The uncertainty and chaos caused by the covid-19 pandemic raises many concerns for dental profession regarding practice safety and evidence-based guidelines. A wide array of recommendations available through scientific publications related to covid-19 and dental practice management, makes the task of presenting the most relevant and up to date literature more important than ever. The aim of this scoping review was to capture, document, and demonstrate all the relevant literature published so far on dental aspects of Covid-19 in order to serve as point for future recommendations and evidence-based guidelines for dental practices in this challenging time.
Considering that dental professionals are at higher risk of exposure to Covid-19, infection control has been discussed intensively in the literature 25, 26, 27, 30, 31, and 34. Ge Z et al argued that aerosol-generating dental procedures for suspected/confirmed Covid-19 patients have a particularly higher risk of infection transmission 27. To achieve optimal infection control, a better understanding of the chain of infection is crucial for the control and prevention of any infectious disease 38. The chain of infection requires a pathogen (virus or bacteria), natural reservoir (human or animal) to reside and multiply, which then leaves host through portal of exit, and enters into a susceptible host through portal of entry using some mode of transmission 38. Interrupting chain of infection anywhere along the chain will stop the spread of infection 38. The standard infection control provisions in dentistry can potentially serve as first line of defence for many dental professionals. However, considering highly contagious nature of SARS-Cov-2, extra protective measures should be adopted to prevent the transmission of Covid-19 disease 25.
We have identified 4 crucial phases which can be adopted to break the chain of transmission: (i) protocols for patient triage before treatment, (ii) patient evaluation upon arrival, (iii) during treatment, and (iv) after treatment. With many countries and different states in the US limiting dental procedures to emergency care during Covid-19 pandemic, it is important to establish the real need of emergency treatment 29, 31, 34. We found six out of the thirteen articles across different geographic locations (including China, USA, Italy) and practice settings, which implemented telephone triage using questionnaire to evaluate potential risk of SARS-Cov-2 transmission and type of dental care needed 25, 26, 27, 31, 32, 34. Emergency dental care for patients reporting symptoms of Covid-19, contact with Covid-19 infected individuals, or travel to highly epidemic regions in the past 14 days should be postponed and pharmacologic management of pain or infection should be considered 31. When the patient arrives at the clinic, the same questionnaire should be repeated and body temperature should be documented using non-contact thermometer 25, 31, 34. Patients with temperature > 100.4 F or 38oC should be postponed if possible or performed in an Airborne Infection Isolation Rooms (AIIRs) or negative pressure rooms 27, 31, 32. AIIRs are highly recommended for aerosol generating procedures. These are single patient isolated room with minimum 6 air changes per hour 27, 39. Air from these rooms is exhausted outside, away from areas of human traffic or gatherings or filtered through high efficiency particulate air (HEPA) filter, with negative pressure monitoring system held in place 27, 39. AIIRs or negative pressure rooms have been recommended and utilized in the management of corpses with suspected/confirmed Covid-19 patient’s 40. Waste management and psychological impact of Covid-19 on dental work force was another theme explored extensively in the literature.
Hand disinfection for patients, removal of shared objects (toys, drinks, magazines, etc.), 6 feet social distancing, limiting number of patients and use of mechanical or natural ventilation in the waiting area has been suggested to minimize risk of disease transmission to other patients and staff 27, 31, 34. If patient cannot go directly to the treatment area, then standard mask and a pair of gloves should be provided while waiting 31, 41. Ge Z et al suggested posting cough etiquette instructions at entrances and waiting area to promote respiratory hygiene 27. When preparing patient for the treatment, it has been suggested that pre-procedural mouth rinse with an oxidizing agent such as 1% hydrogen peroxide or 0.2% povidone iodine for 1 minute should reduce the viral load in aerosols 25, 31, 34, 42. Several studies reported that a common pre-procedural mouth rinse, chlorhexidine may not be effective against Sars-Cov-2, because there is lack of evidence or systemic data and virus is susceptible to oxidation 25, 27, 34. In addition, use of rubber dam and high-volume evacuation/suction (HVE) during aerosol generating restorative procedures can reduce airborne and surface contamination 25, 31, 32, 34. Use of less expensive high-volume evacuator (HVE) or expensive high efficiency particulate arrestor (HEPA) filters, if held within 6 -15 mm of aerosol generating tip can clean up to 90% and 99.99% contaminated air, respectively 27. A rubber dam should be used where possible, which can potentially eliminate all sources of aerosol contamination from blood or saliva by blocking the throat and soft tissue area, except the tooth/teeth undergoing treatment 43. An in-vitro trial conducted by Samaranayake et al found 70% reduction in aerosol with use of rubber dam during conservative pedodontic procedures 44. Peng et al recommends use of Carisolv, a minimally invasive chemo-mechanical removal of carious dentine and hand scaler for periodontal procedures where rubber dam is not feasible 25. Finally, the effectiveness of rubber dam as an isolation barrier is merely dependent on the placement skills of the provider and its’ technique sensitivity 45. Peng et al emphasized use of dental hand piece with anti-retraction/anti-reflux valve to prevent aspiration of contaminated bodily fluids into the tubes of hand-piece or dental unit and subsequent cross-infection 25. Although there is limited evidence on effectiveness of anti-retraction valve for eliminating risk of cross-infection, its use has been suggested as an additional preventive measure to reduce cross-contamination 46.
There has been much debate about choice of filtering face-piece (FFP), level 1 vs level 2 vs level 3 for aerosol and non-aerosol generating dental procedures. Some authors suggest wearing FFP1/standard surgical mask for non-aerosol generating procedures and FFP2/N95 or higher for aerosol generating procedures 25, 27 while others suggest FFP2/N95 for all procedures for both clinical and non-clinical staff 31, 34, and 35. A systematic review of clinical trials assessing effectiveness of N95 respirators in comparison to standard surgical mask found no additional protection in preventing influenza 45. The evidence from SARS-CoV research suggests that small infectious particles of up to 3 μm remain airborne indefinitely in an isolated room 48. Patients and dental professionals can be exposed via inhalation of sustained small airborne infectious particles, upon entering the room used to perform airborne generating procedures when minimal protection of standard surgical mask is used 25,35. Therefore, considering highly infectious nature of Sars-Cov-2 compared to influenza, we recommend use of FFP2/N95 for both clinical and dental assistants and all dental procedures. Every patient should be considered potentially contagious. Hand hygiene has been extensively emphasized as key factor in preventing cross-contamination, a two-before-and-three-after hand hygiene guideline recommended by CDC and WHO has been suggested 25, 27, 28, 31, and 34. Dental professionals should disinfect their hands with soap or 70 – 90 % alcohol before patient examination, before dental procedures, after touching the patient, after touching patient’s contaminated surrounding or instruments, and after bodily fluid exposure 25, 27. Eye protection with safety glasses and face shield has been suggested, which can be disinfected using 70% alcohol 25, 34. Alharbi et al recommends use of extra-oral radiographs such as orthopantomogram, and cone beam computer tomography over intraoral to prevent gag and excessive salivation 32. Overall, a layering approach including head covers, long-sleeved water-resistant gowns, shoe cover, level 2 FFP, and eye protection has been proposed for both clinical and dental assistant’s staff to significantly break the chain of infection 25, 27, 31, 34.
After the procedure is complete, disinfection of the treatment room and waiting area including doorknobs, chairs, desks, restrooms, and elevators between patients has been suggested to break the chain of transmission 27, 31, 34. Hospital-grade disinfectants including quaternary ammonium-based, phenol-based, and alcohol-based products such as 0.1% sodium hypochlorite or 70% isopropyl alcohol has shown evidence to be effective against coronaviruses 49, 50. Wei et al indicate that airborne aerosol particles of less than 50 μm can take up to 30 minutes to settle on the floor, while particles less than 3 μm may remain airborne indefinitely 48. It is also important to note that, research from Wuhan hospitals related to bio aerosol transmission of Covid-19 reveals high load of virus droplets on the floor and surfaces, indicating likelihood of fomite mediated, and that the dried large droplets may become airborne again 53,54. Thus, we recommend ventilating room for 30 minutes before disinfection or using high efficiency or HEPA filter air purifier, and possibly UVC light for small airborne particle 51, 52. It is important to clean/mop floor between patients especially after aerosol generating procedures and wearing shoe covers, to effectively disinfect treatment and waiting area 25,34,53,54. Dental providers need to consider best practices approach to create clean and safe environment for their staff and patients and to minimize risk of disease transmission. Notable consideration should be given to staff training, education, revision & reinforcement of infection control protocols. We suggest creating separate clinical and non-clinical area.
Waste management and psychological impact of Covid-19 on dental work force was another theme explored extensively in the literature. Treatment and disposal of medical waste pose indirect health risk due to environmental contamination, therefore it should be disposed-off in accordance with the protocols provided by the local health authorities. A temporary storage area should be assigned in the clinic for storage of medical waste 25. Reusable instruments should be adequately pre-treated using oxidizing disinfectant, cleaned, sterilized, and stored in accordance with the local health authorities’ protocol 25. Double-layered packing, appropriate labelling, and gooseneck ligation has been suggested for medical waste generated from suspected/confirmed cases of Covid-19 25. The contaminated disposable PPE including gloves, gowns, head covers should be safely disposed-off in a bag, within clinical area before entering non-clinical area. FFP level 2/3 mask should be worn by all staff members at all times.
Dental healthcare professionals are at high risk for acquiring and transmitting infection to their peers, families, and other patients due to possibility of exposure to suspected/confirmed covid-19 patients 36. The risk is substantial due to aerosol generating procedures observed during routine dental care leading to subsequent development of fear, anxiety, mental/psychological challenges among dental professionals posed by Covid-19 crisis 34, 36. This is especially important as emotional instability due to fear and anxiety can foster irrational behaviour and inadequate infection control practices 36. We identified four articles examining awareness, perception, attitudes, and behaviour among dental professionals regarding Covid-19 pandemic 28, 33, 36, 37. Khader et al conducted a cross-sectional study among 368 Jordanian dentists from different clinical settings to assess awareness, perception, and attitude regarding covid-19 and infection control practices 33. Jordanian dentists were found to have limited knowledge about right incubation period, social distancing and mask for patients in the waiting area, hand hygiene practices, protective clothing for clinical and non-clinical staff, and over 80% reported to avoid treatment for suspected/confirmed covid-19 cases amid to fear of contracting disease 33. Another study conducted by Ahmed et al surveying 669 dentists from 30 different countries reported almost 80% feared contracting covid-19 and would avoid treating suspected cases 36. This is further backed by scientific evidence available from previous research showing unwillingness of dental providers to treat patients with infectious diseases such as SARS, HIV, tuberculosis, and MERS 36, 37. Use of rubber dam and pre procedural mouth rinse with oxidizing agent were ignored by majority of dental providers 36. High level of anxiety was reported among dental professionals related to practice closure and subsequent economic implications 36. A study evaluating psychological stress experienced by Israeli dentists and dental hygienists during Covid-19 pandemic identified that elevated psychological distress was significantly associated with having an existing chronic medical condition, low self-efficacy score, and contracting Covid-19 from patients 37. The study further highlights that psychological distress among dental professionals may have long-term effects and recommends mental health education or workshops to enhance self-efficacy 37. The role of local authorities in providing procedural guidelines in the face of pandemic is vital to help healthcare providers in making informed decisions. Adequate knowledge of incubation period is essential to determine safe period in treating suspected Covid-19 patients 33. Use of rubber dam, protective clothing, and pre-procedural mouth rinse play a significant role to prevent cross-contamination 33.