3D Printing and Orthodontics

By Dr. Christian Groth

As we move towards the 2015 AAO Annual Session in San Francisco many of us will be making check lists for items to investigate at the exhibition hall and lectures. Anybody who has attended recent meetings has seen that intraoral scanners are a hot topic. Every year new products are being released, or updates to current systems are offered. Intraoral scanning has opened the door for additional technologies within (and outside of) the orthodontic office. Dr. John White wrote a very informative blog post in February talking about the use of intraoral scanning for same day consultations (click here to read it). As more people are offering clear aligner therapy (including general dentists and the mail order aligner system that we all know about) it is time that we differentiate ourselves as orthodontic specialists. One way in which we can do this is to incorporate 3D printing into our daily practices.

3D printing, also known as additive manufacturing, is a process by which a physical object is created from a digital file (check out a video of 3D printed models here). There are several different types of 3D printers available that range in price from a few hundred dollars to almost one hundred thousand dollars. They all have one thing in common: they build models layer-by-layer with a build platform that moves vertically. The smaller the layer thickness the better looking the model will be. The four most popular types of printers are: Fused Deposition Modeling (FDM), Stereolithography (SLA), Digital Light Projector (DLP), and Polyjet Photopolymer (PP). Without getting too technical here is how each basically works. FDM involved heating up a thin strand of plastic resin that comes off of a spool and is deposited in layers as thin as 100 microns. SLA and DLP technologies are similar in that they utilize a vat of liquid, photosensitive resin. When the light hits the resin it is cured and platform moves to enable the next layer to be cured. The different between SLA and DLP is that SLA uses a single laser point to draw an image whereas DLP uses a projected image to cure a whole layer simultaneously, which allows the printing process to move faster (think of this as the difference between drawing a picture and stamping a picture). PP printers are probably the most popular in dentistry and use inkjet technology (yes, just like your desktop printer). Liquid resin is jetted out of nozzles in an extremely accurate fashion and cured by a UV. Layer thickness of SLA, DLP, and PP printers can be as low as 16 microns (for your reference the average piece of paper is 100 microns thick).

While the technologies differ between printers what truly sets them apart is the quality of the parts. Cheap printers are made from cheap parts that can degrade over time and result in inaccurate models. It is truly a case of you get what you pay for. So if you are in the market for a 3D printer to be used in your practice, buy the best one that you can afford.

3D printed models can be used for anything in the orthodontic office.   The most practical use is for retention and relapse treatment. A major downside to stone models is that they are often destroyed during the retainer fabrication process. 3D printed models do not get ruined and can be used as many times as necessary for retainer fabrication. Imagine being able to print a model, make a clear retainer, and mail it off to a patient who is away at college. What a service you have just provided to your patient and they never stepped foot in your office! Pairing 3D printing with one of several software programs available allows us to create sequential setups/models for minor tooth movement. By controlling the process we control the overhead and thus have the ability to pass these savings on to the patient. Another great service that we can offer our patients if they have a lapse in retainer wear.

Whatever your practice is like there is a place for 3D printed models in it. While you will pay a little bit more for the physical model, the longevity, versatility, patient excitement, and ability to virtually eliminate alginate impressions from your practice will pay off in the end!

The Digital Generations

By Anthony M. Puntillo DDS, MSD

Dr.-Puntillo-PictureThe majority of the U.S. Workforce today is comprised of three generations:  Boomers (1946-64), Xers (1965-80) and Millennials (1981-99), each generation with its own unique set of characteristics.  The American Association of Orthodontists (AAO) now reports that more than 51% of its membership is composed of Gen Xers and Millennials.  By virtue of their birth timing Xers and Millennials, including myself (1966), were the first generations to grow up with computers in their homes.  Although Gen Xers differ from Millennials in many ways, technology is now ingrained into nearly every part of both generations’ lives.  For those Xers and Millenials that also happen to be orthodontists, this attachment to technology includes not only their personal lives, but also their orthodontic practices.

Over the last few years, my blog posts have centered on the discussion of a “Digital Orthodontic Practice.”  A digital practice must include not only the management and record keeping aspects (paperless) of our offices, but also clinical diagnosis and tooth alignment functions.  In this post, I want to highlight the current opportunities for moving digital in the clinical portion of your practice.

Diagnosis:

The clinical care for most orthodontic patients begins with a diagnosis and a treatment plan.  Given that Kodak is now only a shell of the company that it once was, I think it is safe to say most orthodontic practices are now taking digital photographs, instead of film, as part of their diagnostic records.  The recent 2014 JCO study of Orthodontic Diagnosis and Treatment Procedures1 found that more than 91% of the respondents used digital radiography, 69% used CBCT either routinely or occasionally, 41% used digital models and 28% used intraoral digital scanners.  Additionally,  the American Board of Orthodontics (ABO) recently announced that all initial models for their exam must be submitted in a digital format.  While the JCO survey included a relatively low number of respondents (n=135), I believe the findings are indicative of the Electronic Health Record (EHR) movement in all of the health care profession.  This movement, aided by government mandates and subsidies, has now breached the threshold level.  The train has left the station.  If you and your practice intend to stay relevant over the next decade, you absolutely need to be utilizing digital diagnostic records.

Tooth Alignment:

As our profession transitions to a digital diagnostic record norm, some are looking to move beyond diagnosis to digitally construct tooth aligning appliances.  In 1999, Align Technology opened the door to digital orthodontic tooth alignment with the introduction of the Invisalign system.  The system at that time relied upon traditional dental impressions, but today intraoral scanners and 3D printing have allowed for the elimination of the impression procedure.  Whether it be Align, or any other current Clear Aligner option, a digital model (.STL) of a patient’s dentition can be captured with a scanner, the teeth can be aligned using computer software, and treatment appliances (clear aligners) can be fabricated by machines based off of the digital “plan”.  Furthermore, this process can now also be utilized for patients using traditional bonded brackets.  Custom brackets along with custom bracket placement jigs and custom wires digitally planned and robotically bent are possible.  In large part because of costs and the learning curve, the digitization of clinical orthodontic procedures has not yet been completely accepted.   However, as the techniques become more refined, we should expect the cost to include them into our practices to decrease and implementation by the tech savvy Xers and Millennials to accelerate.  If you are an Xer or a Millennial, and have not already incorporated digital tooth alignment into your practice, you should be planning to do so in the near future.  If you are a Boomer, and potentially less comfortable with technology, you need to consider if you can afford to ignore this change.

Creating an esthetically pleasing and stable smile, can be a bit like designing and constructing a building.  In a recent conversation with a Boomer architect friend of mine he described the digital changes his profession has undergone.  My friend reported that my office, built in the year 2000, was one of the last buildings he drew by hand.  All of his projects now are digitally designed using 3D CAD technology, allowing him to plan and visualize the end construction result more effectively.  The transition in the architectural profession took time and learning.  Change is never easy.  However, as my friend now approaches the end of his career, he finds the “old” way inefficient and less accurate.   Whatever generation you were been born into, I encourage you to embrace the digital change our profession is in the midst of.  I am certain a digital orthodontics will ultimately benefit you and your patients.

1Keim Et.Al. 2014 JCO Study of Orthodontic Diagnosis and Treatment Procedures, Part 1: Results and Trends Journal of Clinical Orthodontics 2014; 48:10 pages 607-630.