Monday, March 30, 2020

A Nifty DIY Respirator that has the Potential to Provide Better Filtration than N-95



One of the things I truly love about dentistry is the passion that many of us feel for the profession.  This morning's post is going to go right along with that sentiment.  As we all know, the big news story of the last month has been the novel Corona  Virus with can lead to Covid-19.

The virus originated in the province of Wuhan, China and then rapidly spread across borders, demonstrating how amazingly contagious the virus is.  As it initially began to infect people in China, doctors, public health officials, and epidemiologists tried to get a handle on how the virus managed to spread so rapidly and efficiently.

A virus has always been trickier to deal with than a bacterium for a variety of reasons.  We won't get into all of those here today, however I would like to detail ONE trait that a lot of folks  outside  of medical realms are unaware of.  A virus (or viral particle) is *tiny* compared to a true bacteria.  Due to their size, they can frequently get through filtration mediums that stop other infectious agents in their tracks.

In many practices of medicine, dentistry included, a surgical mask is part of the everyday PPE (Personal Protective Equipment) that practitioners wear.  The surgical mask is a 2 way street.  It not only protects the healthcare worker from receiving infectious particles from the patient, but it also prevents the patient from receiving infectious particles from the healthcare worker.

It's also the same story for gloves.  Studies that had been done back in the times when dental professionals worked without gloves found that bacteria from the mouths of patients seen on Monday could be cultured from under the fingernails of workers on Friday afternoon.  Basically that meant that every patient seen for a week left their bacteria on the dentist's hands and therefore into the patient's mouth.  Scary right?

But for this discussion we're going to concentrate of the mask.  Recent studies of the Novel Corona Virus show it to be somewhere between 140 nanometers and 60 nanometers in size while the average size of bacteria is around 300 nanometers.  Surgical masks usually filter to about 100 nanometers while N-95 respirators filter to 30 nanometers.

Surgical masks are designed to cover the moth and nose loosely but are not sized for individual fit.  However, N-95 Respirators are designed to fit the wearer closely.

As the Covid-19 pandemic has progressed we, in healthcare, have seen an incredible shortage of N-95 masks as there is a scramble to protect healthcare workers from becoming infected and potentially passing the virus along to other patients and healthcare providers.

Now one of my pet peeves, as many of you know, is that when someone asks why we do something a certain way, the answer is "because we've always done it that way."  That's just a plain lousy answer.  So the question I've been asking the past week or 2 is "why do we always buy masks from distributors" and the answer is... you guessed it.

Then I came across a small website called  This website was put together by Dr. Mark Causey who is an orthodontist in Georgia.  Dr. Causey is a forward thinking guy and uses a 3D printer in his office.  His idea was, rather than buy N-95 masks and then throw them away, why not print a N-95 framework that you could theoretically use for years and simply replace the filtration when it was no longer working.  Genius!  Dr. Causey even designed the framework, saved it in an stl file, and made it available *for free* on his website.

His thought process is that if everyone that has a 3D printer started to produce these frameworks, we might very well cut the N-95 mask shortage.  His website goes through the entire process of creating a N-95 mask from a printed frame and readily available HEPA filters.

Since discovering this website, I've been printing these mask substructures pretty much non-stop on my Ender-3 printer in my home.

We are now creating masks that help prevent the spread of the Novel Corona Virus while also keeping masks out of the landfill.

I'll be doing more posts on this fascinating subject in the next few days.  I'm proud of Dr. Causey for his hard work and outside the box thinking.

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