Graphic Simulation of SARS-CoV-2 Droplets: Why Respirators should be used in Dental Healthcare Settings? ZC31-ZC35
Fàbio Barbosa Souza,
Av. Prof. Moraes Rego s/n, Cidade Universitària, Recife, Pernambuco, Brazil.
Introduction: Knowledge about the morphological characteristics of facial masks/respirators and their relationship with the possibility of interaction with respiratory droplets in the COVID-19 pandemic is fundamental in dental healthcare settings.
Aim: This study evaluated interfibrillar gaps of cloth mask, surgical mask and Filtering Face Piece 2 respirator through Scanning Electron Microscopy (SEM) in order to perform a graphic simulation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) respiratory droplets in the gaps among mask fibres.
Materials and Methods: A fragment (1 cm2) of the cloth mask were used to perform a SEM analysis. The distance among fibres was determined by Energy Dispersive Spectrometry (EDS). Graphic simulation of droplets with different sizes (0.5 μm; 5.7 μm; 12 μm) was performed by an image editing program (Adobe Illustrator).
Results: The image analysis showed that average distance among the fibres was 67.91 μm (cloth mask), 11.72 μm (surgical mask), 11.97 μm (respirator FFP2). Superimposition of masks layers resulted in no gaps between FFP2 fibres. Surgical mask exhibited openings between fibres in 1.43% of the studied total area. The cloth mask showed large gaps, in which it would be possible to transpose more than 680 million droplets (5.75 μm).
Conclusion: FFP2 respirator showed no spaces among fibres after superimposition of structural layers, which would promote the blockage of the graphic simulation of SARS-CoV-2 droplets.