Dentist, Inventor, Townie By Thomas Giacobbi, DDS, FAGD, Editorial Director, Dentaltown Magazine

DT: What are the challenges for a dentist inventor?

McDonald: The key to inventiveness is to continually see problems and obstacles as opportunities to invent something. Given that dentistry is pretty difficult, there are quite a few opportunities! I love inventing and I frequently announce to my wife that I have “had another invention”! Most of them have either been invented before, are not financially or practically viable or are just plain stupid, but about 1 in 20 looks worthwhile.

One of the biggest challenges for me as a dentist inventor is managing my time. It is hard to have enough time to work in the practice while running a full-time business. There are many jobs that cannot easily be delegated to non-dentists as they don’t have the experience or knowledge. I am concerned that without direct patient contact new ideas for dental inventions may dry up.

DT: Please tell me about the new products that TrioDent is developing.

McDonald: TrioDent has quite a few products in development that can’t be disclosed yet. I would; however, like to tell you about our recently launched product, the V-Wedge, which nicely complements the V-Ring.

A wedge is an essential part of the Class II matrix system and it is clear to me that currently available wedges are not ideal. For example, they commonly demonstrate the following deficiencies:

1. Many wedges are small and difficult to hold;
2. Some have a sharp point that pierces the gingival papilla on the other side;
3. Most wedges only seal the gingival margin on the side that they were inserted and leave a gap on the other side;
4. Some wedges are straight in the vertical plane and they tend to push the matrix contact point too far towards the marginal ridge;
5. Many wedges are rigid and do not self-adapt to the proper form of the interproximal space;
6. And finally, some are difficult to remove.

After developing the novel “pull” Double-Wedge using a soft and elastic polymer, and thoroughly testing it in many situations, I became aware of its strengths and weaknesses and it because clear that there was a need for a better “push” wedge. However, coming up with an improvement was not so easy since wedges have been around a long time. The popular “wedge-on-a-stick” represented a good idea in that it provides a handle to hold the wedge, but unfortunately the snapping off of the handle is unpredictable and sometimes I have found that the twisting of the plastic stick can rotate the wedge too, which in turn can mangle the matrix and can set off gingival bleed.

Making a wedge easier to hold by using a re-usable “handle” seemed like an even better idea, so I started work on that and over a long period the shape of the new V-Wedge started to take place.

The key features of the new V-Wedge are:

1. The handle with a hole provides an excellent means to hold the wedge, particularly with the pin-tweezers, without which the wedge would be easy to drop. The hole is large enough for conventional cotton tweezers too.
2. The mid-section of the wedge is quite long and parallel and the wedge is flexible, which allows the wedge to seal the gingival margin of the matrix band at both the buccal and lingual side.
3. The inverted V-shaped cross-section gives the wedge flexibility allowing it to adapt to the contours of the interproximal space. The hollow V-shape provides a space for the gingival tissues. The thin edges tends to draw the V-Wedge down into the interproximal space rather than making rising up like many other wedges.
4. The banana-shaped curvature of the wedge enables the dentist to insert the wedge into the interproximal space without it piercing the gingival papilla on the other side.
5. The V-Wedge comes in two different polymers, a softer polymer and a harder one. This gives the clinician a great deal of choice as there are six different V-Wedges altogether. The color codes are easy to remember too. Small, medium and large are yellow, green and blue respectively. The softer polymer has the same color sequence but has a dark shade of the same color. The softer wedges are particularly useful anteriorly, although they are also good in the posterior teeth.

DT: How are you processing orders in the USA?

McDonald: The well-known Townie, Marshall White, DMD was an early fan of the Tri-Clip and he posted many clinical cases showing its use. Back in 2003, he called me several times to ask if he could be our US distributor. Eventually I agreed and Marshall set up TrioDent USA and a good working relationship developed between us. We were a small outfit and distributing directly from his dental office worked well for the first 18 months or so.

However, 2005 was a transitional year for TrioDent which suddenly grew from a “Mom & Pop” company into something more substantial. The introduction of the V-Ring system led to a huge jump in sales and it was clear that we needed some flexible resources that could respond to our rapid growth. So, TrioDentUSA moved out of Marshall’s dental office in Ohio to a new distribution center in Los Angeles at the beginning of 2006. The transition was not as smooth as we had hoped; we had delays in transferring the toll-free phone number, shipments from New Zealand were held up by the FDA because the paperwork wasn’t exactly right and we had some production delays at the factory. However, by the middle of February 2006 the problems were sorted and now the new system is working very well and most orders are sent out the next working day.

DT: Will you sell through distributors?

McDonald: Apart from TrioDentUSA, mentioned above, TrioDent has a couple of other USA distributors.

Practicon has been with us for quite a while selling both the Tri-Clip and the V-Ring. We understand from Practicon that the V-Ring system has been one of its best products ever.

Rodger “Rod” Kurthy, DMD recently become our latest distributor and has included the V-Ring in his fantastic DVD that was distributed to all dentists nation-wide in February this year. It was a delight to get to know Rod after presenting him with the TrioDent Star Townie Award for 2005 at the Townie Meeting in Las Vegas last year.

DT: What challenges do you face operating your company from New Zealand?

McDonald: There are some challenges, but the first thing I would like to say is that both the Internet and Dentaltown have made a massive difference. In fact, it is probably true to say that we wouldn’t have a business without Dentaltown. The exposure we got through the Dentaltown forums and the magazine advertising kept us afloat during the difficult early period of the business.

Coming back to the challenges, when I think about it, there aren’t all that many. Even though we are 6,000 miles away across the Pacific, I get my e-mails instantly, I have a US domestic phone and fax number, UPS parcels take about three days to get to LA and we can frequently talk by phone to our business partners in our morning and their afternoon.

Some of our biggest challenges have been the US Customs Department, not having a social security number and funny enough, our international phone number. I gave up on the last one and got a US phone number that calls me on my laptop via Skype.com. Today’s technology is truly fantastic!

DT: Are your products selling well in other countries?

McDonald: The American market is by far the biggest and best market in the world. Everyone speaks English and it is the home of Dentaltown, so we have put most of our effort there. In addition, we have been struggling to cope with the growing demand just from the USA, so expanding into other markets has had a low priority.

However, this year we appointed an International Marketing Manager to drive sales into other countries so we expect to see some growth in these areas. Sales of the V-Ring are strong in New Zealand, where we captured 15% of the market in 9 months purely with direct mail. They are also selling well in Australia and Germany and we have new distributors in England, Ireland, Israel, and the Benelux countries.

DT: Do you exhibit or lecture at US dental shows?

McDonald: Exhibiting at shows in the US is a challenge that we have yet to come to grips with. When we have more staff we will look at this more carefully, but at the moment I doubt that the huge effort required for us to get from New Zealand to American trade shows is worthwhile. Instead we are focusing on the direct-marketing approach.

DT: What do you see as the future for TrioDent?

McDonald: Our plans for the future are to continue to bring out more products that align with our mantra “Simple Solutions for Smart Dentists.” We have a good list of potential products and expect to bring out a new product every 6-12 months.

How the New V-Ring Sectional Matrix System Was Developed

If there is anything that gets Simon McDonald, the inventor of the Tri-Clip and V-Ring system, frustrated it is an awkward and inefficient procedure that produces unpredictable results – like Class II composites! He wasn’t alone. The Dentaltown forums are full of threads started by Townies who have had trouble getting tight contacts with composites.

So, Simon was with good company four years ago when he started his crusade to make Class II composite procedures easier, although he didn’t know it at the time. His first dental invention was the Tri-Clip, an all-in-one disposable matrix, wedge and retainer system. The Tri-Clip has been well received in the USA especially through the efforts of well-known Townie, Marshall White, DMD.

Simon started with an analysis of the products on the market. Basically there are two types: full matrix bands that go all the way around the tooth and sectional-matrix bands that go partially around the tooth. Both systems have many problems according to Simon. First, he decided to focus his attention on improving the sectional matrix systems for posterior composite Class II cavities.

On the list for improvment was the issue of the wedge and retainer spring getting in each other’s way. By making two tines on each side of the ring with a V-shaped gap between, enough room was created in the middle for the wedge (Figs. 1 and 2).

To be ideal, the retainer ring had to be strong, smaller and less bulky than others on the market. The idea of making it from super-elastic Nickel-Titanium sounded promising. He quickly had the design drawn up in a three-dimensional computer aided design program and then contracted a specialist NiTi manufacturer in the USA to make some NiTi prototypes. After 8 months of “nearly getting there,” the NiTi specialist gave up. Simon began working two days a week with a local engineer to solve the remaining problems. While analyzing the causes of their frustrations, they came up with the idea of a stainless steel inner ring with tines, surrounded by a containing NiTi spring.

During the development phase, Simon tried numerous variations of the V-Ring and each time he had the 3D CAD designer make the changes and produce drawings which the engineers then used to cut out the parts. It became apparent that tiny changes made large differences in how well the product worked. The whole process took about 18 months from the initial “aha!” to getting the product into production.

At the same time Simon was also thinking of ways to improve the sectional matrix. A breakthrough came with the idea of adding a “tab” along the top edge that could be used as a handle so that any kind of tweezers could be used to place the matrix. Conventional looking matrices with simple arcs were not acceptable to Simon, so he later insisted on more complex S-shaped proximal profiles, which provided better anatomical forms.

Back in the practice, he had been struggling to remove sectional matrices and this was much harder with nice tight contacts. He came up with the idea of a hole in the wings of the matrix so that it could be pulled out with a probe, but this created a safety issue. Gradually he developed the concept of a special type of tweezers with a tiny pin on one side and a hole on the other (Fig. 3).

The V-Ring and Tab-Matrix system was launched in Las Vegas at the Dentaltown meeting at the end of March 2005 and has received numerous rave reviews ever since. The V-Ring is available in USA from www.TrioDent.com or 1-800-811-3949.