==== Front BMC Oral Health BMC Oral Health BMC Oral Health 1472-6831 BioMed Central London 1340 10.1186/s12903-020-01340-y Review A Pan-Canadian narrative review on the protocols for reopening dental services during the COVID-19 pandemic http://orcid.org/0000-0003-2437-4552Brondani Mario brondani@dentistry.ubc.ca 1 Cua Denise d.cua@alumni.ubc.ca 2 Maragha Tala tala.maragha@alumni.ubc.ca 1 Shayanfar Melody melody.shayanfar@alumni.ubc.ca 3 Mathu-Muju Kavita kmmuju@dentistry.ubc.ca 1 von Bergmann HsingChi hsingchi.von.bergmann@ubc.ca 1 Almeida Fernanda falmeida@dentistry.ubc.ca 1 Villanueva Jeannie jeannie.midmaindental@gmail.com 4 Alvarado Alexis Armando Vides lex.vides@vahs.life 5 Learey Stephen strathconahealth@vsb.bc.ca 6 Donnelly Leeann ldonnelly@dentistry.ubc.ca 2 1 grid.17091.3e0000 0001 2288 9830Department of Oral Health Sciences, Faculty of Dentistry, University of British Columbia, 116/2199 Wesbrook Mall, Vancouver, V6T 1Z3 Canada 2 grid.17091.3e0000 0001 2288 9830Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada 3 grid.17091.3e0000 0001 2288 9830Department of Psychology, Faculty of Science, University of British Columbia, Vancouver, Canada 4 MidMain Community Health Center, Vancouver, Canada 5 Vancouver Aboriginal Health Society, Vancouver, Canada 6 Strathcona Health Society, Vancouver, Canada 2 12 2020 2 12 2020 2020 20 35220 8 2020 22 11 2020 © The Author(s) 2020Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.The current coronavirus disease 2019 (COVID-19) pandemic is impacting the way in which dental services are provided. The aim of this narrative review was twofold: to summarize key areas from the Canadian protocols available for the reopening and restructuring of dental services across the country and to critically review these protocols based on existing evidence. A narrative review of the existing Canadian protocols, written in English and French, was undertaken between April 15 and July 13, 2020. The protocols were obtained by searching through regulatory bodies and websites from professional organizations, and from personal contacts through academic institutions and policy leaders. The data extraction form focused only on protocols related to dentistry, and the information was compiled by a hired assistant. Content was categorized via group discussions with the research team on eight areas: office management and procedures, patient and staff screening, treatment procedures, office layout, risk reduction, personal protective equipment, supporting information, and length and readability. Thirteen protocols were identified and offered substantial variation in the level of details provided. All but two protocols specified proper donning/doffing of personal protective equipment, while all protocols recommended daily monitoring of COVID-19 related signs and symptoms in staff and patients. They varied in terms of recommended mask types, eye and face shield protection, and head coverings. While all protocols aimed at restructuring emergency dental services, their recommendations were often not based on the published evidence. This narrative review summarized key areas from 13 provincial and territorial protocols in Canada to help oral health care providers plan the reopening of their services. The information conveyed across all documents was clear, but variance highlights the need for a coordinated effort to develop an evidence-based document for dental practitioners. Keywords Oral health careProtocolsCOVID-19SARS-CoV-2Narrative reviewEvidence-basedCanadahttp://dx.doi.org/10.13039/501100000233Genome British ColumbiaCOV092Brondani Mario Faculty of Dentistry, University of British Columbia2020 Summer Student AwardCua Denise issue-copyright-statement© The Author(s) 2020 ==== Body Background The World Health Organization (WHO) declared the novel coronavirus disease 2019 (COVID-19) a global pandemic on March 11, 2020. The disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in Wuhan, China in December 2019 [1, 2]. As of October 10, 2020, COVID-19 has spread to more than 200 countries and territories, caused over 1 million deaths and infected more than 35 million people globally. The pandemic also caused an unprecedented global financial crisis and recession [3], as most countries imposed internal lockdown measures, halted industrial and commercial production, and implemented border closures that caused severe disruptions to public and private services; these actions were implemented in order to minimize the spread of SARS-CoV-2 infections. One of the services greatly impacted by the pandemic has been the provision of oral health care, due to the close face-to-face proximity of dental professionals to patients and the known fact that the virus causing COVID-19 can be found in saliva droplets and aerosols – both of which are inevitable in dental procedures [1, 2, 4]. Therefore, the practice of dentistry is said to be at the highest risk for the transmission of SARS-CoV-2 [5, 6]. Although appropriate personal protective equipment (PPE) and office management and procedures are already integral components of dental care required to mitigate the risks of pathogen transmission, the decision was made to either discontinue elective procedures and attend to dental emergencies only or to close a dental practice altogether [7, 8]. The focus on emergency-only care was encouraged by the British Columbia Dental Association on March 16, 2020. Under the current pandemic reopening plan, an approach has been implemented to restructure the delivery of oral health care across Canada. Part of this restructuring includes the implementation of recommendations put forward by national and provincial governments and professional organizations in the form of guidelines, referred to herein as protocols. As suggested by Cantore and Ballini [9], dental providers should follow a firm protocol when delivering care. As different Canadian provinces and territories varied in the way they handled lockdowns, implemented testing, and curtailed general services, different levels of SARS-CoV-2 infection rates and COVID-19 development were observed, with Quebec showing more than 10,000 COVID-19 cases per 1 million population, and New Brunswick showing less than 300 COVID-19 cases per 1 million population (as of October 10, 2020). Similar variance was observed in different countries around the world, with the United States, Qatar, and Brazil showing more than 20,000 COVID-19 cases per 1 million population, and with New Zealand, South Korea, and Japan showing less than 1000 COVID-19 cases per 1 million population (infection rates refer to October 10, 2020) [10]. The extent to which these variations influenced the content of the Canadian protocols remains unknown. Uncertainties also exist among dental professionals on how to provide care during the COVID-19 pandemic [11]. In response to the need for guidance, this narrative review critically assessed the available Canadian provincial and territorial protocols in terms of content and the use of evidence-based information to better advise oral health care regulatory bodies, professionals, and decision makers. The aim of this narrative review was twofold: to summarize key messages on the reopening and restructuring of dental services across Canada and to critically review those protocols based on existing evidence. This study is part of a larger research project entitled “Structural preparedness during the COVID-19 pandemic and the provision of urgent oral health care” aimed to determining what preparations during an outbreak are necessary to provide oral heath care, how much guidance is given for these preparations, and the barriers and facilitators involved in these preparations. Methods A narrative review of the existing Canadian protocols regarding requirements for the reopening of oral health care services was undertaken between April 15 and July 13, 2020. Only protocols focusing on the practice of general dentistry were sought, both in English and French. Protocols aimed at restructuring the practice of dental hygienists, dental therapists, dental technicians, and denturists were excluded. Protocols focused on restructuring the practice of any of the dental specialties were also excluded. In addition, this narrative review excluded international guidelines for restructuring the practice of dentistry, even if they aided, in full or in part, in the development of any of the Canadian protocols. These protocols were excluded in order to offer a more focused critique using Canada as the context and to purposefully select a manageable number of protocols to be reviewed in a timely manner, given the urgency brought on by the pandemic. Within this narrative review, we aimed to look at different aspects of the protocols as described herein, identify areas of variance, and explore the extent to which evidence is being utilized (or not) to inform recommendations and guidance; the available evidence in these areas can be applicable to any jurisdiction or country when dealing with this novel coronavirus. Given the nature of a protocol as an official governing affairs’ document outlining professional procedures related to actions and treatments, it was likely that they would be available within the grey literature and not within search engines such as PubMed® (via the National Center for Biotechnology Information). Therefore, a search was conducted via Google Scholar, mailing lists from regulatory bodies, the websites of organized professions and the government, and personal contacts through academic institutions and dental policy leaders in Canada. Data extraction was performed by a hired research assistant (DC) with content being categorized during group discussions with members of the research team for consensus. Each protocol was assessed using a data extraction form developed by MB, LD, and DC based on the available literature, and included the following eight areas: office management and procedures (e.g., cleaning and disinfection), personal protective equipment (e.g., masks, facial shield, eye protection), patient and staff screening (e.g., signs and symptoms of COVID-19), transmission risk reduction (e.g., used of pre-procedural rinse, consulting a heating, ventilation, and air conditioning professional), procedures (e.g., types of clinical and non-clinical treatment the protocol is aimed for), supporting information (e.g., the recommendations are supported by citations), office layout (e.g., patient and staff flow, barriers), and length and readability (e.g., clarity, easiness to read). These eight areas were also used to structure the analysis of the protocols and present the findings. It was required that the protocols contain guidance on resuming dental care following closure of the services, or restructuring of dental care beyond emergencies, due to the COVID-19 outbreak. The protocols must also have focused on minimizing SARS-CoV-2 transmission and infection and needed to have been published or updated as of July 13, 2020. However, with the evolving nature of the COVID-19 pandemic on its second and more severe wave of infections, many protocols are continuously being updated; therefore, the information provided herein is subject to change. Results A total of 15 different protocols were found; however, only 13 were utilized here (Table 1), with each Canadian province and territory having their own protocol devised by the following groups: the Alberta Dental Association and College, the College of Dental Surgeons of British Columbia, the Manitoba Dental Association, the Royal College of Dental Surgeons of Ontario, the Dental Association of Prince Edward Island, the Ministère de la Santé et des Services Sociaux and the Université de Montréal for Quebec, the College of Dental Surgeons of Saskatchewan, the New Brunswick Dental Society, the Provincial Dental Board of Nova Scotia, the Newfoundland and Labrador Dental Board, the Dental Services from the Department of Health of the Government of Nunavut, the Government of the Northwest Territories, and the Government of the Yukon. Two additional protocols were found in British Columbia, but were not included in the analysis as they were later replaced by the College of Dental Surgeons of British Columbia protocol. We have summarized the recommendations for the eight areas found in each protocol (Table 1) (protocols can be found at https://www.diac.ca/wp-content/uploads/2020/05/National-Reopen-Strategy-.pdf).Table 1 Canadian protocols for the reopening and restructuring of dental services across different provinces and territories according to office management and procedures, patient and staff screening, treatment procedures, office layout, personal protective equipment, supporting information, and length and readability British Columbia Alberta Saskatchewan Manitoba Ontario Nova Scotia New Brunswick Newfoundland and Labrador Prince Edward Island Yukon Nunavut Quebec Northwest Territories May 15, 2020 June 12, 2020 July 13, 2020 May 22, 2020 May 31, 2020 July 3, 2020 Date N/A June 23, 2020 June 12, 2020 June 1, 2020 June 5, 2020 May 28, 2020 June 19, 2020 Office management and proceduresa Minimize access points ✓ N/S N/S ✓ ✓ N/S N/S N/S N/S N/S N/S N/S ✓ Remove non-essential items ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Patient wait in car/outside N/S N/S N/S N/S ✓ ✓ ✓ N/S ✓ N/S N/S ✓ N/S Signage upon entry/admission ✓ Consider ✓ ✓ ✓ N/S ✓ ✓ N/S ✓ ✓ ✓ ✓ Patient hand hygiene ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Patient face covering N/S N/S ✓ ✓ ✓ N/S ✓ N/S Consider ✓ ✓ ✓ Advise Patient Limit number of staff ✓ N/S ✓ N/S ✓ N/S ✓ N/S ✓ ✓ ✓ ✓ ✓ Limit number of people inside ✓ ✓ ✓ ✓ N/S N/S ✓ ✓ ✓ ✓ ✓ ✓ ✓ Stagger staff and patient schedule ✓ ✓ ✓ N/S ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ High-touch surfaces Clean regularly Clean and Disinfect 2x/daily Clean 2x/day Sanitize frequently Clean and disinfect 2x/day Disinfect regularly Clean and Disinfect frequently Disinfect 2x/day Clean 2x/day Clean 2x/day Clean and Disinfect 2x/day Clean daily Clean and Disinfect 2x/day Water lines Flush 20–30 secs (before and b/w pts) Shock after extended break N/S N/S Shock after extended break Flush 2 min (start of day) and 30 secs (after pts) N/S Shock after extended break N/S Shock after extended break Shock at start of each clinic visit Flush 2 min (start and end of day) Shock after extended break Patient and staff screeningc Patient screening ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Staff screening ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Treatment procedurese Patient risk assessment ✓ ✓ ✓ ✓ N/S N/S ✓ ✓ ✓ ✓ ✓ ✓ ✓ Pre-existing health conditions ✓ ✓ N/S N/S N/S N/S ✓ ✓ ✓ N/S ✓ N/S ✓ Age  > 70  > 65 Seniors Older person N/S N/S  > 65  > 60  > 60 N/S  > 60 N/S N/S Emergency ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Urgent ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Non-essential ✓ ✓ ✓ N/S ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ For C-19 + or suspect patients ✓ ✓ No No ✓ No No No No ✓ ✓ ✓ No Office layoutg Rearrange office for distancing ✓ ✓ ✓ ✓ N/S N/S ✓ ✓ ✓ ✓ ✓ ✓ ✓ Enclosed AGP room N/S N/S ✓ N/S ✓ N/S N/S N/S N/S ✓ ✓ ✓ ✓ Specified donning/doffing areas ✓ N/S ✓ N/S N/S N/S ✓ N/S N/S N/S N/S N/S ✓ Personal protective equipmentb NAGP  Mask type and ASTM level Surgical 2/3 Surgical 2/3 Surgical 2/3 Surgical 2/3 Surgical 2/3 Surgical level N/S Surgical 3 Surgical 2/3 Surgical 2/3 Surgical 2/3 Surgical 2/3 Surgical 2 or higher Surgical 2/3  Eye protect ✓ OR ✓ OR OR AND/OR ✓ OR OR OR OR OR OR  Face shield N/S N/S N/S  Office attire ✓ ✓ ✓ When possible ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓  Gown/lab coat N/S N/S N/S N/S N/S N/S N/S N/S ✓ ✓ ✓ ✓ ✓ AGP  Mask type and ASTM level N95 N95 N95/KN95 N95 N95 N95 N95 N95 N95 N95 N95 N95 N95 OR OR OR OR OR OR OR OR OR OR OR Surgical 3 + FS Surgical 3 + FS Surgical 2/3 + FS Surgical 3 + FS Surgical 2/3 + eye protection and/or FS Surgical Level N/S + FS Surgical 3 Surgical 2/3 + FS Surgical 3 Surgical 2/3 Surgical 2/3  Eye protect OR OR AND/OR OR AND/OR AND/OR ✓ ✓ OR OR AND/OR N/S OR  Face Shield ✓ ✓ ✓  Office attire ✓ ✓ N/S When possible ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓  Gown/lab coat ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓  Head cover ✓ ✓ ✓ ✓ N/S N/S ✓ N/S ✓ ✓ N/S N/S ✓  Booties ✓ N/S N/S NS ✓ N/S N/S ✓ N/S N/S N/S N/S N/S Transmission risk reductiond Proper donning/doffing ✓ ✓ ✓ N/S ✓ ✓ ✓ ✓ ✓ N/S ✓ ✓ ✓ Pre-procedural rinse (seconds) N/S 1% HO2 (30) 1% HO2 (60) HO2 1–1.5% HO2 OR 1% PI (60) 1% HO2 OR 0.5–2% PI (min 30) 1–1.5% HO2 (30–60) 1–1.5% HO2 (30–60) optional 1% HO2 (60) N/S 1–1.5% HO2 OR 1% PI (60) Antiseptic (60 or 2 × 30) 1% HO2 (60) Rubber dam ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ N/S ✓ ✓ ✓ HVE ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ N/S ✓ ✓ ✓ 4-handed dentistry N/S ✓ ✓ ✓ NS ✓ ✓ ✓ ✓ N/S N/S N/S ✓ Minimize AGP ✓ ✓ ✓ ✓ ✓ N/S N/S N/S ✓ ✓ ✓ ✓ ✓ Minimize intra-oral imaging ✓ N/S ✓ ✓ ✓ N/S ✓ ✓ ✓ N/S ✓ N/S ✓ HVAC/air filtration unit ✓ N/S ✓ N/S Consider N/S N/S Rec’d N/S ✓ ✓ ✓ ✓ Professional consult for HVAC ✓ N/S ✓ N/S ✓ N/S ✓ ✓ N/S ✓ ✓ ✓ ✓ Settling time b/w pts (min) N/S N/S 15 N/S 15 Not required N/S 15 10 N/S 15 N/S 15 Supportive informationf CDC or provincial health officers and ministries ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ N/S ✓ ✓ ✓ ✓ WHO N/S ✓ N/S ✓ ✓ ✓ N/S N/S N/S N/S N/S ✓ ✓ Occupational Safety Organizations Worksafe ✓ N/S N/S N/S N/S Worksafe CCOHS, NIOSH CCOHS N/S CCOHS WorkSafe OCPHO NIOSH Length and readabilityh Total number of pages 19 15 10 8 16 16 12 25 23 7 85 60 15  > 75% text ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ No ✓ PPE/procedure table N/A ✓ ✓ N/A ✓ ✓ N/A N/A ✓ ✓ ✓ ✓ ✓ Appendices/resources Links Links ✓ N/A Links Links Links Links Links N/A ✓ Imbedded Imbedded Printable resources N/A ✓ N/A ✓ ✓ ✓ ✓ ✓ ✓ N/A ✓ ✓ N/A References N/A N/A N/A ✓ ✓ ✓ N/A N/A ✓ ✓ ✓ ✓ Others Updates highlighted Updates highlighted Definitions provided Screening Questions and posters (hand hygiene, physical distancing) Glossary of terms Decision Trees Glossary of Terms and Acronyms Refers readers to Alberta Dental Assoc. and College for AGP IPC Manual Tips and Tricks Lab area Teaching environment In home care Definitions List of Emerg clinics N/C no changes, N/A not available, N/S not specified, AGP aerosol generating procedures, NAGP non-aerosol generating procedures, G gown, LC lab coat, FS face shield, ASTM American Society for Testing and Materials, CDC Centers for Disease Control and Prevention, WHO World Health Organization, HVE high volume equipment, HVAC heating, ventilation, and air conditioning, PI Povidone-iodine, Rec’d recommended, CCOHS Canadian Centre for Occupational Health and Safety, NIOSH National Institute for Occupational Safety and Health (United States of America), IPC Infection Prevention and Control Professional aOPE—Operatory protective equipment: refers mostly to equipment disinfection, functionality and maintenance including, but not limited to: use of disposable protective surface barriers, identification of the level of contaminants, scheduling of equipment and unit testing, routine check on medical supplies expiry dates, water line flush, storage of unnecessary items, and so on bPPE—Personal protective equipment: Refers to the use of surgical masks (level 1, 2 and 3) and/or respirators (N95/99/100), gowns, lab coats, gloves, eye protection (e.g., Google), facial protection (e.g., facial shield), or a combination of, or other (specified) cRefers to the screening of staff and patients for risk factors (close personal contact with a suspected or lab confirmed COVID-19 individual within the last 2 weeks, travel outside of the province or country in the previous 2 weeks) and symptoms (fever > 38C, cough, sore throat, shortness of breath, loss of the sense of smell, Flu-like symptoms, runny nose). Some protocols provided the actual form for the intake of this information dRefers to procedures and interventions aimed at preventing or eliminating the transmission of SARS-CoV-2 including proper donning/doffing, use of pre-procedural rinse, use of rubber damn, high volume suction unit, air filtration, and so on eRefers to the description of treatment procedures that the protocols are aimed for, from emergency to preventive, curative, surgical, and other treatment fRefers to source of information used to develop the protocol, including expert opinion, and evidence-based documents gRefers to specific recommendations for the layout of the clinic (e.g., waiting area space, front desk physical separation, and so on), and the operatory (e.g., negative/positive pressure room, floor-to-ceiling enclosure, and others) hRefers to the way the information is presented in terms of clarity and comprehension, use of infographics (tables, figures, schematics), easiness to follow, and so on Office management and procedures All protocols highlighted cleaning and disinfection recommendations following treatment of patients during the COVID-19 pandemic, with increased or enhanced routine cleaning already in use in dental practices. All protocols also stipulated the removal of non-essential items from waiting areas and across the office, and about informing patients on hand hygiene. Five protocols recommended minimizing access points, while signage related to COVID-19 and the appropriate precautions was recommended in 10 protocols. The majority of protocols recommended that physical distancing measures be adhered to, and that the number of people inside the practice be limited (n = 11 protocols). Six protocols recommended that water lines be shocked after an extended break, while eight protocols recommended cleaning and/or disinfecting high-touch surface areas at least twice a day. Patient and staff screening All 13 protocols recommended staff and patients be screened for known symptoms of COVID-19, including fever and cough; preferably, patients should be screened over the phone prior to the appointment and re-screened at the appointment date. Numerous protocols also appended the screening question form or provided a link to one. All protocols also had provisions that staff be provided with training on COVID-19 screening and risk transmission reduction. Treatment procedures All 13 protocols outlined the scope and intent of their recommendations for urgent and emergency care, while only one protocol did not specify if the recommendations would also apply to non-essential care. At least six protocols referred specifically to the need for risk assessment for the provision of oral health care to COVID-19-positive, or suspected positive, patients. Eight protocols focused on the age of older adults considered for risk assessment, with seven focusing on pre-existing conditions as part of this assessment, rather than age alone. The majority of protocols suggested booking appointments earlier in the day or on a separate day for known high-risk populations including seniors and those immune compromised. Office layout The office layout, from waiting areas to operatory and sterilization rooms, had the widest variation in terms of recommendations. All protocols recommended removing non-essential items (e.g., magazines, wall frames) from wherever possible in the office; however, only four protocols recommended designated areas for donning and doffing of personal protective equipment. In addition, seven protocols did not appear to recommend a specific closed operatory for aerosol-generating procedures. Personal protective equipment (PPE) All protocols recommend PPE as regular components of the provision of any dental care, including aerosol-generating (AGPs) and non-aerosol generating (NAGPs) procedures. However, they varied in terms of recommended mask types, eye and face shield protection, and head coverings. For AGPs, two protocols seemed to recommend both eye and face shield protection, while five advocated use of one or the other, but not both. ASTM (American Society for Testing and Materials) Level 2 or 3 surgical masks were suggested for NAGPs in all protocols, while six protocols recommended a N95 respirator or a Level 3 surgical mask and a face shield for AGPs. None of the protocols explicitly mentioned the use of negative pressure rooms for the management of aerosols and air circulation, nor did they refer to national clinical waste regulations or decontamination policies. Transmission risk reduction Eleven protocols recommended the use of a pre-procedural rinse for all patients, while eight specified various durations and concentrations of hydroperoxyl radical (HO2) as the actual rinsing solution to be used. Additionally, 12 protocols recommended the use of rubber dams and high-volume suction as frequently as possible. Eight protocols recommended consulting a heating, ventilation, and air conditioning (HVAC) professional to help determine the air changes per hour that could be utilized to calculate the settle time after AGPs with COVID-19-positive, or suspected positive, patients. Six protocols specified the amount of time needed for aerosol droplets to settle prior to disinfection of the room to reduce the potential for virus transmission. The use of four-handed dentistry was supported by eight protocols. Supporting information Most protocols (n = 12 protocols) appeared to be developed from professional agency recommendations (e.g., the Center for Disease Control and Prevention (CDC) and/or the WHO). The names of the authors were outlined in one protocol (from Quebec), while the others had the issuing organization as the author. None of the protocols indicated patient representation or involvement during the development process. Length and readability The lengths of the protocols were between 7 and 60 pages, with all but one having more than 75% pure text (excluding appendices). Some inconsistency in information was found within the same protocol. For example, when referring to the use of various mask levels and types for the same procedure, the same protocol mentioned “and/or”, then just “and”, and later suggested just “or”. Eleven protocols provided appendices or other resources to help with the implementation of their recommendations. One protocol also included useful “tips and tricks” and a list of all clinics providing emergency care for COVID-19-positive (confirmed), or suspected positive, patients. Numerous protocols seemed to differentiate their recommendations based on the SARS-CoV-2 infection status of the patient. If patients were positive for SARS-CoV-2 (confirmed), one protocol suggested they wait in the car or outside, two recommended using an enclosed operatory for AGPs during treatment, six endorsed the use of N95 (or higher) masks for any procedure performed, two preferred the use of a pre-procedural rinse and rubber dam, and two recommended minimizing the generation of aerosols and the need for intra-oral radiography (data not shown in Table 1). Discussion Our study sought to critically review and summarize eight key areas of the 13 protocols available in Canada for the reopening and restructuring of oral health care services across different provinces and territories. All protocols had similar recommendations in some areas (e.g., increased or enhanced routine cleaning, screening staff and patients for known symptoms of COVID-19, and use of PPE as regular components of the provision of any dental care) yet differed in others (e.g., risk assessment, face and head protection, types of pre-procedural rinses to be used). Although variation in the provision of services is related to a dentist’s personality and philosophy of care, the features of the practice, and patients’ preferences [12, 13], protocols are necessary for the profession and its services [14]—particularly during this unprecedented pandemic. This narrative review of the 13 protocols showed that ‘office management and procedures’ was not a term used explicitly, but rather it was implied when referring to waterline maintenance and disinfection of high-touch surfaces in the operatory rooms as part of the current daily routine in a dental office [15]. In the era of COVID-19, at least six protocols suggested increasing the frequency of this routine to effectively minimize cross-contamination [16, 17]. Across protocols, there was variation in the way the words “clean”, “sanitize” and “disinfect” were used when referring to high-touch surfaces; sanitization and disinfection are different and sanitization alone normally does not refer to eliminating viruses. Such variation might reflect the lack of consistency in which these terms are used in the literature pertaining to health care, with “clean and disinfect” as one encompassing term [18, 19], “clean/disinfecting” as interchangeable terms [20], and “cleaning” [21] or “disinfection” [22] used separately. Regardless of the term used, all protocols promoted patient safety and the prevention of the spread of pathogens. All protocols suggested daily screening of staff for COVID-19 symptoms and screening for patients at the time of booking, as well as upon arrival at the office for in-person care. The screening revolves around identifying potential risk factors and COVID-19 symptoms, including fever [23]. In terms of fever in particular, all protocols referred to 38 °C or above, but were not specific on how to measure this temperature (e.g., oral–sublingual, forehead–temporal artery, etc.); even thought a patient is considered febrile if the oral–sublingual temperature is above 37.5 °C and despite the fluctuations in internal body temperature regulating daily circadian rhythms [24]. Some protocols provided the actual information intake form, while others added to the current patient intake form. None of the protocols suggested using point-of-care diagnostic tests (via a nasopharyngeal swab for use with polymerase chain reaction-PCR-assays to detect viral RNA) or screening (via blood samples, to detect antibodies against SARS-CoV-2). Although other point-of-care tests are available to oral health care providers [25, 26], there is currently a lack of a gold standard to confirm positive COVID-19 cases [27] given that PCR tests seem to have a high false-negative rate [28, 29]. Nonetheless, SARS-CoV-2 diagnostic tools are continually being developed and tested to curtail widespread infection and its fatal respiratory complications [30]. PPE is included in the principles of universal, or standard, precautions for infection prevention and control in a dental practice, which treats every patient and their bodily fluids as infectious for any blood-borne pathogen, even when the patient is unaware of the infection or is asymptomatic [31]. PPE became mainstream in dentistry after the HIV epidemic in the 1980s [32]. As a universal precaution, the assumption is that all patients are treated equally without instigating perceived prejudice. Although HIV and SARS-CoV-2 have very different routes of transmission, Alharbi and colleagues suggest considering “every patient as a potential asymptomatic COVID-19 carrier” [33], so that proper precautions are always followed. As such, it was surprising to notice that a number of protocols described procedures or equipment that was only to be used with COVID-19-positive patients (symptom or laboratory confirmed) or they referred these patients to a hospital. Since as many as 50% of SARS-CoV-2 infections remain asymptomatic [34, 35] and the percentage of false-negative results vary dramatically [36, 37], we urge caution in approaching COVID-19-positive patients differently than their allegedly negative counterparts, given the potential for fear and discrimination [11]. Mask recommendations were consistent for NAGPs; however, there was variation when it came to AGPs. Many of the protocols that referenced the WHO recommendations for PPE mentioned use of a surgical ASTM Level 2 or 3 mask or an N95 respirator or its equivalent; however, two protocols only recommended N95 masks. Among the protocols that also included information about AGPs involving COVID-19-positive (confirmed or presumed), or suspected positive, patients, a N95 respirator or equivalent was recommended. However, current evidence shows that this may be an uncomfortable and unnecessary practice given that these masks are not found to be superior to surgical masks at preventing most viral respiratory infections [38]; however, research should now focus on the efficacy of other PPE (eye protection, facial shields, and clothing) in preventing the spread of SARS-CoV-2. Risk-reduction measures for transmission were quite comprehensive and similar across most protocols. However, not all protocols specified the need to use four-handed dentistry, employ air filtration, minimize intraoral radiographic imaging, use a particular pre-procedural mouth rinse, and monitor operatory settle times between patients. The four-handed technique has been part of almost all dental procedures, and is also believed to be beneficial for controlling SARS-CoV-2 infection [39]. None of the protocols suggested the use of negative-pressure rooms to help prevent airborne infectious particles from escaping the operatory into corridors and other rooms, as used in hospitals [40]. The implementation of negative-pressure rooms in dentistry seems to be a drastic and expensive approach for most general dental practices [41, 42]. Alternatively, AGP rooms with floor to ceiling walls (or the equivalent), good air filtration (e.g., HVAC systems), and sufficient air circulation have previously been suggested for the practice of dentistry [43]; these suggestions become especially important during the COVID-19 pandemic [44]. Six protocols did not specifically mention either air filtration or circulation measures. Six protocols specified 10 or 15 min as the amount of time needed for aerosol droplets to settle prior to disinfection of the room to reduce the potential for virus transmission, while the others did not specify a time. In a recent statement, the American Dental Association Task Force on Dental Practice Recovery stated that “while there is no strong evidence that supports a one-size-fits-all 15-min waiting period recommendation, it’s still very important to allow some time for aerosol droplets to settle prior to disinfection of the room to reduce the potential for virus transmission … dependent on a number of variables based on the individual practice setting.” [45] Given the emerging evidence of asymptomatic transmission of SARS-CoV-2, this is a particularly important area of research to ensure that guidelines for environmental controls in dental offices are realistic, effective, and consistent [46]. None of the protocols seemed to differentiate between settling time as “the amount of waiting time needed from dismissing the patient to starting to disinfect the operatory room” or as “the amount of waiting time needed in-between patients”; this time is highly dependent on air circulation, air filtration, the amount of aerosols generated, the COVID-19 status of the patient, and so on. As throat and salivary glands are likely sites for the replication and transmission of SARS-CoV-2 [47], O’Donnell and colleagues reviewed the literature on the use of mouth rinsing agents to advocate for more research on their use in reducing transmission of the novel coronavirus [48]. Although there is limited research on mouth rinses and SARS-CoV-2, eleven protocols advocated the pre-procedural use of HO2 (the hydroperoxyl radical, which is the protonated form of superoxide), povidone-iodine, or an antiseptic using a variety of concentrations and rinsing times. While some evidence exists that povidone-iodine may be superior in inactivating SARS-CoV-2 in vitro [49], more research is needed in this area to assess the in vivo effectiveness of pre-procedural rinses—as the virus is also shed in saliva which continues to be produced after the rinse. Our narrative review does recognize mouth rinses as useful adjuncts to plaque-control during oral hygiene, with various formulations ranging from alcohol-based chemical agents, chlorhexidine, cetylpyridinium chloride, and triclosan [50, 51]. At least nine protocols favoured the use of minimal and less invasive dental procedures that tend to minimize or eliminate the generation of aerosols. Such procedures could involve silver diamine fluoride therapies [52, 53] and atraumatic restoration techniques [54]. In fact, the COVID-19 pandemic might bring about a silver-lining moment for the profession, where there is an opportunity to favour, and be an advocate for, less invasive and conservative treatments, along with increasing the use of tele-dentistry [55]. All protocols were specific about their recommendations focused on both emergency and elective care; however, one did not specify if the recommendations would also apply to non-urgent or non-essential care. Although non-essential or elective oral health care treatments were strongly discouraged in Canada following the declaration of COVID-19 as a pandemic in March 2020 [56], they are included in 12 of the protocols, with 10 favouring NAGPs during the pandemic as suggested by Eden and colleagues [57]. In general, dental procedures are usually categorized as elective procedures (e.g., cosmetic dentistry), non-urgent procedures (e.g., replacement of non-decayed yet defective restorations), urgent conditions that can be managed with minimally invasive procedures and without aerosol generation (e.g., surgical postoperative dry socket dressing changes), urgent conditions that need to be managed with invasive and/or aerosol-generating procedures (e.g., extensive caries or defective restorations causing pain), and emergency management of life-threatening conditions (e.g., trauma involving facial bones that potentially compromises the patient’s airway) [21, 58]. Although the protocols did not use these definitions and/or exemplifications for the types of treatment, they likely meant to cover them in the restructuring of oral health care services in Canada beyond emergencies only. However, recent WHO guidance from August 3, 2020 appears to recommend postponing non-urgent and elective dental care [59] after citing a 2004 review article of in vitro studies showing that viruses may be present in dental instruments used in AGPs [60]. Such recommendations have to be taken with caution and, as suggested by Goldman, “a more balanced perspective is needed to curb excesses that become counterproductive” [61]. Routine and preventive care remain necessary for the early detection and control of oral diseases during the COVID-19 pandemic [62]. While booking appointments for seniors and those with underlying health conditions earlier in the day is meant to protect known high-risk populations, none of the protocols set priorities for testing patients suspected of having COVID-19 [30]. Office layout suggestions were quite consistent across the protocols regarding the need to facilitate physical distancing; however, less than half of the protocols specified the need for an AGP room or specific PPE donning and doffing areas. Some protocols may not have included these two important aspects because they were recommending minimal use of AGPs and/or not providing care to COVID-19-positive patients (confirmed or presumed). In addition, it is our assumption that asymptomatic transmission was not considered, as it was only articulated in one protocol. Throughout all 13 protocols the supporting information varied, with six citing the WHO, 10 referring to their respective provincial chapter of the CDC or government health officer/ministry, and three mentioning their corresponding WorkSafe® chapter. In addition, the recommendations seemed to be based on a very limited number of referenced publications, or none at all; regardless, the messages primarily remained clear and were either delivered concisely or extensively, with protocols ranging between 7 and 60 pages in length. Guidelines and policy recommendations, including protocols, should be grounded in evidence-based practice approaches and in precautionary principles, as suggested by Crosby and Crosby [63]. Without more evidence-based information on SARS-CoV-2 and oral health care, future studies should focus on the hard evidence that does exist and can reasonably be extrapolated to the provision of oral health care services; they should also include providers’ perspectives to elicit their views on the future of delivering oral health care during the COVID-19 pandemic. As the epidemiology of SARS-CoV-2 evolves, we should be able to develop a better understanding of the actual risks that AGPs pose to our patients, to staff, and to the public. Different levels of SARS-CoV-2 infection rates and of COVID-19 development were observed across Canada; however, the extent to which such variation influenced the content of the protocols presented herein is unknown, as is the effect of this variation on the dissimilarities across some of their recommendations. Moreover, consensus may take decades, particularly considering COVID-19 is a new disease that is still evolving; the scientific evidence we have thus far is not dogma, and our views need to be modified as new knowledge is produced and new experiences are presented. Our study is not without limitations. By focusing only on the restructuring of general dentistry practice, protocols aimed at restructuring the practice of dental hygienists, dental therapists, dental technicians, denturists, and dental specialties were excluded; we do recognize the recent debates around the differences in guidelines issued by different regulatory bodies, and the significant challenges that such differences may cause for those clinics in which dentists and dental hygienists and other providers work together. Future studies should include protocols that deal with the practice of allied oral health care services and the dental specialties during a pandemic. Its sole focus on Canada also excluded international protocols; although, we strongly believe that the evidence-base behind the recommendations of these protocols are indeed applicable to other countries given the universality of dental care and the impact of the COVID-19 pandemic. That is, the evidence behind a given recommendation (e.g., the use of specific masks, or the office layout) is available to better inform practitioners and researchers, regardless of where they are located. We did not assess protocols that were updated after the date shown in Table 1. Given the constant flow of new information around COVID-19, we may have missed protocols that contain new or more evidence-based data. Although the research team assessed each protocol using the form and met to discuss the findings, some of the information presented in Table 1 might have been misinterpreted. This is a possibility due to the contradictory information within some protocols and the ambiguous and open-for-interpretation information in others. Follow-up studies should focus on the extent to which such protocols were effective in curtailing the rate of SARS-CoV-2 infections within a population, and within the dental providers and staff themselves. Lastly, future studies should also focus on the knowledge dental health care personnel hold in understanding the implications of potential transmission of the SARS-CoV-2 virus in a dental clinic setting. Conclusions The constantly evolving knowledge and epidemiology around SARS-CoV-2 poses challenges to the development of protocols aimed at reopening and restructuring the delivery of oral health care in Canada and elsewhere; such challenges are even more worrisome during the second wave of even more severe infections underway in many countries, including Canada. The 13 protocols reviewed in this study aimed at limiting the transmission of the virus and were assessed in eight areas, from personal protective equipment to COVID-19 screening measures. Although all protocols seemed easy to read, it was apparent that good quality evidence-based information was limited, and non-referenced material was used. As new evidence-based knowledge is produced, these protocols and recommendations will need to continue to be updated and made available to the profession and their regulators so that operative policies are continuously introduced to better guide the dental profession. Dental providers and their staff need to keep themselves updated with new information regarding COVID-19 and the provision of oral health care for the safety of their patients and the community. Abbreviations AGPAerosol generating procedure ASTMAmerican Society for Testing and Materials BCBritish Columbia CDCCenters for Disease Control and Prevention COVID-19Coronavirus disease 2019 HIVHuman immunodeficiency virus HO2Hydroperoxyl radical HVACHeating, ventilation, and air conditioning NAGPNon-aerosol generating procedure PCRPolymerase chain reaction PPEPersonal protective equipment RNARibonucleic acid SARS-CoV-2Severe acute respiratory syndrome coronavirus 2 UPsUniversal precautions WHOWorld Health Organization Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Acknowledgements The authors are grateful to Dr. Angela Tether for her editorial contributions and to the Provincial Dental Officers who gave us access to some of the documents necessary to complete this narrative review. The authors attest to the originality of this research, and that it is not under publication consideration elsewhere. The authors gave their final approval, and agreed to be accountable for all aspects of the research. Authors’ contributions MB contributed to the study conception, design, data acquisition and interpretation, as well as drafting and critically revising the manuscript. DC and LD contributed to data acquisition and interpretation, and critically reviewed the manuscript. TM and MS contributed to review of the literature. KMM and HCvB contributed to data interpretation and critically reviewed the manuscript. FA, JV, AVAA, and SL contributed to the revision of the manuscript. All authors read and approved the final manuscript. Funding This study was funded by Genome BC’s Rapid Response Funding for COVID-19 Research and Innovation Projects # COV092, and by the UBC Faculty of Dentistry 2020 Undergraduate Student Summer Research Award. The funding organizations were not involved in the design of the study, the collection, analysis, and interpretation of data, or in writing the manuscript. Availability of data and materials The 13 protocols with data that supported the findings of this study are available from the Office of the Chief Dental Officer of Canada, at https://www.diac.ca/wp-content/uploads/2020/05/National-Reopen-Strategy-.pdf, last updated on May 22 2020. Ethical approval and consent to participate The University of British Columbia Research Information Systems (RISe) ethical approval was obtained (# H20-01147). Consent to participate was not applicable. Consent for publication Not applicable. Competing interests The authors declare no conflict of interest and have consented to have the manuscript submitted for publication. ==== Refs References 1. Zhu N Zhang D Wang W Li X Yang B Song J A novel coronavirus from patients with pneumonia in China, 2019 N Engl J Med 2020 382 8 727 733 10.1056/NEJMoa2001017 31978945 2. del Rio C Malani PN COVID-19—new insights on a rapidly changing epidemic J Am Med Assoc 2020 323 14 1339 1340 10.1001/jama.2020.3072 3. Nicola M Alsafi Z Sohrabi C Kerwan A Al-Jabir A Iosifidis C The socio-economic implications of the coronavirus and COVID-19 pandemic: a review Int J Surg 2020 78 185 193 10.1016/j.ijsu.2020.04.018 32305533 4. Setti L Passarini F de Gennaro G Barbieri P Perrone MG Borelli M Airborne transmission route of COVOD-19: why 2 meters/6 feet of inter-personal distance could not be enough Int J Environ Res Public Health 2020 17 8 2932 10.3390/ijerph17082932 5. Barabari P Moharamzadeh K Novel coronavirus (COVID-19) and Dentistry-A comprehensive review of literature Dent J 2020 8 2 53 10.3390/dj8020053 6. Cirillo N COVID-19 outbreak: succinct advice for dentists and oral healthcare professionals Clin Oral Investig. 2020 24 7 2529 2535 10.1007/s00784-020-03323-3 7. Coulthard P Dentistry and coronavirus (COVID-19)—moral decision-making Br Dent J 2020 228 7 503 505 10.1038/s41415-020-1482-1 32277203 8. Dave M Seoudi N Coulthard P Urgent dental care for patients during the COVID-19 pandemic Lancet 2020 395 1257 10.1016/S0140-6736(20)30806-0 9. Cantore S Ballini A Coronavirus disease 2019 (COVID-19) pandemic burst and its relevant consequences in dental practice Open Dent J 2020 14 111 112 10.2174/1874210602014010111 10. The Worldometer. COVID-19 Coronavirus Pandemic. Available at: https://www.worldometers.info/coronavirus/?utm_campaign=homeAdvegas1? Assessed October 10, 2020. 11. Brondani M Donnelly L The HIV and SARS-CoV-2 parallel in dentistry from the perspectives of the oral health care team J Clin Transl Res 2020 10.1177/2380084420961089 12. Bader JD Shugars DA Variation, treatment outcomes, and practice guidelines in dental practice J Dent Educ 1995 59 1 61 95 10.1002/j.0022-0337.1995.59.1.tb02920.x 7884074 13. Brennan DS Spencer AJ The role of dentist, practice and patient factors in the provision of dental services Commun Dent Oral Epidemiol 2005 33 3 181 195 10.1111/j.1600-0528.2005.00207.x 14. de Rooij D Belfrold E Eilers R Roskamps D Swaan C Timen A Qualitative research: institutional preparedness during threats of infections disease outbreaks BioMed Res Int 2020 2020 1 10 10.1155/2020/5861894 15. Roberts MC Soge OO Horst JA Ly KA Milgrom P Methicillin-resistant Staphylococcus aureus from dental school clinic surfaces and students Am J Infect Control 2011 39 8 628 632 10.1016/j.ajic.2010.11.007 21962840 16. Cobrado L Silva-Dias A Azevedo MM Rodrigues AG High-touch surfaces: microbial neighbours at hand Eur J Clin Microbiol Infect Dis 2017 36 11 2053 2062 10.1007/s10096-017-3042-4 28647859 17. Casini B Righi A de Feo N Totaro M Giorgi S Zezza L Improving cleaning and disinfection of high-touch surfaces in intensive care during carbapenem-resistant Acinetobacter baumannii endemo-epidemic situations Int J Environ Res Public Health 2018 15 10 2305 10.3390/ijerph15102305 18. Woltering R Hoffmann G Isermann J Heudorf U Surface cleaning and disinfection in the hospital. Improvement by objective monitoring and intervention Gesundheitswesen 2016 78 11 759 764 26107964 19. Quinn MM, Henneberger PK, National Institute for Occupational Safety and Health (NIOSH), National Occupational Research Agenda (NORA) Cleaning and Disinfecting in Healthcare Working Group, Braun B, Delclos GL, et al. Cleaning and disinfecting environmental surfaces in health care: Toward an integrated framework for infection and occupational illness prevention. Am J Infect Control. 2015;43(5):424–34. 20. Rutala WA Weber DJ Disinfectants used for environmental disinfection and new room decontamination technology Am J Infect Control 2013 41 5 Suppl S36 41 10.1016/j.ajic.2012.11.006 23622746 21. Bell-West SC Breaking the chain: strategies for effective terminal cleaning Health Facil Manag 2014 27 4 45 47 22. Carling P Methods for assessing the adequacy of practice and improving room disinfection Am J Infect Control 2013 41 5 S20 S25 10.1016/j.ajic.2013.01.003 23622743 23. Fu L Wang B Yuan T Chen X Ao Y Fitzpatrick T Clinical characteristics of coronavirus disease 2019 (COVID-19) in China: a systematic review and meta-analysis J Infect 2020 80 6 656 665 10.1016/j.jinf.2020.03.041 32283155 24. Del Bene VE. Chapter 218 - Temperature. In: Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Walker HK, Hall WD, Hurst JW, editors. Boston: Butterworths; 1990. 25. Brondani M Chang SM Are we ready for HIV screening in dental clinics? J Can Dent Assoc 2014 80 e58 25437938 26. Brondani MA Chang S Donnelly L Assessing patients' attitudes to opt-out HIV rapid screening in community dental clinics: a cross-sectional Canadian experience BMC Res Notes 2016 9 264 10.1186/s13104-016-2067-6 27165490 27. Alberta Health Services. COVID-19 Scientific Advisory Group Rapid Response Report. 2020; Available at: https://www.albertahealthservices.ca/assets/info/ppih/if-ppih-covid-19-sag-comparison-of-testing-sites-rapid-review.pdf. Accessed August, 2020. 28. Pan Y Long L Zhang D Yuan T Cui S Yang P Potential false-negative nucleic acid testing results for severe acute respiratory syndrome coronavirus 2 from thermal inactivation of samples with low viral loads Clin Chem 2020 66 6 794 801 10.1093/clinchem/hvaa091 32246822 29. Xiao AT Tong YX Zhang S False-negative of RT-PCR and prolonged nucleic acid conversion in COVID-19: rather than recurrence J Med Virol 2020 2020 1 2 30. Charitos IA Ballini A Bottalico L Cantore S Passarelli PC Inchingolo F D'Addona A Santacroce L Special features of SARS-CoV-2 in daily practice World J Clin Cases 2020 8 18 3920 3933 10.12998/wjcc.v8.i18.3920 33024749 31. McCarthy GM Universal precautions J Can Dent Assoc 2000 66 10 556 557 12584778 32. DePaola LG Managing the care of patients infected with bloodborne diseases J Am Dent Assoc 2003 134 3 350 358 10.14219/jada.archive.2003.0166 12699050 33. Alharbi A Alharbi S Alqaidib S Guidelines for dental care provision during the COVID-19 pandemic Saudi Dent J 2020 32 4 181 186 10.1016/j.sdentj.2020.04.001 32292260 34. Nishiura H Kobayashi T Miyama T Suzuki A Jung SM Hayashi K Kinoshita R Yang Y Yuan B Akhmetzhanov AR Linton NM Estimation of the asymptomatic ratio of novel coronavirus infections (COVID-19) Int J Infect Dis 2020 94 154 10.1016/j.ijid.2020.03.020 32179137 35. Mizumoto K, Kagaya K, Zarebski A. Estimating the asymptomatic proportion of 2019 novel coronavirus onboard the Princess Cruises Ship, Yokohama, Japan, 2020. Euro Surveill. 2020;25, 10. 36. Kucirka LM, Lauer SA, Laeyendecker O, Boon D, Lessler J. Variation in false-negative rate of reverse transcriptase polymerase chain reaction–based SARS-CoV-2 tests by time since exposure. Ann Intern Med. 2020 May 23. 37. West CP, Montori VM, Sampathkumar P. COVID-19 testing: the threat of false-negative results. In Mayo Clinic Proceedings 2020 Jun 1 (Vol. 95, No. 6, pp. 1127–1129). Elsevier. 38. Jefferson T Foxlee R Mar CD Dooley L Ferroni E Hewak B Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review BMJ 2008 336 7635 77 80 10.1136/bmj.39393.510347.BE 18042961 39. Meng L Hua F Bian Z Coronavirus disease 2019 (COVID-19): emerging and future challenges for dental and oral medicine J Dent Res 2020 99 5 481 487 10.1177/0022034520914246 32162995 40. Anderson J, Geeslin A, Streife A. Airborne Infectious Disease Management Methods for Temporary Negative Pressure Isolation. 2020; Available at: https://www.health.state.mn.us/communities/ep/surge/infectious/airbornenegative.pdf Accessed Aug. 5, 2020. 41. Halepas S Ferneini EM A pinch of prevention is worth a pound of cure: proactive dentistry in the wake of COVID-19 J Oral Maxillofac Surg 2020 78 6 860 861 10.1016/j.joms.2020.03.036 32302529 42. Ather A Patel B Ruparel NB Diogenes A Hargreaves KM Coronavirus disease 19 (COVID-19): implications for clinical dental care J Endod 2020 46 5 584 595 10.1016/j.joen.2020.03.008 32273156 43. Chen C, Zhao B, Cui W, Dong L, An N, Ouyang X. The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics. J R Soc Interface. 2010 2009;7(48):1105–1118. 44. Zhao B Liu Y Chen C Air purifiers: a supplementary measure to remove airborne SARS-CoV-2 Build Environ 2020 177 106918 10.1016/j.buildenv.2020.106918 32336870 45. Burger D. ADA responds to change from CDC on waiting period length. 2020; Available at: https://www.ada.org/en/publications/ada-news/2020-archive/june/ada-responds-to-change-from-cdc-on-waiting-period-length Accessed Aug, 2020. 46. Furukawa NW Brooks JT Sobel J Evidence supporting transmission of severe acute respiratory syndrome coronavirus 2 while presymptomatic or asymptomatic Emerg Infect Dis 2020 26 7 10.3201/eid2607.201595 47. To KK Tsang OT Leung W Tam AR Wu T Lung DC Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study The Lancet Infect Dis 2020 20 5 565 574 10.1016/S1473-3099(20)30196-1 32213337 48. O’Donnell VB Thomas D Stanton R Maillard J Murphy RC Jones SA Potential role of oral rinses targeting the viral lipid envelope in SARS-CoV-2 infection Function 2020 1 1 zqaa002 10.1093/function/zqaa002 33215159 49. Bidra AS Pelletier JS Westover JB Frank S Brown SM Tessema B Rapid in-vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using povidone-iodine oral antiseptic rinse J Prosthodont 2020 29 6 529 533 10.1111/jopr.13209 32511851 50. Cantore S Ballini A Mori G Dibello V Marrelli M Mirgaldi R De Vito D Tatullo M Anti-plaque and antimicrobial efficiency of different oral rinses in a 3-day plaque accumulation model J Biol Regul Homeost Agents 2016 30 1173 1178 28078871 51. Van der Weijden FA Van der Sluijs E Ciancio SG Slot DE Can chemical mouthwash agents achieve plaque/gingivitis control? Dent Clin North Am 2015 59 4 799 829 10.1016/j.cden.2015.06.002 26427569 52. Seifo N Robertson M MacLean J Blain K Grosse S Milne R The use of silver diamine fluoride (SDF) in dental practice Br Dent J 2020 228 2 75 81 10.1038/s41415-020-1203-9 31980777 53. Brondani M, Siarkoski M, Alibrahim I, Ribeiro CCC, Mathu-Muju K, Donnelly L, Alves CMC. The state of the art in teaching caries control agents in Canada. J Can Dent Assoc. Forthcoming 2020. 54. Molina GF Cabral RJ Frencken JE The ART approach: clinical aspects reviewed J Appl Oral Sci. 2009 17 Suppl 89 98 10.1590/S1678-77572009000700016 21499662 55. Brondani M Donnelly L Impact of COVID-19 pandemic upon undergraduate dental geriatric education J Dent Educ. 2020 1 8 10.1002/jdd.12302 56. British Columbia Dental Association (BCDA). https://www.bcdental.org/bcda-statement-coronavirus/. Accessed 4 July 2020. 57. Eden E Frencken J Gao S Horst JA Innes N Managing dental caries against the backdrop of COVID-19: approaches to reduce aerosol generation Br Dent J 2020 229 411 416 10.1038/s41415-020-2153-y 33037360 58. Frichembruder K, Mello dos Santos C, Neves Hugo F. Dental emergency: scoping review. PLOS ONE 2020;15(2):e0222248. 59. The World Health Organization (WHO). https://apps.who.int/iris/bitstream/handle/10665/333625/WHO-2019-nCoV-Oral_health-2020.1-eng.pdf Accessed 13 August 2020. 60. Harrel S Molinari J Aerosols and splatter in dentistry: a brief review of the literature and infection control implications JADA 2004 135 429 437 15127864 61. Goldman E Exaggerated risk of transmission of COVID-19 by fomites The Lancet 2020 20 892 893 10.1016/S1473-3099(20)30561-2 32628907 62. FDI World Dental Federation. https://www.fdiworlddental.org/news/20200814/fdi-responds-to-whos-latest-guidance-on-the-provision-of-oral-health-services-in-the Accessed August 14, 2020. 63. Crosby L Crosby E Applying the precautionary principle to personal protective equipment (PPE) guidance during the COVID-19 pandemic: did we learn the lessons of SARS? Can J Anaesth 2020 67 10 1327 1332 10.1007/s12630-020-01760-y 32666423