Are Non-woven Gowns Safe for Dental Professionals? A Preclinical Double-Blind Study

Abstract

With the advent of the coronavirus disease 2019 (COVID-19) pandemic, the risk of dental professional's infection increases exponentially due to aerosol-generating procedures. The protective performance of dental professional gown fabrics is a major challenge against microorganisms and aerosols. Globally, health care workers wear gowns manufactured with non-woven fabrics. However, these professionals may have a false greater sense of protection based on the greater weight of the gown's fabric. This study evaluated whether aerosol generated by dental procedures has the potential to pass through three different non-woven weights (40, 60, and 80 g/m2). Single and folded formats of each weight were analyzed. The positions of the mannequin and the high-speed handpiece were standardized. The non-woven samples were placed over a sheet of sulfite paper and fixed on a marked position of a standardized smooth surface, 10 cm away from the end of the mannequin's head, simulating the dental professional body. For better visualization, the water used in the equipment was tinted with water-soluble red artificial dye. Blind to the nature of the groups, one researcher started the 5 uninterrupted min of aerosol production. The sheets were randomized coded, so that the samples could not be identified by the evaluator. Another researcher, blind to the tests, scanned all sheets and the images were analyzed by ImageJ software. The groups showed significant differences (p < 0.01). Except for the folded 80 g/m2, all groups presented pigmented mean areas ranging from 16.18% (60 g/m2 folded) to 35.68% (40 g/m2 single), suggesting that the one-layer non-woven samples were not effective as barriers for 5 uninterrupted min of aerosol spray. Dental procedures exceeding the studied time may provide different results with the non-woven 80 g/m2 folded. Dental health workers, who are exposed daily to aerosol-generating procedures, should be aware of the exact specification and performance of the fabrics used in the manufacturing of their disposable garments. If the use of an impermeable surgical gown is not possible during aerosol-generating procedures, a plastic garment associated with a disposable gown should be worn, as recommended by the World Health Organization.