Removal and dispersal of biofluid films by powered medical devices: Modeling infectious agent spreading in dentistry
Ian Eames,
Francesco D'Aiuto,
Somayeh Shahreza,
Yousef Javanmardi,
Ramanarayanan Balachandran,
Martin Hyde,
Yuan-Ling Ng,
Kishor Gulabivala,
Sara Watson,
Hywel Davies,
Nicolas Szita,
Janette Khajeh,
Jeanie Suvan,
Emad Moeendarbary
Affiliations
Ian Eames
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK; Corresponding author
Francesco D'Aiuto
Unit of Periodontology, UCL Eastman Dental Institute, University College London, London, WC1X 8LT, UK; Corresponding author
Somayeh Shahreza
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Yousef Javanmardi
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Ramanarayanan Balachandran
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Martin Hyde
TSI, 30 Millbank, Westminster, London, SW1P 4WP, UK
Yuan-Ling Ng
Unit of Endodontology, UCL Eastman Dental Institute, University College London, London, WC1X 8LT, UK
Kishor Gulabivala
Unit of Endodontology, UCL Eastman Dental Institute, University College London, London, WC1X 8LT, UK
Sara Watson
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Hywel Davies
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Nicolas Szita
Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London WC1E 6BT, UK
Janette Khajeh
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
Jeanie Suvan
Unit of Periodontology, UCL Eastman Dental Institute, University College London, London, WC1X 8LT, UK; Corresponding author
Emad Moeendarbary
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Corresponding author
Summary: Medical procedures can disperse infectious agents and spread disease. Particularly, dental procedures may pose a high risk of disease transmission as they use high-powered instruments operating within the oral cavity that may contain infectious microbiota or viruses. Here we assess the ability of powered dental devices in removing the biofluid films and identified mechanical, hydrodynamic, and aerodynamic forces as the main underlying mechanisms of removal and dispersal processes. Our results indicate that potentially infectious agents can be removed and dispersed immediately after dental instrument engagement with the adherent biofluid film, while the degree of their dispersal is rapidly depleted owing to the removal of the source and dilution by the coolant water. We found that droplets created by high-speed drill interactions typically travel ballistically, while aerosol-laden air tends to flow as a current over surfaces. Our mechanistic investigation offers plausible routes for reducing the spread of infection during invasive medical procedures.