Safe protocol of resuming routine dental procedures in a tertiary care hospital setting post COVID-19 lockdown

2.1 Tele-health and receptionist-directed triage protocols

We used tele-health strategies to provide better patient care and to reduce risk of COVID-19 transmission. Patients were instructed to call and inform if they noticed any symptoms after dental treatment. Also, all patients were called twice after first and second week of hospital visit and asked about symptoms of COVID-19 virus as mean incubation period of COVID-19 is 5 days (range 2–14 days) [19]. Based on tele-health protocols, record was maintained about number of patients contracting COVID-19 infection following dental treatment. All HCPs were also monitored for signs and symptoms and advised to immediately self-isolate and remotely inform in case of any symptoms for further contact tracing.

2.2 Screening and triage of everyone entering hospital for signs and symptoms of COVID-19

COVID-19 sentinel was established at the single-entry point to the hospital facility. Emergency exit doors were used for exit separate from the entry doors. HCP in screening zone wore surgical face mask. Hand sanitisation was provided with 70% alcohol based disinfectant spray-bottles. Temperature was checked for everyone entering dental hospital with a non-contact thermometer and screening questionnaire was filled. Questionnaire was based on subjective symptoms as fever, dry cough, loss of taste and smell, myalgia, GI upset, previous history of COVID-19 infection, history of travel or contact with a COVID-19 infected person. Any person with fever ≥100.0 °F, suspected or confirmed COVID-19 infection was evaluated for urgency of dental care. According to the American Dental Association (ADA), these conditions include uncontrolled bleeding, facial space infection or cellulitis and facial trauma that compromises patient’s airway [20]. Suspected or confirmed COVID-19 infected patients presented only for acute pain and were provided pharmacologic treatment. Patient attendants were restricted from entering the facility except in the case of caregivers assisting handicapped individuals and parents accompanying children under the age of 14.

2.3 Health care worker screening

Temperature of HCPs before entry into the hospital at the beginning of the day was checked. HCPs were prohibited from entering or remaining in the workplace if they had fever of 100.4°F or greater (or reported feeling feverish), or if screening results indicated COVID-19 infection. Infected HCP self-isolated and contact tracing was done, followed by screening of contacts for COVID-19 infection. HCPs strictly followed the source control measures.

2.4 Universal source control measures

Source control measures were implemented by making it compulsory for all HCPs, patients and visitors to wear facemask or their own cloth face coverings upon arrival and throughout their stay at hospital facility. Patients and HCPs were educated about importance of hand hygiene before and after contact with face mask or cloth face covering. Visual alerts in form of posters were displayed at entrance, common areas (toilets and waiting area) and in strategic places (hallways, clinic entrance doors) in English and native language about COVID-19 awareness, wearing facemask for source control, social distancing and instructions about hand hygiene [12].

2.5 Seating area

Seating arrangement and markings were made in waiting area for patients. Also, for HCPs group activities and for breaks, rooms and seating areas were designated to ensure social distance of 6 feet at all times. Most of group healthcare activities were modified by implementation of virtual methods.

2.6 Universal use of personal protective equipment (PPE)

PPE used for dental procedures comprised surgical mask, eye protection (goggles), face shield, sterile gloves and sterilised surgical gowns. Hospital administration provided surgical masks for HCPs due to limited availability of KN95.

2.7 Donning and doffing zones

Donning zone and Doffing zone were established in separate designated rooms inside each department. HCPs conformed to following sequence while donning PPE [21]: Hand hygiene adhering to WHO’s hand hygiene instructions; Sterilized surgical gowns; Face mask; Eye-protection; Face shield; Hand hygiene again before wearing sterile gloves.

After dental procedures, HCPs removed the gloves, performed hand hygiene. Surgical gowns were disinfected with 70% ethanol sprays [22]. Goggles and face shields were removed and disinfected with 0.1% sodium hypochlorite for 1 min and then washed with lukewarm tap water followed by hand hygiene again [23, 24]. Gowns and masks were not changed for each procedure unless visibly or knowingly soiled by saliva or blood. As CDC recommends extended use of mask and gown as part of contingency and crisis capacity strategies for asymptomatic patients [17]. Gowns were removed in separate designated room for doffing and placed in yellow labelled container. These were sent to central sterile supply department (CSSD) for sterilization.

2.8 Infection control protocol for aerosol generating procedures

2.8.1 Air quality

Air quality was maintained via natural ventilation through 5–7 windows in each department and 1 door which were kept open throughout the day. WHO recommends 12 air changes per hour (ACH) for hospital-based setting [25] ACH in each department was calculated as [26]:

ACH = air speed ( m s - 1 ) x opening area ( m 2 ) x 3600 s Room volume ( m 3 )(1) Where,

Air speed was calculated using anemometer was 0.25m/s (at time of calm/no breeze)

Opening area is the area of the vent of all the windows in the room

3600 are the number of seconds in an hour

Room volume calculated by multiplying length, height and width

AGPs were performed in 2 departments each with 10–12 dental units. The departments where Prosthodontic and Restorative AGPs were performed had an ACH of 12/h, Oral Surgery and Periodontology had an ACH 25/h. Figure 1 shows architectural design and location of windows and dental units.

Additional measures that were taken included: Use of rubber dam (when applicable); Use of high-volume suction; Air-water (triple) syringe was used with caution.

OPEN IN VIEWER

Fig. 1

Architectural design of hospital floor displaying routes of natural ventilation through multiple open windows and doors located in opposing direction in each department, allowing adequate air exchanges per hour (ACH). Thus, fulfilling the criteria of 12 ACH recommended by WHO for hospital setting. Area of each window and door is 8 ft² and 37. 5 ft² respectively.

4.1 PPE variation (type of mask and gown used for AGPs) in asymptomatic patients

There has been controversy in the recommendation of type of mask used by HCPs for dental procedures. WHO, Public Health England and Swissnoso recommend KN95 respirator use only in suspected or confirmed COVID-19 patients during dental procedures [29–31], whereas CDC, the European Center for Disease Prevention and Control, and the German Robert Koch Institute recommend universal use of KN95 respirators for protection against COVID 19 [32–35]. However, a meta-analysis of 4 RCTs including 6418 patients did not provide any evidence that KN95 respirators were superior to medical/surgical masks for protecting healthcare workers against laboratory confirmed viral infection [36]. An anecdotal report describing no COVID-19 transmission in 35 HCW protected by surgical masks who were exposed to aerosol-generating procedures in the anesthesia department [37].

As in this study protocol, HCPs used surgical mask during dental procedures and only 1 HCP contracted COVID-19 infection. As Student t-test between two groups was insignificant, therefore it can be ascertained that the use of surgical mask is safe in asymptomatic patients for dental procedures. There has been variation in type of gown used in literature like isolation gowns, surgical gowns, and coveralls and each has different advantages and disadvantages [38, 39]. A literature review recommends use of disposable surgical gown [40], also recommended by Ministry of Health, Pakistan [18]. We decided to use sterilized surgical gowns as they effectively protect personnel and patients from cross contamination, are cost effective as they can be easily sterilised. Surgical gowns can be used safely for risk levels 1–4 [39].

4.2 Ventilation method

Ventilation of the treatment room is an important factor to ensure safety of AGPs. Ventilation is the process of providing outdoor air to a space or building by natural or mechanical means [41]. Healthcare facilities in both developed and resource-limited countries with favourable climatic conditions can use natural ventilation [42]. Other methods of ventilation for dental hospital are through-the-wall exhausts [43], in-line exhausts with ducts [44], HVAC systems with HEPA filters and negative pressure dental surgery [43], aerosol collectors [45], and UV light [46]. We used natural means of ventilation with sufficient ACH to achieve 99% clearance in less than 10 minutes.

4.3 Antimicrobial coolants and pre-procedural mouth rinse

Antimicrobial coolants and pre-procedural rinse were not used for AGPs due to limited sources as NHS Education of Scotland did not recommend its use based on literature review [47].