A clinical observational analysis of aerosol emissions from dental procedures.

Aerosol generating procedures (AGPs) are defined as any procedure releasing airborne particles <5 µm in size from the respiratory tract. There remains uncertainty about which dental procedures constitute AGPs. We quantified the aerosol number concentration generated during a range of periodontal, oral surgery and orthodontic procedures using an aerodynamic particle sizer, which measures aerosol number concentrations and size distribution across the 0.5-20 µm diameter size range. Measurements were conducted in an environment with a sufficiently low background to detect a patient's cough, enabling confident identification of aerosol. Phantom head control experiments for each procedure were performed under the same conditions as a comparison. Where aerosol was detected during a patient procedure, we assessed whether the size distribution could be explained by the non-salivary contaminated instrument source in the respective phantom head control procedure using a two-sided unpaired t-test (comparing the mode widths (log(σ)) and peak positions (DP,C)). The aerosol size distribution provided a robust fingerprint of aerosol emission from a source. 41 patients underwent fifteen different dental procedures. For nine procedures, no aerosol was detected above background. Where aerosol was detected, the percentage of procedure time that aerosol was observed above background ranged from 12.7% for ultrasonic scaling, to 42.9% for 3-in-1 air + water syringe. For ultrasonic scaling, 3-in-1 syringe use and surgical drilling, the aerosol size distribution matched the non-salivary contaminated instrument source, with no unexplained aerosol. High and slow speed drilling produced aerosol from patient procedures with different size distributions to those measured from the phantom head controls (mode widths log(σ)) and peaks (DP,C, p< 0.002) and, therefore, may pose a greater risk of salivary contamination. This study provides evidence for sources of aerosol generation during common dental procedures, enabling more informed evaluation of risk and appropriate mitigation strategies.

Patient reported experiences and treatment outcomes of orthodontic patients treated within secondary care settings in the South West of England during the COVID-19 pandemic.

OBJECTIVE: To assess the impact of the temporary cessation of orthodontic services on patients undergoing treatment during the COVID-19 pandemic. DESIGN: Two-phase multicentre service evaluation. SETTING: Secondary care orthodontic departments in the South West of England. MATERIALS AND METHODS: Phase 1 - Patient-Reported Experience Measure questionnaire (PREM). The questionnaire was distributed to patients who had undergone orthodontic treatment during the COVID-19 pandemic once services had resumed. Phase 2 - assessment of treatment outcomes, specifically with the Peer Assessment Rating (PAR) Index. A total of 280 PAR scores were obtained from a cohort of patients treated before and during the pandemic. RESULTS: A total of 711 PREM questionnaires were completed. Participants generally felt relaxed when visiting secondary care settings, orthodontic departments and whilst wearing orthodontic appliances during the pandemic. Nearly 40% of participants were concerned that the pandemic would impact on their treatment, particularly treatment length. Treatment outcomes revealed that patients treated before and during the pandemic experienced percentage PAR score reductions of 83.9% and 80.6%, respectively. Patients receiving treatment during the pandemic experienced longer treatment durations of 126 days. CONCLUSION: During the pandemic, low levels of anxiety were reported with respect to receiving orthodontic treatment in secondary care settings. Irrespective of the pandemic, a high standard of orthodontic treatment was provided. However, patient concerns regarding treatment length were justified.