- The Faculty of General Dental Practice (FGDP) updated its guidance on the implications of COVID-19 and the safe management of dental practices on 2 October 2020.
- It has developed an online Fallow Time Calculator to support dental health care workers.
- There is additional information in the updated guidance on safety measures to prevent the spread of COVID-19.
On 2 October 2020, the FGDP updated its guidance on the implications of COVID-19 and the safe management of dental practices. It strongly encourages all dental professionals to read these guidelines and consider how to adopt them within their own practice.
Section 1: Pre-appointment
The only change to this section applies to locations where there are the highest local risk levels. Practices should consider using appropriate signage at the entrance doors, with the possible (re-)introduction of a closed-door policy to minimise the risk of infection being transmitted within the practice. Use of the NHS COVID-19 Test and Trace app may be helpful in determining local risk levels.
Section 2: Patient attendance (pre-treatment)
To minimise the risk of contamination, patients will be asked to comply with the practice’s Standard Operating Procedures (SOP), based on its updated infection control and prevention policies. These policies should include, but not be limited to, using antiseptic hand gel on entry, installing clear signage on hand hygiene when using toilet facilities, and promoting rigorous infection control and prevention standards. Practices should consider using safety screens at the reception desk as an effective method of protecting both staff and patients. They should also consider the routine use of surgical masks by all reception staff, in addition to strict social distancing protocols.
Universal temperature checks have been widely advocated, but some methods of temperature testing (such as the non-contact method) have been shown to be unreliable. Temperature checks may be appropriate as part of a risk assessment or for staff or patients who are feeling unwell, but are not recommended as a routine screening tool.
There have been significant advances in the methods for antigen and antibody testing, which will hopefully allow for rapid screening for COVID-19 in dental settings in the future. These techniques are still being evaluated for their accuracy. However, when they are available, they may help to provide safe care within the dental practice environment, contributing to a reduced risk of transmission for both patients and staff.
Appointment intervals may need to be lengthened to allow for any additional infection prevention and control arrangements, with appointment times staggered to minimise the waiting time for patients and help to maintain social distancing in the reception area.
Infection with COVID-19 is via three potential modes of transmission: contact, droplets and airborne particles.
Droplet transmission is due to contamination from infected droplets (>5 μm), including saliva, coming into contact with mucous membranes, such as the nose, mouth or conjunctiva. Such droplets are produced by coughing and sneezing and can travel significant distances. Protection is provided by social distancing (maintaining a distance of at least 2m) and wearing appropriate PPE. When droplets land on a surface they form fomites, which can then be transferred through contact with the contaminated surface. This is particularly important to bear in mind in the reception area, where compromised hand hygiene or inadequate social distancing can lead to contamination from surfaces such as door handles, desktops or chairs. Following local policies and national standards of infection control and prevention, both in the surgery and throughout the practice, is critical in safeguarding patients and staff. Within the dental surgery, airborne transmission is also a potential issue through the production of aerosols.
Section 3: During treatment
Aerosols may also be produced naturally during breathing, speaking, sneezing and coughing, and these must be acknowledged as a potential mode of transmission of COVID-19, via both droplet and aerosol transmission. All dental visits involve risk of exposure to aerosols and droplets, whether they occur naturally or are produced by mechanical interventions. This is primarily due to the close proximity of the staff member and patient over a reasonable period of time and it is therefore imperative that all staff take appropriate precautions in the use of the correct PPE.
Not all dental procedures create the same level of bio-aerosol, and therefore they do not have the same level of risk in terms of transmission. It is therefore important to acknowledge that a risk gradient exists, although in the absence of strong evidence it is difficult to quantify the risk.
A risk categorisation of dental procedures has been developed (see table 1, page 30 of the guidance for further details). It should not be considered a comprehensive list, but is simply included for illustrative purposes. It must also be stressed that all dental procedures are part of a risk continuum in terms of aerosol production, and the context of the procedure must be taken into consideration. This may include factors such as the length of the procedure, use of procedural mitigation, patient factors or potential risk to staff or patients. It may therefore be appropriate to recategorise certain procedures based on clinical judgement, experience and an appropriate risk assessment.
While the 3 in 1 syringe with combined air and water is categorised as high risk, when used very briefly, the amount of aerosol produced is likely to be considerably less than that produced by any other high-risk procedure. Consequently, if a risk assessment establishes that the combined 3 in 1 will only be used very briefly and no other high-risk procedures are planned, the precautions for low-risk procedures can be followed.
It is important to recognise that the R number or prevalence rate should not impact on the infection prevention protocols within the practice, nor the decision on whether to provide all dental care or not. Practices should be implementing universal precautions, with the assumption that all patients and staff are potentially infectious. The importance of the R number and prevalence rate may, however, have a significant impact on government recommendations on travel or social distancing. This must be considered when undertaking a risk assessment.
Procedural risk mitigation
High volume aspiration (HVA) has been shown to significantly reduce bio-aerosols and must be considered as a key mitigating measure in reducing aerosol spread.
High volume suction is considered to be the equivalent of greater than 250l/min and it is advisable to have this checked at regular intervals.
Fallow period after high aerosol-generated exposure (AGE) risk in a dental surgery
Clearance of infectious particles after an aerosol-generated procedure in dentistry usually depends on the ventilation and air change within the room. However, other factors, such as the type of procedure carried out, the use of HVA, the use of rubber dam, the duration of aerosol generation and the size and shape of the room, also have to be taken into account when deciding how long it will take for infectious viral particles to clear after a particular procedure. A Risk Stratification Matrix has been developed to assist practitioners in assessing the risks posed by AGE (see Section 3 of the guidance for further details).
Online Fallow Time Calculator
The FGDP has developed an online Fallow Time Calculator (FTC) to help dental health care workers calculate the amount of fallow time (or settle time) required after procedures.
The FTC allows practices to record important data on their fallow time calculations, providing information, justification and the ability to record the key data in the clinical records. The FTC tool will be updated as research improves our knowledge of how the production of dental aerosols is affected by mitigation factors.
After treatment, key points include:
- following standard decontamination procedures
- carrying out routine cleaning where the risk of AGE is low
- where the risk of AGE is high, doffing of gown, with mask retained and removed outside the surgery
- cleaning the floor at the end of each high-risk AGE or the end of each session
- ensuring no paper records are retained in the surgery while the risk of AGE is high or during the fallow period
- changing scrubs daily
- imposing a fallow time after higher-risk AGEs.
Air ventilation is important in providing a safe and comfortable workplace, and this is widely recognised within healthcare guidance and building control regulations. Adequate air ventilation is considered important in terms of general health and wellbeing. Current guidance recommends 10 air changes per hour for new buildings, including health treatment rooms.
The use of air ventilation as an environmental mitigation is based on the process of dilution of the aerosol by either introducing ‘fresh air from outside’ or by cleaning the existing air. Ventilation can be provided by natural or mechanical means and there are a variety of methods which can be considered to achieve dilution of the bioaerosol.
- Aerosol-generated procedures should not be conducted in a windowless room without mechanical ventilation or an air cleaner.
- Natural ventilation cannot be calculated reliably and needs to be discounted in relation to achieving a ‘reduced fallow time’ by use of environmental mitigation. This translates into 30 minutes fallow time for all procedures in a room that relies solely on natural ventilation with no procedural mitigation employed.
- FGDP/CGDent support the application of the SDCEP recommendations on mitigation-based reductions for fallow time.
- FGDP/CGDent support the use of mechanical ventilation to achieve at least 6 ACH to improve air quality and reduce fallow time.
- This guidance supports the use of air cleaners/scrubbers as an acceptable recirculation method of removing bioaerosol, and should therefore be considered an effective method of environmental mitigation, although their relative efficiency in terms of ACH must be taken into consideration.
Protecting vulnerable dental health care workers
Most people who get COVID-19 will be almost impossible to identify, and many of the patients who attend the surgery are potentially infective. This is why we need to take the appropriate precautions so that we can protect our patients, other members of the dental team and ourselves from COVID-19 infections. In the future, it is likely that rapid point of care testing will allow dental teams to conduct COVID-19 tests in the dental surgery to better understand the COVID-19 risks in patients as well as staff. Until then the recommendations are to use a combination of personalised risk assessments and universal precautions to protect staff.
Clinically extremely vulnerable people may include:
- solid organ transplant recipients
- people with specific cancers:
- people with cancer who are undergoing active chemotherapy
- people with lung cancer who are undergoing radical radiotherapy
- people with cancers of the blood or bone marrow such as leukaemia, lymphoma or myeloma who are at any stage of treatment
- people having immunotherapy or other continuing antibody treatments for cancer
- people having other targeted cancer treatments that can affect the immune system, such as protein kinase inhibitors or PARP inhibitors
- people who have had bone marrow or stem cell transplants in the last 6 months or who are still taking immunosuppression drugs
- people with severe respiratory conditions, including cystic fibrosis, severe asthma and severe chronic obstructive pulmonary disease (COPD)
- people with rare diseases that significantly increase the risk of infections (such as severe combined immunodeficiency (SCID), homozygous sickle cell)
- people on immunosuppression therapies sufficient to significantly increase risk of infection
- women who are pregnant with significant heart disease, congenital or acquired
- other people who have been classed as clinically extremely vulnerable, based on clinical judgement and an assessment of their needs. GPs and hospital clinicians have been provided with guidance to support these decisions.
Patients are at moderate risk of developing complications from coronavirus (COVID-19) where:
- they meet the criteria that make them eligible for the annual flu vaccination, except those aged 65 to 69 years old (inclusive) who have no other qualifying conditions, and
- they do not meet the Chief Medical Officer’s criteria for the high-risk group for COVID-19.
This includes the following patient groups:
- aged 70 or older (regardless of medical conditions)
- under 70 with one of the underlying health conditions listed below (for adults this is usually anyone instructed to get a flu jab as an adult each year on medical grounds):
- chronic (long-term) respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema or bronchitis
- chronic heart disease, such as heart failure
- chronic kidney disease
- chronic liver disease, such as hepatitis
- chronic neurological conditions, such as Parkinson’s disease, motor neurone disease, multiple sclerosis (MS), a learning disability or cerebral palsy diabetes
- those with a weakened immune system caused by a medical condition or medications such as steroid tablets or chemotherapy
- being seriously overweight (a BMI of 40 or above)
- those who are pregnant.
Although this article has only summarised the updates to the original article published in 1 June 2020, there has already been an update to it and this is the second update. For full and further details please see the full guidance. A link has been provided below.
- Fallow Time Calculator
- Implications of COVID-19 for the safe management of general dental practice: A practical guide. Version 2, College of General Dentistry/FGDP, 2 October 2020:
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