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Covid response

Air quality in dental surgeries

Ensuring a safe environment

Dental treatment involves a range of equipment and 'aerosol generating procedures' which can produce significant amounts of saliva/water-based aerosols in the micron and sub-micron range which present a potential transmission risk for the Covid-19 virus. There have been limited studies into the amount, size range and distance spread of dental aerosols. As dentists in England resume a more normal service the current guidance is to introduce a minimum of one hour ‘fallow time’ between patients to allow the aerosol particles to dissipate.

During lockdown the number of dental procedures was drastically reduced, resulting in an increase in the proportion of extractions and the number of prescriptions for antibiotics. Dental practices are now struggling to meet demand, and the fallow time between patients reduces the number of appointments each day. In addition, the cost of PPE for treating every patient has now increased significantly. There is now an urgent need to improve national dental health and help make dental practices financially viable.

Mydentist, part of the IDH group, is the largest dental provider in Europe and had been in discussions with NPL before the Covid-19 situation about ventilation in dental surgeries. However, in preparation for reopening dental practices for routine treatments, discussions focused on ensuring the safety of clinics for both practitioners and patients. Mydentist asked NPL to perform measurements in a working dental surgery to detect and measure the aerosols produced by a variety of dental procedures and record how they changed over time. NPL used a laboratory optical particle counter instrument to take measurements and compare them with the background levels.

This feasibility study indicated that there was little or no detectable increase in the concentration of aerosol particles for the majority of the ‘aerosol generating procedures’ carried out by dentists. Aerosols were being effectively captured and reduced by the use of good practice mitigation techniques, such as the high-volume suction tool and rubber 'dams'. This information, along with findings from Newcastle University, was presented to the Scottish Dental Clinical Effectiveness Programme (SDCEP) and will help them make recommendations on fallow times and aerosol mitigation procedures.

NPL are planning a more detailed study, taking measurements in a range of dental surgery environments, with varying ventilation levels, instrument types,  and for different procedures and mitigations, in order to provide definitive advice. All of the information from these tests will be shared widely across the dental profession and dental research community.  

NPL has also been working with makers of UVC lamps to understand their role in enhancing sterilisation during the fallow time.

If you would like to discuss further, please contact us.

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Impact during Covid-19

  • Collecting data to establish safe operational procedures
  • Facilitating the resumption of dental services to meet demand
  • Helping dentists to return to safe and commercially viable operation  
  • Applying air quality monitoring knowledge and experience to dental environment 

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