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The first and final prototype of the Loupe Shield. From left to right: Vancouver-based periodontist Dr. Scott Yamaoka and his son Zach Yamaoka, design engineer at Dyson. (Image: Scott Yamaoka)
Iveta Ramonaite, Dental Tribune International

By Iveta Ramonaite, Dental Tribune International

Wed. 12. May 2021


The pandemic has caused professional and private challenges. However, some people managed to use this downtime to stimulate their creativity and to test their entrepreneurial skills. One of these people is Dr. Scott Yamaoka, who devoted his time and energy to creating a face shield that would protect his dental team and patients from SARS-CoV-2 infection in the workplace. In this interview, he and his son, Zach Yamaoka, tell Dental Tribune International how they turned their idea into a product—the next generation optical face shield that allows dentists to comfortably fit magnification loupes with fiber optic lighting.

First of all, congratulations on your invention! Could you start by telling our readers a bit about your creation and what led you to developing it at home in your garage, during the pandemic?
Dr. Scott Yamaoka: As the pandemic set in and dental offices shut down, I began thinking about how we could get back to work safely. It became clear that, moving forward, face shields would be necessary to protect our dental team and patients. Images of hospital workers helping COVID-19 patients were circulating in the news, and that really drove this message home.

At the outset of the pandemic, it was nearly impossible to get one of these shields, which were sold out everywhere. And even if you could somehow get one, I realized that the shields that were made of foam and plastic film and used by hospital workers would be ineffective in the dental environment, in which dental professionals require clarity, the accommodation of magnification loupes and fiber optic lighting. The only other options available were construction shields from the hardware store. But even those had sold out, and again, would not accommodate magnification and lighting.

Attempting to make my own shield seemed like a productive use of time and mental energy during the shutdown and gave me solace in that I could control a small part of my destiny and the outcome of the pandemic.

It is not easy to create a face shield that not only is pleasing to the eye but also has a protective function. Could you take our readers through the creation process and talk about some of the materials you used?
Dr. Scott Yamaoka: Creating the prototype was a matter of searching for available products that I could use to construct the basic components of the face shield: a head harness, a plastic attachment system and the plastic itself.

Dr. Scott Yamaoka during the first stages of the creative process. (Image: Scott Yamaoka)

While looking at industrial shields for welding and researching the construction industry, I had the idea to use a safety construction helmet. We had one at home. The benefits of the secure head harness provided the foundation, and the brim allowed space for optics and lights. Removing the top part of the helmet with a Dremel reduced the weight and also allowed the plastic material to adapt to the rim of the brim to secure the magnets.

Using magnets meant that dentists could efficiently change the sheets of visor plastic in between patient visits and replace them when they became damaged or scratched. Seeing magnets on our fridge for holding paper notes gave me the idea that they could be used to secure the plastic, provided they were strong enough to hold it. We have used rare-earth magnets to surgically move teeth, and similar products were available at the hardware store.

Visor plastic was not available anywhere at the time, so I thought that we could use acetate plastic from the overhead projectors we once used when I was in grade school. Fortunately, they were still on sale, but their clarity was not ideal. The plastic we are using now is imported from the U.K. and incorporates the latest advances in clarity, including proprietary nanosurface technology. One of the comments we receive the most is that people forget that they are wearing the shield!

Zach Yamaoka: As the shield developed, we incorporated more esthetic aspects. However, the function of the face shield has always been important, since things are only beautiful if they work. The thinness of the rim on the final product is the result of a desire to reduce weight. The square shape reduces glare from ambient light. The appearance of each component on the shield is tied to a functional aspect.

The face shield we see now required 58 prototypes. What did you learn in the process, and when did you know that the product was ready to be sold on the market?
Zach Yamaoka: The story of the Loupe Shield engineering is the story of three discoveries made while making 58 prototypes.

The first one was that dentists really liked the full head harness. The users of the safety helmet prototype commented that, compared with their current face shield with an elastic band, the full safety harness was more comfortable, secure during long operations and caused fewer headaches. When analyzing this feedback, we realized that the key is the top strap. It supports the weight of the face shield and alleviates pressure on the sides of the head.

The story of the Loupe Shield engineering is the story of three discoveries made while making 58 prototypes
— Zach Yamaoka, Dyson

The second discovery was that a square rim has better optical properties. Searching online, I came upon an image of a face shield where the visor was gently curved in the field of view. We wondered what would happen if we extended that principle further, so we adjusted the shape of our rim from a semicircle (curved at the front) to a square (flat at the front). From testing, we realized that this reduced optical distortion and minimized glare from ambient light. As optical clarity is paramount to dental professionals, we thought this would be a great feature.

Face shields in the making. (Image: Scott Yamaoka)

The third discovery was of an optical plastic technology initially developed for iPhone screen protectors. It turns out that the functional requirements of screen protectors, which are ultraclear and scratch-resistant, are similar to those of dental face shields. Combing this optical plastic with our square rim has resulted in a face shield that is virtually invisible and incredibly durable.

The next-generation Loupe Shield available today incorporates these three discoveries. It features a fully adjustable head harness with a top strap, a square rim with a flat front, and a visor that was coated using this optical plastic technology.

It’s hard to know when a product is ready for market. As a designer, the tendency is to continue to improve it, but this cannot go on forever; at some point you reach a local optimum. After completing the 58th prototype, we 3D-printed ten shields and sent them to dentists in the U.S., Canada, the U.K. and Germany. Eight of the dentists loved it. Common startup wisdom is that, if even one customer loves your product, it’s time to go to market, so that is what we did.

Dr. Yamaoka, how did collaborating with your son, an engineer, help achieve the final result?
Dr. Scott Yamaoka: Being able to express the clinical needs for shield protection and functionality to a design engineer whose training is to take a concept and bring it into reality has been invaluable. Zach was able to take a complicated prototype and simplify its design while addressing the key needs for clinical practice.

Securing appropriate PPE has been quite challenging for many dental professionals in the past year. Why should dental teams be excited about this invention, and how will it improve their workflow?
Dr. Scott Yamaoka: Using a face shield that had poor clarity, was frequently fogged and felt uncomfortable slowed down my work. Zach and I designed the Ambience face shield to tick off all the boxes of what I would want a face shield to be. When using it, I can achieve my pre-COVID-19 level of efficiency, with the added benefit of protection. Owing to its optical clarity, it does not affect the patient experience and interaction. I sometimes forget I am wearing it. Eye strain and neck issues have also improved for me, which is a benefit I expect others will experience as well.

Having the shield gives me the peace of mind to focus on the surgery and the patient. The benefits can be seen after surgery when the plastic face shield is covered with bioburden on the outside. Wearing the shield is a seamless minor inconvenience, as I am now much more aware of the ramifications of splatter on my face and loupes. This face shield has become an integral part of my practice.

Dental professionals at Dr. Scott Yamaoka’s practice wearing personal protective equipment, including the Loupe Shield. (Image: Scott Yamaoka)

Should dental professionals keep an eye out for new products?
Dr. Scott Yamaoka: The Loupe Shield is fantastic at keeping splatter and droplets off the clinician’s face. It does this without sacrificing comfort or clarity. One shortcoming of face shields, in general, is that, alone, they do not provide sufficient protection against aerosol. The clinician should still wear a respirator or mask. Some face shield products completely seal around the head to provide aerosol filtration. However, they are overly complex, hard to clean, don’t fit loupes and are pricey.

As more data indicates the importance of aerosol as a mode of transmission, the desire for face shields that can protect from both splatter and aerosol will likely increase. For now, the Loupe Shield with an N95 respirator is perfect for a clinician working in a high-concentration aerosol environment. In the future, developing a Loupe Shield that offers complete protection from both splatter and aerosol would be a natural progression.

Editorial note: More information about the face shield can be found here.

Face shields Infection control Magnification loupe Personal Protective Equipment

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