The main transmission path of SARS-CoV-2 is through droplet infection.¹ Recent studies indicate that transmission via aerosols in normal social settings cannot be excluded. However, a final consensus does not seem possible at this stage.² Aerosols differ from droplets and spray mist. Owing to their smaller particle size (<50 μm), they can be carried several metres away and can be detected in the room air for up to 30 minutes.³

How can the contamination of dental aerosols be reduced?

It is well documented that the use of a preprocedural mouthrinse with a chlorhexidine solution for 30–60 seconds reduces the bacterial load in aerosols by up to 70%.^4,5,6 However, chlorhexidine shows low effectiveness against coronaviruses.^7,8 Hydrogen peroxide at a concentration of 0.5% or more has been proved to effectively kill viruses.^9,10 EMS has collaborated with experts from the fields of dentistry and chemistry to develop a mouthrinse solution, ViruProX. This new solution contains hydrogen peroxide (1.5%) and cetylpyridinium chloride (0.05%), which efficiently kill viruses in addition to bacteria. We recommend that patients gargle and rinse with ViruProX for 60 seconds at the beginning of each treatment. This process should be repeated, if possible, after 30 minutes.

The correct use of mouth–nose protection masks, goggles and face shields, as well as the efficient and safe sterilisation of instruments, is mandatory. AIRFLOW and PIEZON handpieces and all instruments should be sterilised after each treatment. The surface disinfection and regular rinsing of the suction system are further obligatory measures. Good ventilation of the treatment rooms after each patient is strongly recommended.¹¹

How can the formation of aerosols be reduced?

Nearly all dental instruments used in common treatments generate aerosols: low- and high-speed handpieces, turbines, sonic and ultrasonic devices, air/water syringes, and air polishing devices.¹² The use of a high-vacuum suction system with a suction volume of at least 300 l/min, in combination with an optimal saliva ejector, can effectively reduce aerosol formation.^12,13 Four-handed dentistry allows optimal suction.¹⁴ When working two-handed for professional mechanical biofilm removal, a skilled suction technique in combination with an OptraGate (Ivoclar Vivadent) supports the reduction of aerosols very well.

Further information and recommendations are included in the clinical review titled “COVID-19 transmission in dental practice: Brief review of preventive measures in Italy” by Prof. Filippo Graziani of the University of Pisa, who is the former president of the European Federation of Periodontology and the Italian Society of Periodontology and Implantology. Furthermore, the Bavarian State Chamber of Dentists and the Association of Statutory Health Insurance Dentists of Bavaria have addressed patients with reassuring words in their letter “Dental treatments: No increased risk in dental practices despite COVID-19”.

Editorial note: A list of references is available from the publisher.

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