Aerosol Reduction of 2 Dental Extraoral Scavenger Devices In Vitro.

OBJECTIVE: Since the outbreak of SARS-CoV-2, aerosol control in the operatory has become a key safety issue in dentistry. The utilisation of extraoral scavenger devices (EOSs) is one of the various approaches to in-treatment aerosol reduction in dentistry. The use and efficacy of EOSs in dental settings, however, are still a matter of debate in the literature and there are still open questions about their proper use. Thus, research into this area is essential to inform dental practice. The objective of this study was to examine the aerosol reduction efficacy of two different EOS in vitro. METHODS: Two commercially available EOSs were tested during modeled dental treatment in a setup that previously proved to generate high aerosol load. Measurements were done in two particle size ranges: 5.6-560 nm (the full range of the spectrometer) and 60.4-392.4 nm (a range that is especially relevant to the spread of SARS-CoV-2 with aerosol). RESULTS: Both devices managed to reduce the aerosol load to a statistically significant extent as compared to the scenario when only a high-volume evacuator and a saliva ejector (and no EOS) were used. CONCLUSIONS: Within the limitations of the study, the results support the assumption that EOSs for aerosol reduction increase in-treatment safety in the dental operatory.

Aerosol generation and control in the dental operatory: An in vitro spectrometric study of typical clinical setups.

Dental turbines and scalers, used every day in dental operatories, feature built-in water spray that generates considerable amounts of water aerosol. The problem is that it is not exactly known how much. Since the outbreak of COVID-19, several aerosol safety recommendations have been issued-based on little empirical evidence, as almost no data are available on the exact aerosol concentrations generated during dental treatment. Similarly, little is known about the differences in the efficacy of different commercially available aerosol control systems to reduce in-treatment aerosol load. In this in vitro study, we used spectrometry to explore these questions. The time-dependent effect of conventional airing on aerosol concentrations was also studied. Everyday patient treatment situations were modeled. The test setups were defined by the applied instrument and its spray direction (high-speed turbine with direct/indirect airspray or ultrasonic scaler with indirect airspray) and the applied aerosol control system (the conventional high-volume evacuator or a lately introduced aerosol exhaustor). Two parameters were analyzed: total number concentration in the entire measurement range of the spectrometer and total number concentration within the 60 to 384 nm range. The results suggest that instrument type and spray direction significantly influence the resulting aerosol concentrations. Aerosol generation by the ultrasonic scaler is easily controlled. As for the high-speed turbine, the efficiency of control might depend on how exactly the instrument is used during a treatment. The results suggest that scenarios where the airspray is frequently directed toward the air of the operatory are the most difficult to control. The tested control systems did not differ in their efficiency, but the study could not provide conclusive results in this respect. With conventional airing through windows with a standard fan, a safety airing period of at least 15 minutes between treatments is recommended.