Comparing 3D-Printed and Traditional Guide Plates for Placing Orthodontic Brackets

The most important part of orthodontic treatment is the correct positioning and bonding of the brackets. Direct bonding is less accurate and often takes longer due to saliva and inaccessible tooth positions, while indirect bonding is quicker and less likely to cause bracket positioning errors, but is costlier. A team of researchers from Beijing published a paper, “Comparison of three-dimensional printing guides and double-layer guide plates in accurate bracket placement,” where they designed different types of transfer trays, using 3D printing and traditional impressions, and evaluated their “clinical efficacy.”

“With the increasing applications of indirect bonding, various designs of transfer trays and novel technologies are implemented in the treatment procedure. In the laboratory stage, the patients’ occlusal interrelationship can be duplicated either by impression or digital scanning,” the researchers wrote. “The former is a traditional method to generate double-layer guide plates; though with a lower cost, this method typically takes longer laboratory time and is susceptible to human errors. The latter is incorporated with cutting-edge 3D printing technology that provides various advantages, such as precise 3D images, convenience in file storage, and accuracy in image analysis and outcome prediction [5].”

The study model. (a) Maxillary model with marking points. (b) Mandibular model with marking points.

In the laboratory stage of indirect bonding, brackets are bonded to the patient’s orthodontic model, and then a customized transfer tray is used to place them on the actual surface of the tooth in the clinical stage. To make the models for this study, the team collected 140 teeth with normal crown morphology and no evident defects or restorations, sterilized them, and arranged them into “five pairs of full dentition” before labeling the marking points “on the buccal/labial surface of the crown.”

Digital design and 3D printing guides. (a) Distinguishing teeth and gingiva on the digital models. (b) Establishing the occlusal plane. (c) Adjusting the bracket positioning. (d) Simulation of bracket positioning. (e-f) Guide plate for indirect bonding on digital models. (g) 3D printing guide – whole denture type, and (h) single tooth type.

Next, they created 3D printable indirect bonding guide plates, beginning by generating digital models with the 3Shape TRIOS Standard intraoral scanner. The occlusal plane, axis, and center of individual crowns were established, and the marginal gingiva labeled, using 3Shape software, and guide plates for the whole denture type and single tooth type for 3D printed on a ProJet 3510 DP.

“The brackets were positioned in the 3D printing guides (the whole denture type or the single tooth type), and 3 M Unitek Transbond™ XT light-curable adhesives were applied to the base of the brackets,” the team explained about the indirect bonding procedure. “The 3D printing guides were then placed on the study models, and each border of the brackets was light-cured for 5 s.”

3D printing guides and indirect bonding procedure. 3D printing guide of the (a) maxillary and (b) mandibular dentitions. 3D printing guides placed on the (c) maxillary and (d) mandibular study models. Completion of bracket positioning on the (e) maxillary and (f) mandibular study models.

In making the traditional trays, the researchers used silicone-based materials to get impressions of the working models with intact marking points, and created plaster casts from the silicone molds.

“A thin layer of separation agents was applied to the cast tooth surfaces; then, the brackets were positioned and adhered on the crowns using 3 M Transbond™ XT light-curable adhesives and light-cured for 5 min,” they wrote. “Double-layer guide plates were manufactured by Erkoform-3D Thermoformer with a 1 mm inner layer (soft film) and 0.6 mm or 0.8 mm outer layer (hard film). Lastly, we trimmed the excess materials of the inner layer to 2 mm above the crowns and the outer layer until covering 2/3 of the brackets.”

The impression of (a) maxillary and (b) mandibular dentitions, and the plaster casts of (c) maxillary and (d) mandibular dentitions.

Bracket positioning on the (a-c) maxillary and (d-f) mandibular dentitions. Double-layer guide plate of the (g) maxillary and (h) mandibular dentitions.

For this indirect bonding procedure, the bracket were placed in the double-layer guide plates, with one solution applied to the surfaces of the teeth and another to the bracket base. Then, the guide plates were put on the study models, and after two minutes of fixation, the researchers removed the outer hard layer first, and then the inner soft layer.

Double-layer guide plates placed on the (a-c) maxillary and (d-f) mandibular study models. Completion of bracket positioning on the (g-i) maxillary and (j-l) mandibular study models.

Next, Materialise Mimics software was used to measure the distance between the marking points and bracket positions in the digital models of both the whole denture and single tooth designs for the 3D printed guide group, while electronic calipers measured the distance in the study models.

Electronic caliper.

Marking points on the plaster cast and study model.

SPSS software was used to analyze the distance.

“The accuracy of indirect bonding between 3D printing guide and double-layer guide plate was compared using the paired t-test. P < 0.05 indicated statistical significance,” they explained.

The data, reflected in the tables below, showed that there was no statistical difference in the accuracy of bracket positioning between the two types (p = 0.078), and that the 0.6 mm type in the double-layer guide group had much better results (p = 0.036) than the 0.8 mm one.

“We then further compared the accuracy of indirect bonding between 3D printing guides (whole denture type) and double-layer guide plates (0.6 mm), the results were comparable between two groups (P = 0.069),” they wrote. “However, indirect bonding using double-layer guide plates (0.6 mm) cost less chair-side time than the 3D printing guides group.”

Table 1: Comparison of different designs in 3D printing guide group.

Table 2: Comparison of different designs in double-layer guide plate group.

Table 3: Comparison of bracket positioning accuracy between 3D printing guide and double-layer guide plate.

However, while the data showed no statistical significance, the researchers noted that “the overall discrepancy before and after bracket transfer was lower in the 3D printing guides group.”

“This finding might be due to our in vitro study models with only mild malocclusion,” they explained. “Further in vivo studies in more severe clinical cases, such as malocclusion with torsion/tilting/overlapping, will be essential to investigate the efficacy and generalizability of 3D printing guides and double-layer guide plates.”

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Introducing LightForce Orthodontics and Its Customized 3D Printed Bracket System

The LightForce Orthodontics team. L-R: Kelsey Peterson-Fafara, Dr. Alfred Griffin, Craig Sidorchuk, and Dr. Lou Shuman.

A dental resident walked into a bar full of Harvard graduate students. No, it’s not the beginning of a bad joke, but actually the genesis of venture-backed startup LightForce Orthodontics, which officially launched at this year’s American Association of Orthodontists (AAO) Annual Session. The team is making what it calls the world’s first customized 3D printed bracket system for the digital orthodontics field.

The startup’s founder and CEO, Dr. Alfred Griffin, comes from a long line of dentists, and had just completed a combined dental and PhD program at the Medical University of South Carolina before moving to Boston in 2015 to attend the Harvard School of Dental Medicine for his residency. He wasn’t used to the whiteout conditions of a hard New England winter, and spent a lot of time holed up in his apartment, dreaming up the innovative bracket system.

Dr. Larry Andrews and A-Company first introduced fully programmed brackets in 1970, and not a lot has changed since then.

“Standard orthodontic prescriptions are essentially a compromise from the outset,” explained Dr. Griffin in the special edition AAO issue of this year’s Orthodontic Practice US. “They are an “all patients equal” proposition. But no two patients have exactly the same tooth morphology or exactly the same bite. So why would we think they should all have the same ‘ideal’ finish?

“The concessions with pre-programmed brackets have been imposed by several constraining factors. Two of the primary constraints are inflexible bracket manufacturing technologies and the imprecision of analog treatment planning.”

It costs hundreds of thousands of dollars and takes anywhere from six to twelve months, using injection molding, to create molds for one standard prescription, which is about 20 brackets of different programming and shapes – not a realistic environment for patient-specific customization. So Dr. Griffin turned to 3D printing, which already has many applications in the dental and orthodontics fields, such as creating aligners, molds, implants, dentures, and even braces.

Most braces are “off the rack,” and even though skilled orthodontists can make this work, Dr. Griffin knew that 3D printing, which is a good fit for custom applications, could be used to make patient-specific braces. So he created a patented system for 3D printed orthodontic treatment brackets, using material nearly identical to injection modeled ceramic brackets but that’s been formulated specifically for 3D printing.

“Delivering a patient-specific prescription for each case, the LightForce system is unlike anything you’ve ever used,” claims the website. “Each bracket is custom created and 3D-printed, bringing a new level of flexibility and clinical possibilities. This enhances treatment efficiency and minimizes time-consuming adjustments in all phases of treatment.”

That same snowy winter, Dr. Griffin attended a local happy hour with Harvard graduate students, and after buying a few rounds, explained his idea to the group. Engineer Kelsey Peterson-Fafara immediately recognized the potential, and would soon be employee #1. Not long after LightForce, originally titled Signature Orthodontics, was accepted into the Harvard Innovation Lab accelerator, Dr. Griffin met orthodontist Dr. Lou Shuman, who had been an important member of the executive team for another dental company using 3D printing: Invisalign. He soon asked Dr. Shuman to be the company’s co-founder, and help reach out to the venture capital community.

LightForce Orthodontics was one of 128 applicants chosen to join the MassChallenge Accelerator program in 2016, and became entrepreneurs-in-residence at the MassChallenge facility, later receiving $50,000 in equity-free financing as one of the 15 winners. The next step was locking down venture capital, but Dr. Griffin didn’t want to work with just anyone – he was looking to change how orthodontics works at a fundamental level, not just for a cash grab. The company’s first major funding came from AM Ventures (AMV), which is dedicated to investing in 3D printing.

“We wanted a strategic investor — not just someone with money,” Dr. Shuman said. “We wanted expertise in our fundamental technology. AMV was an ideal partner for LightForce.”

Speaking of expertise, AMV introduced Dr. Griffin and Dr. Shuman to EOS founder and industry pioneer Hans Langer, who believes that LightForce has achieved the two most important components in the future of 3D printing: creating high value customization, and having a market that’s large enough to support it.


LightForce continued to grow, staying on as Alumni in Residence at MassChallenge through 2017, hiring expert dental software developers, finalizing the bracket design, and receiving FDA clearance for the system. The startup closed its Series A funding round last summer, enjoyed a successful debut at the 2019 AAO Annual Session, and has multiple patients in treatment who wanted to be the first to sport customized, 3D printed braces.

The brackets can be perfectly contoured to any tooth morphology. The initial system was made to compete with metal brackets, and LightForce is now working on higher-aesthetic options and looking at different materials, as well as perfecting its service and supply chain logistics. It’s a simple three-step digital workflow: scan, create the 3D model, and print. The online interface is intuitive, with cloud-based treatment planning software that allows users to make adjustments directly on the model, before the custom 3D printed appliance is shipped in just 7-10 business days after approval.

In order to keep up with a changing industry, LightForce’s treatment planning system will keep evolving as necessary. Aligners are becoming more capable, but many orthodontists still use braces for their patients, which is why LightForce is looking at the larger marketplace.

Dr. Griffin explained, “We don’t want to bring the idea to market and say `here’s how to use it.` We want to bring this to the orthodontist and ask them, ‘What can you do with it?’”

As direct-to-consumer companies gain popularity, Dr. Griffin wants the startup to acknowledge the expertise of the orthodontic community, and help the field, not just take it over.

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3D Printed Syringe Bracket Reduces Chances for Bacterial Contamination

If you have ever experienced a major illness or serious injury, most likely you were extremely thankful for the medical professionals who helped you get your life back; however, it can be both distressing and frustrating—not to mention life-threatening—when doctors or nurses make mistakes that could have grave consequences. US researchers want to make even greater strides to improve safety mechanisms in both storing and preparing of anesthetic medications, outlined in the recently published ‘Anesthesia Workspace Cleanliness and Safety: Implementation of a Novel Syringe Bracket Using 3D Printing Techniques.’

There may be standards in place, and processes for avoiding syringe contamination and medication swaps, but as the authors point out, ‘wide variability’ persists. This is concerning—and dangerous for patients with all too common errors like:

  • Delayed responses to critical changes in patient status
  • Syringe swaps
  • Environmental contamination of syringes
  • Cross-contamination of syringes between patients

Even with new standardizations like prefilled syringes and automated labeling, there are errors—enough to present ‘widespread challenges.’ The problem is so bad that data shows one in fifteen syringes to be contaminated with ‘potentially pathogenic bacteria.’

Prototype syringe bracket with removable support structures printed with a desktop stereolithography 3D printer

“A growing body of evidence had linked postoperative healthcare-associated infections to such microorganisms within the anesthesia workspace, prompting the recent release of the Society for Healthcare Epidemiology of America’s first infection prevention guidelines for the anesthesia work area,” state the researchers.

In seeking solutions for a better quality of care for patients, the research team considered ways to improve the following:

  • Handling
  • Availability
  • Standardization of key medications in the anesthesia workspace

After studying common causes of such mishaps, the research team came to a very important conclusion: rather than just delivering mandates to medical personnel regarding their need to change their behaviors, the whole system needs to be re-engineered—with better tools and better organization to prevent errors.

The project, a ‘quality improvement initiative,’ was completed at Massachusetts General Hospital, as the researchers assessed a baseline in terms of routine practices, developed a device for better organization, and then evaluated provider practices. They used 3D printing to create an organizational device for better safety and efficiency overall. So far, the researchers have tested and used the new 3D printed device in 60 operating rooms at one medical facility with ongoing postintervention surveys and workspace audits a year later.

Serial syringe bracket designs based on iterative prototyping and user feedback: (a) initial prototype, (b) elevation of main surface to provide further clearance from anesthesia machine display, (c) alternative slot configuration using flange to hold syringe and allow front loading and unloading, (d) corner-mounted design including holders for unopened medication vials and a bougie, (e) anterior extension of the main surface to provide further clearance from machines with mounted depth of anesthesia monitors, (f ) final design with wider support clip for increased stability. A detailed review of the rationale and utility of each of these design features is provided in Supplementary Table 2.

Their 3D printable syringe bracket system is open-source, operating as a cognitive aid and a way to prevent contamination. Prototypes were created on a Formlabs Form 2, in a series of customized brackets meant to be attached to the anesthesia machine. The goal is for the syringe bracket to reduce ‘transmission events’ by preventing environmental contamination—and offering a way to clearly distinguish emergency medications from those already accessed for another patient. The researchers also developed a ‘one-way’ system for syringes to be accessed only one time and then never placed back in the bracket.

Surveys indicated ‘significantly higher levels of confidence’ in knowing there was a more secure process in place; in fact, 76.2 percent of respondents reported more than 95 percent confidence in knowing where medications where ‘during supervision or handoffs,’ as opposed to the original baseline of 43.7 percent.

“One year after deployment, 94% of users reported that they found the device to be helpful, 96.3% expressed a desire to have the brackets expanded to nonoperating room anesthetizing locations, and 96.2% would like to have them in other hospitals where they may work at present or in the future,” concluded the researchers.

“Measures of practitioner adoption and satisfaction with the device one year after implementation suggest that this intervention resulted in a high-value, meaningful culture change and may yield similar improvements outside of our own institution.”

While 3D printing has made huge impacts within bioprinting and the creation of devices and implants directly affecting patients—offering a better quality of life—this technology has also been responsible for a variety of different models and mechanisms that allow for improved, more efficient processes in hospitals. Find out more about the new syringe bracket here. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Final selective laser-sintering 3D-printed bracket and accompanying bougie holder in use. ‘e bracket clips securely to the corner of the anesthesia machine and accepts five 10–20 mL BD syringes (standard setup including phenylephrine, ephedrine, glycopyrrolate, succinylcholine, and propofol shown).

[Source / Images: ‘Anesthesia Workspace Cleanliness and Safety: Implementation of a Novel Syringe Bracket Using 3D Printing Techniques’]

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Top 10 3D Printing Aerospace Stories from 2018

3D printing has played an important role in many industries over the past year, such as medical, education, and aerospace. It would take a very long time to list all of the amazing news in aerospace 3D printing in 2018, which is why we’ve chosen our top 10 stories for you about 3D printing in the aerospace industry and put them all in a single article.

Sintavia Received Approval to 3D Print Production Parts for Honeywell Aerospace

Tier One metal 3D printer manufacturer Sintavia LLC, headquartered in Florida, announced in January that it is the first company to receive internal approval to 3D print flightworthy production parts, using a powder bed fusion process, for OEM Honeywell Aerospace. Sintavia’s exciting approval covers all of Honeywell’s programs.

Boeing and Oerlikon Developing Standard Processes

Boeing, the world’s largest aerospace company, signed a five-year collaboration agreement with Swiss technology and engineering group Oerlikon to develop standard processes and materials for metal 3D printing. Together, the two companies will use the data resulting from their agreement to support the creation of standard titanium 3D printing processes, in addition to the qualification of AM suppliers that will produce metallic components through a variety of different materials and machines. Their research will focus first on industrializing titanium powder bed fusion, as well as making sure that any parts made with the process will meet the necessary flight requirements of both the FAA and the Department of Defense.

FITNIK Launched Operations in Russia

In 2017, FIT AG, a German provider of rapid prototyping and additive design and manufacturing (ADM) services, began working with Russian research and engineering company NIK Ltd. to open up the country’s market for aerospace additive manufacturing. FIT and NIK started a new joint venture company, dubbed FITNIK, which combines the best of what both companies offer. In the winter of 2018, FITNIK finally launched its operations in the strategic location of Zhukovsky, which is an important aircraft R&D center.

New Polymer 3D Printing Standards for Aerospace Industry

The National Institute for Aviation Research (NIAR) at Wichita State University (WSU), which is the country’s largest university aviation R&D institution, announced that it would be helping to create new technical standard documents for polymer 3D printing in the aerospace industry, together with the Polymer Additive Manufacturing (AMS AM-P) Subcommittee of global engineering organization SAE International. These new technical standard documents are supporting the industry’s interest in qualifying 3D printed polymer parts, as well as providing quality assurance provisions and technical requirements for the material feedstock characterization and FDM process that will be used to 3D print high-quality aerospace parts with Stratasys ULTEM 9085 and ULTEM 1010.

Premium AEROTEC Acquired APWORKS

Metal 3D printing expert and Airbus subsidiary APWORKS announced in April that it had been acquired as a subsidiary by aerostructures supplier Premium AEROTEC. Premium AEROTEC will be the sole shareholder, with APWORKS maintaining its own market presence as an independent company. Combining the two companies gave clients access to 11 production units and a wide variety of materials.

Gefertec’s Wire-Feed 3D Printing Developed for Aerospace

Gefertec, which uses wire as the feedstock for its patented 3DMP technology, worked with the Bremer Institut für Angewandte Strahltechnik GmbH (BIAS) to qualify its wire-feed 3D printing method to produce large structural aerospace components. The research took place as part of collaborative project REGIS, which includes several different partners from the aerospace industry, other research institutions, and machine manufacturers. Germany’s Federal Ministry for Economic Affairs and Energy funded the project, which investigated the influence of shielding gas content and heat input on the mechanical properties of titanium and aluminium components.

Research Into Embedded QR Codes for Aerospace 3D Printing

It’s been predicted that by 2021, 75% of new commercial and military aircraft will contain 3D printed parts, so it’s vitally important to find a way to ensure that 3D printed components are genuine, and not counterfeit. A group of researchers from the NYU Tandon School of Engineering came up with a way to protect part integrity by converting QR codes, bar codes, and other passive tags into 3D features that are hidden inside 3D printed objects. The researchers explained in a paper how they were able to embed the codes in a way that they would neither compromise the integrity of the 3D printed object or be obvious to any counterfeiters attempting to reverse engineer the part.

Lockheed Martin Received Contract for Developing Aerospace 3D Printing

Aerospace company Lockheed Martin, the world’s largest defense contractor, was granted a $5.8 million contract with the Office of Naval Research to help further develop 3D printing for the aerospace industry. Together, the two will investigate the use of artificial intelligence in training robots to independently oversee the 3D printing of complex aerospace components.

BeAM And PFW Aerospace Qualified 3D Printed Aerospace Component

BeAM, well-known for its Directed Energy Deposition (DED) technology, announced a new partnership with German company PFW Aerospace, which supplies systems and components for all civilian Airbus models and the Boeing 737 Dreamliner. Together, the two worked to qualify a 3D printed aerospace component, made out of the Ti6Al4V alloy, for a large civil passenger aircraft, in addition to industrializing BeAM’s DED process to manufacture series components and testing the applicability of the method to machined titanium components and complex welding designs.

Researchers Qualified 3D Printed Aerospace Brackets

Speaking of parts qualification, a team of researchers completed a feasibility study of the Thermoelastic Stress Analysis (TSA) on a titanium alloy space bracket made with Electron Beam Melting (EBM) 3D printing, in order to ensure that its mechanical behavior and other qualities were acceptable. The researchers developed a methodology, which was implemented on a titanium based-alloy satellite bracket.

Discuss these stories and other 3D printing topics at 3DPrintBoard.com or share your thoughts below. 

Ford Opens New Advanced Manufacturing Center and Showcases 3D Printed Production Parts

Automotive manufacturer Ford has been incorporating 3D printing into its manufacturing procedures for years. Recently the company won three Automotive Innovation Awards for a 3D printed injection mold lifter action, a window alignment feature and an assembly lift assist. While those particular parts were not production parts, Ford is now attracting attention for another 3D printed part, this one to be used in the actual production of a vehicle – namely, the 2019 Ford Shelby Mustang GT 500.

Two 3D printed brackets will hold a brake line on the new Mustang – a brake line bracket breakthrough, you might call the development, as it demonstrates that 3D printed parts are viable as components in actual vehicles. The brackets and their manufacturing method will be showcased at the North American International Auto Show, which is taking place in Detroit in January.

Ford also recently opened a new $45 million Advanced Manufacturing Center in Redford, Michigan.

“More than 100 years ago, Ford created the moving assembly line, forever changing how vehicles would be mass-produced,” said Joe Hinrichs, Ford’s President of Global Operations. “Today, we are reinventing tomorrow’s assembly line – tapping technologies once only dreamed of on the big screen – to increase our manufacturing efficiency and quality.”

About 100 experts work at the facility, which Ford describes as a “development hub” for advanced technologies such as 3D printing, augmented and virtual reality, robotics, digital manufacturing and more. The Advanced Manufacturing Center has 23 3D printers and is working with 10 3D manufacturing companies, allowing Ford to develop applications with different materials including sand, nylon and carbon. One application currently under development has the potential to save the company more than $2 million.

In addition to the Shelby Mustang GT500, the F-150 Raptor, built for China, also has a 3D printed interior part. Worldwide, Ford has 90 3D printers being used to produce parts and tools. 3D printers aren’t new to Ford – the company bought the third 3D printer ever made in 1988 – but its use of the technology has been steadily growing.

At the Advanced Manufacturing Center, Ford is also using augmented and virtual reality to help it simulate and design assembly lines to build millions of vehicles. Ford workers use specialized gaming equipment to configure a virtual production line, which allows them to identify potentially hazardous maneuvers and fine-tune workflows before an actual assembly line is constructed. Ford is also developing specialized augmented and virtual reality experiences to allow manufacturing teams to work together around the world.

Then there are the robots – or cobots, aka collaborative robots. More than 100 of them are currently working in Ford plants around the world. These robots are small and can safely work collaboratively with people, without protective cages. Using them in the Advanced Manufacturing Center helps Ford to identify and address potential production issues before the cobots are installed in plants.

“While we are increasing our use of collaborative robots, we strongly believe there is a need for both people and robots,” said Hinrichs. “People are better at doing certain jobs, while robots are able to perform certain tasks, including those that are ergonomically taxing for people.”

Automotive manufacturing is looking very different than it did 50 years ago, or even a few years ago. Manufacturing jobs aren’t necessarily disappearing, though – they’re just changing, and Ford is an example of how humans can work alongside technology to create better products.

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[Images: Ford]