Effects of the Global Pandemic on indoor air quality in dental surgeries: Evaluating practical alternatives to current guidelines and regulations in Scotland.

The COVID-19 pandemic focused attention on the role of ventilation on improving indoor air quality to mitigate against the risk of spread of infection. The aim of this study was to evaluate the effectiveness of increased ventilation and explore an alternative solution for improving indoor air quality to mitigate the risk of airborne infection in dental surgeries. Dental surgeries present a specific risk of airborne infection due to the bio-aerosols generated by high-speed dental instruments such as drills and air-water syringes. Studies show that particulate matter, volatile organic compounds, and carbon dioxide levels often exceed recommended thresholds during dental procedures, contributing to poor indoor air quality and increased health risks. To mitigate these risks, regulatory bodies recommended increasing air changes per hour to 10-12 in dental surgeries. Implementing such systems poses significant physical, financial, and regulatory challenges, alongside ongoing high energy consumption costs. The study evaluated the rapid changes to the requirements and guidance to avoid the risk of airborne infections in dental surgeries during the COVID-19 pandemic. A prototype for an at-source aerosol extraction device was developed and tested in a live dental surgery using an air quality monitor to determine if it could effectively remove aerosols at-source. The prototype was an articulated hose with nozzle positioned close to the patient’s mouth and connected to the existing surgery suction pump, which aspirates fluid during dental procedures. Air quality was monitored in the dental surgery during similar aerosol-generating procedures with 10 air changes an hour and then using the aerosol extraction device. The test results indicated that this alternative strategy performed better than providing 10 air changes an hour with the average of particulate matter of 1µg, 2.5µg, 4µg and 10µg recording an average concentration of 0.19mg/m3 compared to 0.33mg/m3 when using 10 air changes per hour. These results demonstrate that an at-source extraction device could provide a viable alternative to high ventilation strategies. In conclusion, this study demonstrates that an at-source extraction device could mitigate against airborne infections in a cost-effective and energy efficient manner. Further testing, including larger sample size and computational fluid dynamics modelling, is needed to refine the design and assess its applicability across different dental settings. This research provides an opportunity for revising existing guidelines and explore alternative indoor air quality management solutions that ensure both practitioner and patient safety.