Virologists and dental associations are in agreement: very small infectious particles (so-called aerosols with a size of approx. 0.3 – 0.4 μm) present in indoor air are one of the main causes for the rapid spread of the coronavirus. In his recommendations for dealing with the corona pandemic in schools or comparable institutions, Prof. Dr. med. Dieter Köhler writes: “Corona viruses are mainly transmitted via respiration; coughing and sneezing are less significant as compared to bacterial infections”.
While viral aerosol clouds in the open air are immediately blown away or diluted due to air movement, the aerosol concentration in closed rooms increases via exhaled particles with each outward breath. Therefore, the German Dental Association also advises that for reasons of preventive health protection, the formation and spread of aerosols should be avoided, as these fine dust clouds of bacteria and viruses from a size of < 5 µm can penetrate into the pulmonary alveoli. However, if one looks at the hygiene guidelines of the German Working Group for Hygiene in Dentistry, doubts arise as to whether the measures recommended for protection are sufficient. The danger of aerosols should be countered by antiseptic rinsing and suitable protective clothing. The non-contamination of surfaces and treatment equipment is described in detail. However, it does not describe how doctor, patient and dental team can protect themselves against the inhalation of infectious aerosols. There are even recommendations in the press that a ventilator would supposedly protect against the inhalation of infectious aerosols. This is attributed to a comment made by virologist Christian Droste, who in one particular statement recommended that ventilators should be positioned in front of open windows. This would blow the infectious aerosol clouds out of the room into the open air. In theory, this recommendation is accurate. In practice, however, a window that is open around the clock is not practical. Neither in winter nor during patient treatment. Worse still, a ventilator does not dilute aerosol clouds with fresh air when the window is closed, but spreads them into the farthest corner of the room. In this case, a ventilator or air conditioning system can even increase the risk of infection. Effective and infection-preventive solutions are nevertheless available.
Airlines are leading the way: Air purifiers in airplanes protect against infection
If the room air is permanently filtered with a high air exchange rate, the risk of infection from aerosols released when speaking or coughing is reduced to almost zero. Even a minimum distance of 1.5 to 2.0 metres is no longer necessary with permanent room air filtration because pathogens in the recirculated air are literally “nipped in the bud” by the use of a special HEPA filter. This air filtration technology has long been used in the air industry, e.g. in Lufthansa planes. Air-conditioning systems equipped with a particulate HEPA filter are designed to filter the cabin air as effectively as is otherwise only the case in hospitals. Furthermore, vertical ventilation, which runs from the ceiling to the floor, further reduces the risk of infection. There is accordingly no need for airlines and their advocate IATA (International Air Transport Association) to leave the middle seat empty in airplanes.
A comparably effective solution for dental surgeries is the mobile air purifier TAC V+
While In the dentist’s chair, you’re exposed to close contact, which generally facilitates virus transmission. The treatment is carried out at eye level and aerosols emitted during breathing and speaking are inhaled directly by the person opposite. Such an aerosol cloud contains dust as well as viruses and bacteria. These fine dust clouds serve as a means of transport for the pathogens into the body. A new type of air purification technology from Heinsberg promises a remedy. With the TAC V+ air purifier for dental surgeries, Trotec, a leading company in the production of air filtration technology has developed a mobile air purifier that produces a volume of clean air per person several times higher than the air filtration systems used in aviation. The air in the treatment area is circulated and cleaned by the TAC V+ with similarly high air exchange rates as is otherwise only the case in hygiene-sensitive clean room environments and operating rooms. This is made possible on the one hand by the high air output of the air purifier, which is absolutely necessary to remove floating aerosols from the treatment room and areas close to the floor as quickly as possible. On the other, a new type of HEPA high performance filter of filter class H14 and with a filter efficiency of 99.995 % ensures that airborne bacteria and viruses do not re-enter the room air during the air exchange.
What sounds very technical in theory, proves to be extremely uncomplicated in practice. The air in the treatment area is drawn in close to the floor, freed from bacteria and viruses by the special H14 HEPA filter and then released into the room draught-free in the form of clean air without germs. Simply put: The treatment area becomes a clean room and infectious aerosols are extracted and filtered immediately after release. The suction system in the oral cavity protects against the large and sometimes infectious droplets. The air purifier TAC V+ removes the tiny aerosols – before they are inhaled.
Due to its mobile and compact design, the TAC V+ can be placed almost anywhere. In the direct vicinity of the treatment unit, but also in the waiting area, at reception or in the practice’s own laboratory. No installation or complicated connections necessary. Simply plug it in and the air purifier instantly provides the maximum possible protection against infection.
Is the air filtration technology used in aviation comparable to a mobile air purifier?
“The answer is yes. The technology may be different, but the results are comparable!”, according to Joachim Ludwig, Technical Managing Director of Trotec GmbH. “The performance data of our TAC V+ even surpasses the clean air performance (per person and area present) used in aircraft and provides even greater protection for medical staff and patients in medical practices”.
Effective protection against airborne viruses is contingent on three decisive factors:
- A high air exchange rate. The air exchange rate refers to the number of times the air gets replaced in each room every hour. Or to put it another way: How quickly infectious viruses are filtered from the air before they are inhaled by someone. Airplanes typically filter cabin air with an air exchange rate of 20 times per hour. This means cabin air is circulated and cleaned once every 3 minutes. The TAC V+ air purifier produces a similar air exchange rate, however with a notably higher volume of clean air per person than in an airplane.
- The volume of clean air per person is the second decisive factor: Effective filtering of air throughout an entire room is not the only important process. Aerosol clouds that often form spontaneously need to be diluted within a matter of seconds, as a key factor behind infections is the viral load inhaled by humans when breathing. No filtration system is capable of filtering virus clouds as soon as they occur. Even in airplanes. The “first-aid” response in this instance is diluting the infectious aerosol clouds as quickly as possible through a high volume of clean air. If possible, immediately after exhalation. The high volume of clean air produced by TAC V+ enables quick dilution of aerosol clouds and complete filtration within minutes. The right combination of air exchange rate and high clean air volume reduces the risk of infection by aerosols in the treatment area to almost zero.
- Maximum filter efficiency: The H14 HEPA filter used in TAC V+ filters 10 times better than conventional H13 filters. This enables the permanent removal of 99.995% of all airborne bacteria and viruses from air in the room. The germs are separated in the HEPA filter and the device automatically decontaminates itself after a preset time. This technology, developed and trademarked by Trotec, is currently the only technology of the sort in the world.
Virus-free breathing air is an indispensable component of any set of hygiene measures
Social distancing rules are not to be observed during treatment. Visors and medical mouth-nose masks only protect against larger droplets, but not against aerosol particles in the micrometer size range, which also spread like smoke in the room and only sink to the ground slowly and over a wide area after several hours. Full protection is only provided by regular air filtration, which also minimises the risk of aerogenic infection. The only current solution in the required performance class is the mobile TAC V+. The air purifier TAC V+ does not simply transfer infection protection from the aircraft to the practice. It offers an additional protection for doctor, medical staff and patient.
Prophylaxis for doctor, practice team and patients
Take precautions! What applies to dental prophylaxis should also be applied to protection for patient, employee and oneself.
You cannot ask for more protection, and you shouldn’t settle for any less for your employees and patients:
- Compliance with all requirements and hygiene regulations (non-contamination, protective equipment and visors, spit protection walls at the reception, disinfection measures, etc.)
- Air purifiers to reduce the aerogenic risk of infection via the air
Interesting facts about the H14-HEPA high performance filter with a transmittance of ≤ 0.005%
Thanks to their first-class filter efficiency and innovative performance characteristics, the H14 virus filters specially developed by Trotec for the TAC V+ and TES 200 air purifiers are quite impressive. With a transmission level of only 0.005% and a separation efficiency of 99.995%, they offer 10 times the separation efficiency of conventional H13 filters. Thanks to these first-class properties, H14 high-performance filters are even used for clean air production in operating theatres and in other comparably hygiene-sensitive areas. The greatest possible safety, therefore, to protect employees in dental surgeries from the dangers of infection
All H14 high-performance filters offered by Trotec meet the highest quality standards, which are obligatory for the filtration of bacteria and viruses:
- Each H14 high-performance filter is individually tested and given its own serial number.
- The test report is enclosed with each H14 filter in duplicate as a certificate.
- The original test certificate can be filed away and a copy attached to the air purification device when required.
- H14-HEPA high performance filters are tested according to EN 1822 and EN 60335-2-69.
The TAC V+, now available for purchase or rental, was developed and tested in a Heinsberg-based study. The device is available in various colours for £3,797.04 in the Trotec Shop.
Further information:
Trotec GmbH, Mr Jochem Weingartz
Telephone: +49 2452 962-137
