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Review 2: "Evaluating aerosol and splatter during orthodontic debonding: implications for the COVID-19 pandemic"

This paper studies aerosol and splatter deposition of fluorescein dye as a proxy for virus spread during an orthodontic debonding procedure. Dye was detected only in the proximity of the dental chair, and also suggests a low risk for aerosol generation.

Published onOct 08, 2020
Review 2: "Evaluating aerosol and splatter during orthodontic debonding: implications for the COVID-19 pandemic"
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key-enterThis Pub is a Review of
Evaluating aerosol and splatter during orthodontic debonding: implications for the COVID-19 pandemic

Introduction: Dental procedures often produce splatter and aerosol which have potential to spread pathogens such as SARS-CoV-2. Mixed guidance exists on the aerosol generating potential of orthodontic procedures. The aim of this study was to evaluate aerosol and/or splatter contamination during an orthodontic debonding procedure. Material and Methods: Fluorescein dye was introduced into the oral cavity of a mannequin. Orthodontic debonding was carried out in triplicate with filter papers placed in the immediate environment. Composite bonding cement was removed using a slow-speed handpiece with dental suction. A positive control condition included a high-speed air-turbine crown preparation. Samples were analysed using digital image analysis and spectrofluorometric analysis. Results: Contamination across the 8-metre experimental rig was 3% of the positive control on spectrofluorometric analysis and 0% on image analysis. There was contamination of the operator, assistant, and mannequin, representing 8%, 25%, and 28% of the positive control spectrofluorometric measurements, respectively. Discussion: Orthodontic debonding produces splatter within the immediate locality of the patient. Widespread aerosol generation was not observed. Conclusions: Orthodontic debonding procedures are low risk for aerosol generation, but localised splatter is likely. This highlights the importance of personal protective equipment for the operator, assistant, and patient.

RR:C19 Evidence Scale rating by reviewer:

  • Reliable. The main study claims are generally justified by its methods and data. The results and conclusions are likely to be similar to the hypothetical ideal study. There are some minor caveats or limitations, but they would/do not change the major claims of the study. The study provides sufficient strength of evidence on its own that its main claims should be considered actionable, with some room for future revision.



We read with great interest the article by Llandro et al.,1 which addresses a timely issue, and aims at assessing the impact of debonding procedures in orthodontics on aerosol production.

Why is the study  important?

The study provides further insight into aerosol production in dental practice. Indeed, the recent diffusion of SARS-CoV-2 and the high viability of the virus through aerosol particles have led to an increasing interest towards aerosol generating procedures, which should be limited when possible.2,3 Interestingly, the issue of aerosol production in orthodontics is addressed and appears relevant in the current scenario being orthodontic procedures extremely diffused worldwide especially among younger patients, which could potentially be asymptomatic.4

Lessons to be learned

Orthodontic procedures do not seem related to a massive aerosol production. Overall, it was reported that aerosol and spatter deposition was detected only in the proximity of the dental chair, suggesting a low risk for aerosol generation following orthodontic debonding. However, cautious practice of dental procedures should be further reinforced.

Potential issues with the study

The study was performed by using a slow speed handpiece with dental suction. It would be of interest to retrieve data on aerosol production in absence of containment measures, in order to establish a benchmark and to assess whether the procedures suggested are effective to limit aerosol production. Moreover, phantom studies have important limitations due to the simulation of the salivary flow and the low specificity on aerosol evaluation versus spatter. Overall, the study design appears more suitable in the assessment of larger spatter rather than the evaluation of micro-aerosol, which is of utmost importance in the current scenario as the presence of the SARS-CoV-2 has been reported in submillimeter aerosol particles.5

Further studies suggestion

Being the issue of aerosol extremely relevant, we encourage the performance of in-vivo assessment of aerosol production, possibly integrated by the characterization of the aerosol particles produced in terms of size. Such an evaluation may be performed with the support of air samplers or particle counting instruments, as suggested by the authors. Finally, the performance of microbiological sampling may complete the assessment of the impact of aerosol generating procedures on air quality.


We are grateful to the authors for raising the issue of aerosol production following debonding procedures in orthodontics. Assessing whether there is a risk of increased production of micro-aerosol may contribute to better delineating the impact of aerosol production in dentistry, and to give insights into the actual risk of cross-infection related to the dental procedures.


1.     Llandro H, Allison JR, Currie CC, Edwards DC, Bowes C, Durham J, Jakubovics N, Rostami N, Holliday R. Evaluating aerosol and splatter during orthodontic debonding: implications for the COVID-19 pandemic. 2020

2.     Chen J. Pathogenicity and transmissibility of 2019-nCoV-A quick overview and comparison with other emerging viruses. Microbes Infect. 2020;22(2):69-71. doi:10.1016/j.micinf.2020.01.004.

3.     Izzetti R, Nisi M, Gabriele M, Graziani F. COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy. J Dent Res. 2020 Aug;99(9):1030-1038. doi: 10.1177/0022034520920580. Epub 2020 Apr 17. PMID: 32302257.

4.     Rothe C, Schunk M, Sothmann P, Bretzel G, Froeschl G, Wallrauch C, et al. Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany. N Engl J Med. 2020;382(10):970-971. doi:10.1056/NEJMc2001468

5.     Liu Y, Ning Z, Chen Y, Guo M, Liu Y, Gali NK, et al. Aerodynamic characteristics and RNA concentration of SARS-CoV-2 aerosol in Wuhan Hospitals during COVID-19 outbreak. Nature 2020. doi: 10.1101/2020.03.08.982637.


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