dental procedures, drawing from data on fundamental principles of viral spread, and other accessory mitigation procedures (Figure 1).

    Figure 1. A ready reckoner for determining fallow times for Group A dental procedures. Reproduced with the kind permission of SDCEP.

    The algorithm provides various fallow times based on a bi-pronged classification of the duration of Group A procedures as either (a) shorter, or (b) longer than 5 minutes. These are then re-classified into fallow periods ranging from 10 to 30 minutes, depending on various mitigation procedures, and the number of ambient hourly air changes of the clinic. Clearly, due to the multiple confounding factors that dictate the fallow time, the algorithm is necessarily complex. For this purpose, a fallow-time calculator (FTC)5 has been launched to facilitate the process, which enables dental professionals to determine, justify and also record the fallow period necessary following dental procedures carrying a higher risk of exposure to potentially infectious aerosols. It is free to use once registered at https://myftc.co.uk/register

    Implications of COVID-19 for the safe management of general dental practice – a practical guide by the College of General Dentistry Task Force3

    This is the second, recently released document that points the way for safe dental practice during the COVID-19 era. It is a compilation by the task force of the CGD under the auspices of the FGDP, UK.

    As mentioned, one of the key differences between the SDCEP and CGD document is the risk-based approach that the latter task force has adopted. Hence they opt to use the terminology ‘aerosol generated exposure’ (AGE), to substitute ‘aerosol generating procedure’ (AGP), owing to its broader remit that incorporates the risks from both naturally produced (eg coughing, sneezing), as well as procedurally generated aerosols.

    Further, the CGD document is more comprehensive and is far broader, encompassing the following key areas related to the ‘patient journey’:

  • Pre-appointment;
  • Patient attendance;
  • During treatment;
  • After treatment;
  • Management tasks, appertaining to administrative issues.
  • Each of the above sections comprise a summary narrative and a comprehensively tabulated matrix that could be used by practitioners as a quick reference to determine the risk level, and to identify measures that may be required in their practice in light of the alert level at that time.

    Each matrix has three columns as follows:

  • Domain: Aspects of the patient journey in question (see below);
  • Risk status and likelihood: Risk is categorized as negligible, minor, moderate, major, catastrophic), and likelihood is categorized as rare, unlikely, possible, likely, almost certain;
  • Risk-mitigation measures: The mitigating actions vis-à-vis the risk status (eg the most robust and stringent measures in place for risks with a rating of almost certain/catastrophic).
  • The risk mitigation measures in the last column are subclassified as A, B and C, wherein ‘A’ measures are aspirational and represent the best possible practice. ‘B’ (basic) measures represent a minimum standard that must be in place for the procedures/topic and reflect a balance of the safety relative to the risk and alert level, and practical operating and resourcing constraints. ‘C’ measures are conditional, that is they denote basic measures (minimum requirements) in specific circumstances.

    The document ends with two further sections on protecting vulnerable dental health care workers and frequently asked questions. The major points related to the five key areas discussed in detail in the document, are outlined below.

    Pre-appointment

  • Up-to-date information on COVID-19 made available online and widely disseminated to patients;
  • Patient communication ahead of dental practice visit;
  • Digital communication that should be encouraged with other available methods;
  • Administrative tasks should be undertaken ahead of the visit, where possible, and should include:
  • Patient questionnaire
  • COVID-19 screening
  • Medical history
  • Patient forms – FP17, estimate, consent
  • Information on payment
  • Review of technology should be considered with appropriate support and training put in place.
  • Patience attendance (pre-treatment)

  • Communicate arrangements and protocol for social distancing;
  • Minimize contamination of public areas by:
  • Providing antiseptic hand gel at entrance and exit
  • Minimizing waiting times in common areas
  • Adoption of high level of infection control and prevention
  • Protection of reception staff by social distancing, wearing of appropriate PPE, and/or barrier screens;
  • Appointment times tailored to new ways of working;
  • Temporal and spatial zoning for vulnerable patients;
  • Temperature checks deemed unreliable;
  • Testing seen as aspirational;
  • Ongoing training for all staff.
  • During treatment

  • AGE are a potential risk within the dental surgery;
  • Standard IPC protocols apply;
  • AGE needs to be considered as higher risk/lower risk;
  • Standard PPE for lower-risk AGE procedures considered as basic;
  • Higher-risk procedures require FFP2/3, visor and gown as BASIC;
  • Use of rubber dam and high-volume suction are important mitigating measures;
  • Appropriate fallow periods should be implemented following higher-risk AGE.
  • After treatment

  • Standard decontamination procedures should be followed;
  • Routine cleaning where the risk of AGE is low;
  • High AGE risk requires appropriate doffing of gown, with mask retained and removed outside the surgery;
  • Floor cleaning should be undertaken at the end of each high-risk AGE or the end of each session;
  • No paper records should be retained in the surgery while the risk of AGE is high or during the fallow period.
  • Management tasks

  • Protocols reviewed regularly to reflect the level of risk;
  • Identify members of staff to fulfil specific duties:
  • Management/governance lead
  • Health and wellbeing lead
  • Facilities prepared to support social distancing with appropriate signage/demarcation;
  • Risk assessment of staff prior to recommencement of work;
  • Access and occupational health support available for staff;
  • Appropriate training in place, including medical emergencies;
  • Stock control reviewed and ensure appropriate PPE available.
  • Conclusion

    In summary, the CGD Task Force document addresses a much broader range of subjects, while the SDCEP document focuses on a single aspect of practice protocol related to AGPs. The recommendations are a work in progress, and there is little doubt of their review and revision in the not too distant future due to the arrival of efficacious vaccines against SARS-CoV-2, point of care rapid diagnostic tests and, above all, new information on the infectivity and aerial and contact spread of this vicious virus. Finally, the summary commentary above does not do justice to either of these practical, timely and inclusive documents that should be considered essential reading for the whole dental team.