Ultrafine particles in scanning sprays: a standardized examination of five powders used for dental reconstruction

E Ochsmann,S Reich,T Kraus,P Brand

doi:10.1186/s12995-020-00271-2

Abstract

BackgroundIntraoral matting sprays for chairside systems can release fine or ultrafine particles or nanoparticles at dentists’ workplaces and cause work-related health problems by inhalation exposure. Until now, little is known about the magnitude of the ultrafine fraction, when using these scanning sprays. Hence, more information is needed for workplace risk assessments in dental practices.MethodsFive commonly used dental spray-powders were examined under standardized conditions. Ingredients were taken from the respective safety data sheet. Particle number-size distributions and total number concentrations were analyzed with a fast mobility particle sizer, and reported graphically as well as mean particle fractions smaller than 100 nm. Based on these measurements, risk assessments were conducted, and particle depositions in the lung were modelled.ResultsThe mean fraction of particles smaller than 100 nm varied between 9 and 93% depending on the matting agent and mode of application of the intraoral scanning spray. Propellants can represent a large fraction of these particles. Titanium dioxide, pigment-suspensions, talcum and others particles, which can pose relevant health risks, were listed as ingredients of scanning sprays in safety data sheets. Nevertheless, the deposited fraction of hazardous particles in the lung of employees in dental practices seems to be small (15%) during this dental procedure.ConclusionsOur results suggest that dentists’ personnel can be exposed to hazardous fine and ultrafine particles. Though extensive standardized measurements and systematic evaluation of safety data sheets were used for this study, they cannot sufficiently assess and categorize potential workplace-related health risks.

Highlights

Intraoral matting sprays for chairside systems can release fine or ultrafine particles or nanoparticles at dentists’ workplaces and cause work-related health problems by inhalation exposure
Instead this study focuses on the use of matting sprays in dental reconstruction and on the accompanied involuntary inhalation exposure of dentists to fine and ultrafine particles
Since the beginning of the twentyfirst century, coinciding with the ongoing development of CAD/CAM technology (CAD: computer-aided design; CAM: computer-aided manufacturing), the number of commercially available intraoral scanning systems has been continually increasing [4,5,6]. Accompanying this technical development was the development of different scanning sprays for the respective chairside system

Summary

Introduction

Intraoral matting sprays for chairside systems can release fine or ultrafine particles or nanoparticles at dentists’ workplaces and cause work-related health problems by inhalation exposure. Since the beginning of the twentyfirst century, coinciding with the ongoing development of CAD/CAM technology (CAD: computer-aided design; CAM: computer-aided manufacturing), the number of commercially available intraoral scanning systems has been continually increasing [4,5,6] Accompanying this technical development was the development of different scanning sprays for the respective chairside system. Not initially classified as a nanotechnologybased products, the matting sprays in use can contain airborne ultrafine fractions [9], and the process of coating the teeths’ surfaces with a matting agent before taking the optical impression, represent a means of exposure to fine and ultrafine particles in dentists, dental personnel and patients [9]

Methods

Results

Conclusion