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.
