The efficacy of an extraoral scavenging device on reducing aerosol particles ≤ 5 µm during dental aerosol-generating procedures: an exploratory pilot study in a university setting

Abstract

Objective/aim To identify small particle concentrations (eight categories: ≤0.1 µm × ≤5.0 µm) induced by aerosol-generating procedures (AGPs; high-speed tooth preparation, ultrasonic scaling; air polishing) under high-flow suction with a 16-mm intraoral cannula with and without an additional mobile extraoral scavenger (EOS) device during student training. Materials and methods Twenty tests were performed (16.94 m2 room without ventilation with constant temperature (26.7 (1.1) °C and humidity (56.53 (4.20)%)). Data were collected 2 min before, 2 min during, and 6 min after AGPs. The EOS device and the air sampler for particle counting were placed 0.35 m from the open mouth of a manikin head. The particle number concentration (PN, counts/m3) was measured to calculate ΔPN (ΔPN = [post-PN] − [pre-PN]). Results Mean ΔPN (SD) ranged between −8.65E+06 (2.86E+07) counts/m3 for 0.15 µm and 6.41E+04 (2.77E+05) counts/m3 for 1.0 µm particles. No significant differences were found among the AGP groups (p > 0.05) or between the AGP and control groups (p > 0.05). With an EOS device, lower ΔPN was detected for smaller particles by high-speed tooth preparation (0.1–0.3 µm; p < 0.001). Discussion A greater reduction in the number of smaller particles generated by the EOS device was found for high-speed tooth preparation. Low ΔPN by all AGPs demonstrated the efficacy of high-flow suction. Conclusions The additional use of an EOS device should be carefully considered when performing treatments, such as high-speed tooth preparation, that generate particularly small particles when more people are present and all other protective options have been exhausted.

Simulated and clinical aerosol spread in common periodontal aerosol-generating procedures

“…Instead, the present study used an HVS at the speed of 325 L/min and this is a real HVS according to current international guidelines. Furthermore, HVS reduced 82.6% and 93.8% of droplets and aerosol particles for ultrasonic scaler and air polisher, respectively, which supports the previous study that aerosols (≤ 5 μm particles) were reduced by HVS [ 17 ]. These findings support the view that using HVS during dental AGPs can dramatically reduce the spread of particles and thereby reduce the risk of occupational infection among dental healthcare workers.…”

Influence of flow rate and different size of suction cannulas on splatter contamination in dentistry: results of an exploratory study with a high-volume evacuation system

“…In addition to the efforts to improve the effectiveness of intra-/extraoral suction equipment [ 15 , 25 , 26 ], there is also an idea of reducing the amount of fluid spray during AGPs [ 27 ]. When HSP and ADP are used according to manufacture/our internal treatment guidelines, we measured lower water/powder fluid for ADP versus HSP—but that is not equivalent to the subjective sensation of the majority of the user and special equipment or techniques to control spray mist have been described [ 23 , 28 ].…”

“…Therefore, we do not claim to investigate the bioaerosol infection risk originating from those small droplets. Nevertheless, airborne droplets of all sizes can carry potentially pathogenic microorganisms like viruses and bacteria and several methods have been described for measuring aerosolization in dentistry, including air particle measurement [ 26 , 33 ], biological air sampling [ 34 ], the culturing of settle plates [ 35 ], and detection of fluorescent markers via indirect techniques with coloring the fluid [ 8 , 33 ]. We know that the use of fluorescent dyes cannot reveal the viability of any biological component, and as we did not measure the fluorescence intensity, only a quantitative analysis of the splatter and deposit distribution was possible.…”

“…In worst-case scenarios, there can be shown a slightly delayed aerosol particle distribution, e.g., on clinical extremities [ 3 ]. At least, the study was performed in a closed room without any air ventilation, so the accumulation of smaller droplets during AGPs could be assumed as higher than in a clinical situation with more movement of the examiner, assistants, or because of open windows or doors which well significant influence the distribution of smaller particles [ 26 , 33 ]. Although these limitations of our experimental study should be taken into account when trying to draw conclusions for “real” clinical dental treatment, however, the findings help to improve the current understanding of intraoral suction and provide highly reliable and reproducible data.…”

Normative Approaches for Oral Health: Standards, Specifications, and Guidelines

“…ISO 10637 (2018) specifies test methods and requirements for such equipment and distinguishes 3 classes based on the evacuation volume. There are indications that high-flow evacuation systems with around 300 L/min of air flow, such as class I of ISO 10637, significantly reduce spreading of droplet, splatter, and (potentially) aerosols into the dental environment (Graetz et al 2021). Standards for using saliva as a diagnostic tool are developed under ISO/WD/TS 5798 (2021) and ISO/FDIS 2 4307 (2021).…”