The efficacy of an extraoral scavenging device on reduction of splatter contamination during dental aerosol generating procedures: an exploratory study

Abstract

Introduction This study was conducted in light of the SARS-CoV-2 pandemic, which brought UK dentistry to a standstill. The market has seen a recent influx of unproven extraoral scavengers (EOSs), which claim to reduce the risk of particulate spread. Aims To investigate the efficacy of a commercially available EOS device on contamination reduction during dental aerosol generating procedures (AGPs). The secondary aim was to investigate differences between open and closed dental operatories. Method Dental procedures were simulated on a dental manikin using citric acid (10%) added to the water lines with universal indicating paper (UIP) placed in strategic locations in the operatory, on the clinician and assistant. Chromatic change related to settling of splatter containing citric acid on the UIP was analysed to calculate percentage intensity of splatter contamination. Results EOSs resulted in 20% reduction in frequency and 75% reduction in mean intensity of contamination of operatory sites. There was a 33% and 76% reduction in mean intensity contamination for clinician and assistant, respectively. Use of rubber dam and four-handed dentistry resulted in further reduction. Discussion This exploratory study demonstrates contamination by splatter in a simulated dental setting. The concern in dentistry regarding aerosol requires further quantitative investigation of smaller particles. Conclusions The routine use of four-handed dentistry and rubber dam should continue where possible to maximise risk mitigation during AGPs. However, on the basis of our findings, the use of an EOS device can further mitigate the magnitude and concentration of splatter.

Evaluating contaminated dental aerosol and splatter in an open plan clinic environment: Implications for the COVID-19 pandemic

“…Previous recommendations that bay partitions should have a height of 2 m above the patient are therefore likely to be unnecessary [ 9 ]. These findings are also in keeping with a recent study reporting splatter analysis from visual analysis of litmus paper when citric acid was added to the irrigation system [ 42 ]. The authors reported a similar distribution pattern of splatter up to 1.33 m. This study, however, only analysed splatter in single repetitions, and did not report the level of suction used.…”

“…We assessed the impact of two levels of dental suction within this study: medium volume suction (159 L/min air) and low volume suction (40 L/min air) as defined by current standards [ 43 ]. It is worth noting many previous studies using ‘high volume dental suction’ did not report their suction level [ 20 , 28 , 42 ] or used suction that fell below the 250 L/min criteria for high volume aspiration [ 31 ]. Reassuringly, we observed little difference in the reductions of close and distant contamination between low and medium suction, perhaps indicating that there is quite a low threshold for suction exerting substantial benefit.…”

Characterization and mitigation of aerosols and splatters from ultrasonic scalers

“…There is a serious deficiency in the literature regarding the risks posed by aerosols and splatter from aerosol-generating procedures (AGPs) in dental settings and the efficacy of various aerosol mitigation techniques. A number of studies have collected aerosols and splatters directly onto a collecting surface for subsequent analysis, which include fluorescent [13][14][15][16][17] or non-fluorescent [18][19][20] based chromatic indicators and microbiological methods using culture media [21][22][23][24] . These studies are limited by their inefficient collection of small size aerosols (<~50 µm) which do not provide a comprehensive characterization over the entire size spectrum.…”

Fallow time determination in dentistry using aerosol measurement

“…COVID-19 has the potential to spread during dental procedures through a number of routes. Attention has focused on the spread via droplets or ‘splatter’ that can either impact directly on the face of a susceptible person or, be deposited on a surface (Shahdad et al 2020; Allison et al 2021). However, there is increasing evidence that aerosols, particularly when highly concentrated in enclosed environments, may play an important role in disease transmission (WHO 2020; Li et al 2020; Miller et al 2020).…”

“…Other researchers have added dye or fluorescent marker to the water lines to examine the distribution of splatter and detect deposits as small as 1000 μm 2 in area, although this dimension exceeds what is typically classed as an aerosol (Chiramana et al 2013; Veena et al 2015; Shahdad et al 2020; Allison et al 2021). Small particles (≤16 – 27μm) deposited on microscope slides have also been studied, however, this did not account for aerosols that did not settle during the experiment (Junevicius et al 2005).…”