The Covid-19 pandemic has created significant challenges for the oral healthcare sector. In April 2021, the New York Times reported that dentistry was the most at-risk profession compared to other professions, although to date, there were no reported cases of coronavirus transmission in a dental setting (Li et al., 2020).
Dentistry requires very close proximity to patients while performing procedures. Although dental professionals are very familiar with universal personal protective equipment, risk assessment, and infection control measures, the team should be more alert in creating and maintaining a safe environment for both the patients and themselves, given the high transmissibility of the disease. Patients would be more at ease in knowing that in addition to standard precautions, some special precautions had been implemented to ensure safety and avoidance of transmission of diseases in addition to standard precautions.
Dedicated screening of the patients, robust infection prevention and control procedures, good ventilation, and implementation of stringent disinfection protocol are crucial steps to prevent transmission of Covid-19. It is also important to limit the number of dental healthcare providers present during the procedure to only those essential for patient care and support.
We have been very rigorous in all our SOPs and successfully treated patients at the Oral Health Centre, Prince Court Medical Centre, without any transmission being reported to date. This article is intended to increase awareness among dental professionals and help patients and the public alike to acquire more confidence in seeking dental treatment during this difficult period.
Understanding aerosol transmission and its implications in dentistry are crucial. Most dental procedures generate aerosols, which could pose potential risks to the dental team and patients. The virus may be transmitted directly by inhalation of respiratory secretion droplets, as well as by contact with oral, eye mucous membranes, and nasal.
Large (>5 μm diameter) and small (≤5 μm diameter) droplets or aerosols are generated during a cough, sneeze, laugh, or talk. Larger droplet transmission requires close physical proximity between individuals for transmission due to gravity. However, small droplets of evaporated droplets have a low settling velocity, so they may remain in the air for a longer time before they can enter the respiratory tract or contaminate surfaces (WHO, 2014).
During dental procedures, excessive heat is created by rapidly rotating bur during high-speed handpiece usage due to friction. Thus, it is a universal consensus to use a water coolant to avoid damage to dental tissue, especially the pulp. In turn, the water coolant does generate aerosols, and when this is combined with bodily fluids in the oral cavity, such as blood and saliva, bioaerosols are created. These bioaerosols are commonly contaminated with bacteria and viruses that could be inhaled by dentists or patients (Jones and Brosseau, 2015).
Apart from following the principle of universal precautions, special additional measures targeted towards the reduction of aerosol transmission should also be taken to prevent and control the spread of disease. WHO guidelines, NHS England Guidance supported by local protective protocols proposed by the Ministry of Health advocated several special precautions in addition to the “standard precautions” applied in dental care settings.
We have also adopted the recommendations set forth by the British Orthodontic Society and strictly adhering to practicing these good practices in our dental settings at Prince Court Medical Centre.
According to the recommended guidelines, the protective measures that should be undertaken in a dental practice can be categorized into three phases:
1) Pre-dental treatment
2) During dental procedures
3) After dental treatment
It is advocated to delay non-urgent dental care, undertake remote risk assessment and triage of all patients before attending the practice, management of dental appointments via telehealth services, and active screening of dental staff must be carried out prior to the appointment.
Thorough medical history and assessment of health status at each recall visit are imperative in reducing the transmission risks. During the outbreak, targeted screening questions, which include personal, travel, and vaccination status, have to be established. Temperature screening and any lower respiratory tract symptoms should be closely monitored.
Providing a good ventilated waiting area and limiting the number of patients in the waiting room at the same time; as part of physical distancing. Blood pressure cuffs and thermometers should be disinfected with 70% ethyl alcohol after each use, as recommended by the WHO (2016).
Extending time between patients, as necessary, would allow for proper cleaning and decontamination of surgeries. Contaminated air in treatment areas is removed/filtered with commonly used high-volume evacuator (HVE) devices and the expensive high-efficiency particulate arrestor (HEPA) filters. In essence, a HEPA filter is an air filtration device that can remove 99.97% of the particles measuring 0.3 μm in diameter.
Whilst HVE filter is a suction device that helps remove air at a rate of up to 2.83 m3 per minute. It is the most efficient way to remove dental aerosols as they are generated and could reduce contamination caused by the operating site effectively by 90% (Narayana et al., 2016). At the Oral Health Centre, in addition to HVE and HEPA filtering system, we are also utilizing Ajax SP1000, a special Extra-Oral Suction system to clear away aerosols generated by dental procedures. It provides additional protection for the patient and staff from the spread of harmful bacteria and viruses generated from aerosols as much as 3000 liters per minute, by creating negative pressure around the patient’s head. It is a scientifically proven and effective solution to mitigate the risk posed by aerosols by rapid removal through a filtering system.
Practicing hand hygiene with the use of alcohol-based hand rubs (ABHRs) or handwashing with soap and water is the cornerstone of infection control in a healthcare setting. It should be given very serious attention in a dental setting at all times, even when no patient is present.
During most dental procedures, the spread of oral microorganisms is mostly directed towards the dentist’s face, particularly in the inner part of the eyes and around the nose, which are important areas for infection transmission. It is clinically evident that the virus could also be transmitted through contact with the mucous membranes in the eyes, as infectious droplets could easily contaminate the human conjunctival epithelium (Lu et al., 2020).
A certified particulate respirator (N95 or FFP2 or equivalent ) must be used during any aerosol-generating procedures (ultrasonic scaler, high-speed handpiece, and three-way-syringe). Face shield, or protective eyewear must be worn throughout the treatment and have to be disinfected between patients immediately post-treatment. A medical mask must be used at all times, at a minimum. A certified particulate respirator ( N95 or FFP2 or equivalent ) must be used during any aerosol-generating procedures (ultrasonic scaler, high-speed handpiece, and three-way-syringe).
A higher level of respiratory protection must be utilized (EU FFP3) if performing emergency dental treatment on suspected COVID-19 cases.
It is sensible to have a preference for disposable instruments where possible to reduce the likelihood of transmission via contaminated medical devices.
Pre-procedural mouth rinse is one of the most effective methods to prevent the spread of infections from aerosol-generating procedures in the dental setting and should be given a mandatory emphasis on the current pandemic SOP in dental clinics.
A meta-analysis showed that the use of preprocedural mouth rinse, including chlorhexidine (CHX), essential oils, and cetylpyridinium chloride (CPC), resulted in a mean reduction of 68.4% colony-forming units in dental aerosol (Marui et al., 2019). Evidence supports that chlorhexidine, either 0.2 % or 0.12% CHX is an effective antimicrobial solution for a pre-procedural mouth rinse. 0.05% CPC could be a good alternative for patients who develop other side effects such as tongue stains and mucosal irritation (Feres et al., 2010).
Rubber dam provides barrier protection from the primary source and potentially eliminates all pathogens from respiratory secretion. Although rubber dam is applied in all aerosol-generating procedures, in orthodontics, this is not entirely possible. However, AGPs in orthodontics are very few and could be avoided. For example, removal of adhesive during a rebonding of brackets could be done by using a low-speed handpiece instead of using high-speed handpieces.
Extra-oral imaging such as panoramic radiograph or cone-beam computed tomography (CBCT) should be used to prevent the cough or gag reflex that happens during intraoral imaging.
Droplets containing pathogens could be deposited on the surrounding surfaces during aerosol-generating procedures. Surfaces are disinfected thoroughly after each patient visit, especially surfaces close to the operating areas. However, they can be efficiently inactivated by surface disinfects within one minute. Recommended surface disinfectants recommended are based on 62%–71% ethanol, 0.5% hydrogen peroxide, and 0.1% (1 g/L) sodium hypochlorite (Kampf et al., 2020). Special care is also given to the management of laundry and medical waste after the treatment.
This pandemic has impacted how dental care can be safely delivered during the pandemic period and is expected to stimulate perpetual changes in the way dental care is delivered in the future. The widespread immunization will certainly improve the delivery of care in healthcare with new practical methods with revised standard operating procedures as we transition for recovery. The versatile daily situation during the pandemic requires continuous learning and updating of information amongst dental professionals to ensure the quality of oral healthcare is at an optimal level.