Interview: Corona terminator protects dental staff and patients from SARS-CoV-2
In the absence of a dental market response to the SARS-CoV-2 pandemic, Dr Mustafa Ayna, a Germany-based dentist who heads his own practice in Duisburg, decided to take action and designed a device that eliminates the SARS-CoV-2 virus before it can spread in the treatment room. In cooperation with mechanical engineer Philipp Maack from the Ruhr University Bochum and Dr Aydin Gülses of the clinic for oral and maxillofacial surgery at the University Hospital Schleswig-Holstein in Kiel in Germany, he designed the corona terminator. He hopes that the device will soon be available for other dental practices.
Dr Ayna, thank you for speaking with us. How did you come to develop the corona terminator?
Shortly before the lockdown in Germany, there was a great need for information and a high level of insecurity among the medical and dental community with regard to aerosols and how they spread. Many dentists felt let down. From my research on aerosols, I was aware that they can stay within a radius of up to 2 m from where they are generated. However, I couldn’t find any product on the dental market that would have worked as a solution. Therefore, during the lockdown, I started to research something that I could build myself.
How exactly does the device work?
It is a disinfection device, an extra-oral aspiration unit that aspirates bioaerosols from the patient’s mouth. We know from other studies that about 40–50% of aerosols can be removed with conventional aspiration mechanisms. I wanted to find a solution that would allow capture and elimination of the rest too, so that the SARS-CoV-2 virus would not stay in the treatment room for hours.
The aspiration unit consists of a suction tube and a UV unit. This is a 3D-printed element with UV tubes (fluorescent units) that immediately disinfects the air passing through it, killing bacteria and viruses. In addition, I have added a safety mechanism. If viruses should survive, they are caught by a HEPA filter (Class 14).
How did you measure the efficiency of the device? Do you plan to publish a study on it?
We are in the process of measuring the efficiency. However, coronaviruses cannot be handled in a dental practice. You would need an S3 test laboratory [laboratory with a specified biosecurity level] to perform testing, and there are not that many of those laboratories in Germany available. Nevertheless, a lot of information is already well documented and we know how much aerosol is produced during a treatment. From other studies, we also know how sensitive coronaviruses are to UV light and that HEPA filters (Class 14) trap aerosols containing viruses. Considering how powerful the engine is, we have calculated how many cubic litres the machine must suck and how long the air must remain in the UV unit to kill the virus. According to these criteria, we adjusted the strength of the unit, and just to be on the safe side, added some additional power.
A study is also in planning. However, in light of the knowledge lacking on SARS-CoV-2, one cannot necessarily wait for study results, especially as a dentist is exposed to a very high risk of the virus. Alone, I do not have the resources that might be available at a university. I think the invention does not necessarily have to be tested as long as I stick to scientific standards. Having said that, in my practice, we still wear masks and visors in order to get the maximum protection.
Since when have you been using the device, and how exactly is it applied in your practice?
Shortly before the lockdown in mid-March, I procured the materials, and during the lockdown, I constructed the device. I have been using it permanently in my practice since the middle to end of March. Thus, I was able to perform surgical procedures on patients during this time.
As soon as we start a treatment, for example when using a turbine or calculus removal equipment, or when a professional tooth cleaning is performed, we switch the device on. This is because, according to studies, the SARS-CoV-2 virus can remain in the air in suspended particles for 2–3 hours. Depending on the size of the room, it can be disinfected in 5–10 minutes.
“Because of the corona terminator, my employees are calmer and the situation in my practice is generally more relaxed”
How has the corona terminator affected your everyday practice? How have your patients and staff reacted to the device?
I’ve noticed a great difference to other practices, which are scheduling few appointments at the moment, whereas I am working at 95% capacity. Compared with the same time last year, I’ve hardly seen any drop in turnover or reduced treatment scheduling, except right at the beginning of the lockdown. Many patients have called and asked what additional precautions my practice is taking. We communicated very well, and the corona terminator quickly became known among our patients.
Because of the corona terminator, my employees are calmer and the situation in my practice is generally more relaxed. They know that I care and want to further increase the protection because the safety of my employees has always been very important to me. When employees feel safe, they convey it to patients. That’s why our patients are now less insecure and continue to come regularly.
Will the device be available for other practices in the near future?
I am very open to that idea. The dental industry has already shown interest, and I have had appointments with representatives. They are interested because they have not solved the problem so far. I have also received enquiries from dentists from other practices all over Germany, and some of them have offered money for the device. However, I turned them down because the devices are only prototypes so far. We have two prototypes, the Terminator 1 for dentistry and the Terminator 2 (T2), which is only for air purification. An engineering office offered me support to get the product ready for market.
Can the device be used for other purposes?
Yes, for all areas where aerosols are produced. For example, it could be used for all kinds of laser applications, for ear, nose and throat treatment, or in ambulances. The T2 has no filter and is a small model, so it is easy to transport. It could be used in restaurants, taxis and all public transport. Of course, it does not offer 100% safety, because there is no such thing, but the device reduces the probability of infection.