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Waterline Disinfectants Reduce Dental Bioaerosols: A Multitracer Validation

Lookup NU author(s): James AllisonORCiD, Christopher Dowson, Professor Nicholas JakubovicsORCiD, Dr Christopher NileORCiD, Professor Justin DurhamORCiD, Dr Richard HollidayORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Oral microbes are dispersed during dental treatment and reduction methods have been proposed, but Dental Unit Waterline (DUWL) disinfectants have received little attention; specifically, the effect on viruses has not been studied. This study aims to: (i) investigate the effect of DUWL disinfectants on viral dispersion in dental bioaerosols (ii) establish a dual tracer system using live bacteriophage and fluorescein supported by optical particle measurement. Bacteriophage MS2 was used as a viral tracer, and fluorescein as a fluorescent tracer. Validation experiments were conducted to exclude interference of one tracer with the other, or of DUWL disinfectants on detection methods. Simulated “saliva” containing the tracers was infused into the mouth of a dental mannequin during ten-minute dental procedures with an air turbine handpiece (n = 3 replicates). Aerosols and droplets were sampled in an enclosed dental operatory using air samplers and settlement onto sterile filter papers. Bacteriophage was quantified using plaque assays and Reverse Transcriptase quantitative Polymerase Chain Reaction (RT-qPCR). Fluorescein was quantified fluorometrically. The effect of DUWL disinfectants on aerosol concentration was assessed in separate experiments using an Optical Particle Counter (OPC). DUWL disinfectants reduced bacteriophage viability, and interference between tracers was not observed. In simulated clinical procedures, the disinfectant ICX® reduced bacteriophage detection substantially (p < 0.001; two-way ANOVA). MS2 RNA was detected in all experimental samples but not negative controls. Samples positive on RT-qPCR but not plaque assays may indicate that virions at distant sites are non-viable. Fluorescein tracer showed good agreement with the bacteriophage tracer. DUWL disinfectants designed for continuous presence in irrigants reduce the dispersion of viable virus in dental bioaerosols during simulated procedures. Their use may therefore be important for routine infection control, and as a mitigation factor during infectious disease outbreaks. Future studies should explore this using a range of viruses and other microbes.

Publication metadata

Author(s): Allison JR, Dowson C, Jakubovics NS, Nile C, Durham J, Holliday R

Publication type: Article

Publication status: Published

Journal: Journal of Dental Research

Year: 2022

Volume: 101

Issue: 10

Pages: 1198-1204

Print publication date: 01/09/2022

Online publication date: 01/05/2022

Acceptance date: 25/03/2022

Date deposited: 25/03/2022

ISSN (print): 0022-0345

ISSN (electronic): 1544-0591

Publisher: Sage Publications


DOI: 10.1177/00220345221093522


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Funder referenceFunder name
Faculty of Dental Surgery, Royal College of Surgeons of England
Wellcome Trust