The team behind GT Smiles has been developing advanced polymer materials for dentistry for decades. We built on years of research and experience in material safety and functionality to produce our GT FLEX ® family of thermoforming materials for aligners, retainers, and similar devices – including our latest, plant-based option: GT FLEX ® GREEN.
GT FLEX ® Thermoforming Materials
Our GT FLEX ® family of materials – including PRO, MAX, and GREEN – are engineered specifically for use in dental devices like retainers, aligners, night guards, and oral appliances for sleep apnea.
| GT FLEX ® PRO | GT FLEX ® MAX | GT FLEX ® GREEN |
|---|---|---|
 |  |  |
| Traditional Plastic | Traditional Plastic | Plant-Based Material |
| Clear | Clear | Pearly White |
| Long history of use by thousands of patients; trusted and reliable | Our thinnest material option; designed for added comfort | 100% free from traditional plastics; for anyone looking for plant-based alternatives |
GT FLEX ® PRO and GT FLEX ® MAX are traditional plastic options that have been proven through years of use by hundreds of thousands of patients and dentists worldwide.
GT FLEX ® GREEN is our patent-pending, plant-based plastic alternative. The GT FLEX ® GREEN materials are 100% free from traditional, petroleum-based plastics.
- They include a combination of 100% plant-based, bio-based, and other naturally-occurring components.
- They’re engineered specifically for dental applications like retainers, aligners, night guards, and oral appliances.
- And they’re formulated to help address growing patient concerns about toxicity and microplastics.
We’re working to have a GT FLEX ® GREEN option for all GT Smiles devices. It’s already available for retainers; night guards are on the way soon; aligners and oral appliances are in progress; and even more GREEN projects are underway… So if it’s a GT Smiles device and you don’t see GT FLEX ® GREEN as an option quite yet, stay tuned – we’re working on it!
A Deep Dive into GT FLEX ® GREEN
Let’s be clear: while we stand by our traditional plastic materials as tested and proven options (for now), GT Smiles is focused on further developing and supporting GT FLEX ® GREEN as the better choice for the future.
Here we’ll be focusing on GT FLEX ® GREEN…
BPA-Free, Latex-Free, Phthalate-Free, and Dye-Free
BPA, latex, and phthalates are associated with traditional plastic. GT FLEX ® GREEN is 100% free from traditional plastic. And none of the components that go into GT FLEX ® GREEN contain these chemicals.
We did considered dyes as an option because “food-safe” dyes do exist. But increasing patient concerns about dyes in general led us to keep them out of the GT FLEX ® GREEN formulations altogether.
Safety Tested
GT FLEX ® GREEN has been evaluated by independent, third-party testing laboratories for multiple safety-related criteria. The results indicate that GT FLEX ® GREEN is a safe, non-toxic solution for a variety of intraoral devices.
Biocompatibility Testing
Materials used for aligners, retainers, night guards, and the like generally must pass at least the following three biocompatibility tests:
- In Vitro Cytotoxicity (ISO 10993-5:2009)
- Skin Sensitization (ISO 10993-10:2021)
- Skin Irritation (ISO 10993-23:2021 – tests for Irritation)
GT FLEX ® GREEN has passed those three tests plus three additional tests we added for a more thorough evaluation:
- Oral Mucosa Irritation (ISO 10993-23:2021 – tests for Irritation)
- Acute Systemic Toxicity (ISO 10993-11:2017 – tests for Systemic Toxicity)
- Material Mediated Pyrogenicity (ISO 10993-11:2017 – tests for Systemic Toxicity)
Extractables and Leachables (E&L) Testing
GT FLEX ® GREEN is formulated intentionally to be degradable (it’s a required feature for addressing microplastics concerns), so it’s even more important for us to evaluate what might get released from the material as it starts to degrade.
To address this question, we submitted the material for extensive “extractables and leachables” testing.
In these tests, the material is subjected to “worst case scenario” environments (e.g. much stronger acids than would be present in the mouth) in order to try to get it to degrade as quickly as possible. The resulting mix of extracted and leached substances is then tested for the presence of each of following:
- Elemental Impurities
- Volatile Organic Compounds
- Semi-Volatile Organic Compounds
- Non-Volatile Organic Compounds
These tests found no cause for concern from anything extracted from GT FLEX ® GREEN, even under “worst case” conditions triggering aggressive degradation.
Engineered for Performance
Building on years of experience with our GT FLEX ® traditional plastic materials (ORIGINAL, PRO, and MAX), which have been used to make millions of devices worldwide, we engineered GT FLEX ® GREEN to deliver world-class material properties, optimized for aligners, retainers, night guards, and related devices.
Flexibility
Strength
Carefully Formulated for Biodegradability
If you’re not careful with your chemistry, you can start with plant- or bio-based ingredients and still end up making a material that lasts for decades or centuries without degrading, which means you still have a microplastics problem.
On the other hand, you can also start with these same ingredients and make a material that degrades in days, which wouldn’t be very useful for dental devices.
With GT FLEX ® GREEN, we worked hard to find an ideal balance allowing the material to last for a reasonable amount of time in the mouth while also being biodegradable.
In the form of a complete device, it’s been shown to last for months under normal, intraoral use conditions without showing obvious signs of degradation.
In the form of small particles (think microplastics), it’s been shown in initial third-party testing to degrade under simulated digestive conditions rather than persisting indefinitely. Further testing is also underway on this front.
What About Eco-Friendliness?
One of our core goals with GT FLEX ® GREEN is to help address the spiraling problem of traditional plastic waste.
We hope that GT FLEX ® GREEN can be a significant part of the solution, but we’re also wary – and weary – of “greenwashing” (intentionally vague or overstated claims about eco-friendliness), so let’s be clear here:
- GT FLEX ® GREEN has already passed independent testing indicating it is biodegradable under controlled compost conditions (also called “industrial composting”) as per ISO 17088-2021 standards.
- GT FLEX ® GREEN is still undergoing tests to evaluate whether it is also soil-compostable (i.e., “backyard compostable”).
There’s definitely an eco-friendliness difference between industrial and soil compostability. Some might argue that industrial composting is better than nothing, but there’s room to disagree, particularly because in many cases the waste never finds its way to an industrial composting facility.
In our case at least, as the manufacturer of the finished devices made with GT FLEX ® GREEN, we are able to ensure that the vast majority of material waste associated with these devices does end up at an appropriate composting facility.
In the meantime, we remain hopeful that the material will also meet the criteria for soil compostability. These tests are ongoing – fingers crossed!
Your Answer for Growing Patient Demand
Patients are expressing more and more concerns about the traditional plastic used in their dental devices – especially ones intended for long-term use.
I already remove plastic from my daily life (switched to metal water bottle and wax paper baggies), so why would I have plastic in my mouth at night that I’m grinding on?
Mac (GT Smiles Patient)
We hear things like that all the time. If you’re not already hearing it in your practice, you will – and soon.
GT FLEX ® GREEN is designed to give your practice an answer for these concerns.
And in providing a better option for your patients’ long-term dental health, GT FLEX ® GREEN also introduces a powerful new recurring revenue opportunity for your practice: subscription-based care.
Ready to Get Started?
Join the growing community of GT Smiles providers on the path beyond traditional plastic in dentistry.