300 is a must
Pilot study: Aerosol reduction by means of an intraoral spray mist suction
High-volume suction with a large cannula – the way to deliver the necessary safety and reliability
Based on the current state of scientific knowledge, there is uncertainty over the degree to which SARS-CoV-2 viruses can be transmitted via dental aerosols. By contrast, latest research results obtained as part of an in vitro pilot study from DÜRR DENTAL do indeed offer certainty in relation to the suction of aerosols. These results show that, with effective suction in the mouth of the patient at a rate of around 300 l/min, all dental treatments can be carried out and all the normal equipment can be used. These results have now also been confirmed by the S1 guide "Handling dental patients under a burden of aerosol-transmissible pathogens". The in vitro pilot study draws clear conclusions about both the underlying theoretical principles (catchphrase: "it's all about the flow rate") and the implications for dental practices (catchphrase: "high-volume suction at a rate of 300 litres per minute with a large cannula"). Based on this pilot study, clinical follow-up studies are currently being planned in order to obtain further well-founded results on all aspects of avoiding dental aerosols.
S1 guide underlines results
These results have been underlined very recently by the updated S1 guide "Handling dental patients under a burden of aerosol-transmissible pathogens" published in March 2021:
Provided the measures recommended in dental medicine for the use of water-cooled instruments are met, which include […] and high-volume suction at a rate of around 300 l/minute using a suction canula with a diameter of at least 10 mm, protection for the treatment team and the patient against droplets and aerosols is ensured by a combination of specific prevention measures […]. As long as this is ensured, there is at present no solid evidence in support of additional equipment for suction.
Aerosol prevention depending on the flow rate at the cannula
*The S-curve shown was graphically (not mathematically) laid through the measuring points to ensure a better visibility of the result. Measurement results from internal study, September 2020, Dürr Dental
*The S1 guide "Umgang mit zahnmedizinischen Patienten bei Belastung mit Aerosolübertragbaren Erregern (S1) Langfassung 2021" is available to download from www.dgzmk.de/aerosol-uebertragbare-erreger. (at the moment only available in german language
1 The S1 guide is published by DGZMK, Deutsche Gesellschaft für Zahn-, Mund- und Kieferheilkunde (German Society of Dentistry and Oral Medicine)