José Ignacio Delgado Castaño, IMDEA MATERIALS
Transparent aligners have been the leading demand in orthodontics over the past decades. They do not compromise aesthetics, are more comfortable than traditional dental braces, and allow for better oral hygiene. Moreover, they are much less invasive.
However, ‘invisible’ aligners designed to gradually correct the position of teeth became the center of a troubling controversy before the summer. Despite their promising qualities, in March media outlets reported multiple complaints about their use, which led to a judicial investigation.
What lies behind the reported risks and damages? Is it possible to improve them to make them more effective and harmless?
The Low-Cost Treatment
The complaints are mostly not about the aligner itself, but about how they have been sold.
They have become trendy, which has led to more and more companies manufacturing and distributing them online at low prices. These companies design aligners based on photos of the mouth taken at home by the patient, sometimes without any supervision from an orthodontist, either in planning or during the treatment process.
The General Council of Dentists of Spain reported six of these brands to the Spanish Agency of Medicines and Medical Devices for dispensing a product directly to the public that is prescribed exclusively by dentists.
Just like any medical treatment, unsupervised use of aligners can be harmful to the user’s oral health and may even cause problems in other organs of the body.
The damages can range from treatments that do not deliver the expected results to bleeding, discomfort, loss of teeth, and even diseases related to the respiratory system, spine, or chronic migraines.
Not Always Better to Be Harder
But, setting aside the undeniable risk of unsupervised treatment, what about the aligner itself?
The main risk of using aligners is the force they exert on dental structures. The system must ‘push’ the teeth progressively to align them, and many of these aligners are made from materials that are too rigid. Rigidity causes them to apply excessive force during the first days of treatment, which is the main reason they cause notable discomfort initially. Later, the issue shifts: they deform quickly and stop exerting force, so many necessary dental movements for alignment are not completed.
So, we have a demanded treatment that needs improvement, and the way to do it is by renewing it.
In Search of New Materials
In research for invisible orthodontics, we seek a material that improves upon those used so far, that applies constant and sufficient forces on the teeth, and does not lose effectiveness.
The most important aspect of the treatment is that the tooth must be aligned correctly, neither too forward nor too backward. To achieve this, the aligner materials must accurately predict the movement of the teeth. They need to ensure a more controlled fluctuation between the initial and static forces. Only then can a continuous and effective treatment be guaranteed over time.
Currently, numerous companies and research centers are working to achieve this.
At the IMDEA Materials Institute, in collaboration with Secret Aligner, we are developing new materials with more predictable and defined strengths. These new materials maintain a balance between flexibility and deformation capacity to adapt to dental morphology. Additionally, they retain the ability to apply the necessary force for proper dental alignment throughout the process.
There are other advanced meta-materials, but they cannot yet be used in Europe.
The Goal?
After years of research, an innovative material is now available in the market that combines layers of various commonly used rigid materials with softer layers. This new material is composed of a derivative of polyethylene terephthalate (PET) and a thermoplastic polyurethane (TPU); however, unlike the traditionally used TPU in rigid orthodontic materials, this TPU is soft.
The new material is versatile, allows for more efficient treatments, with less pressure and, above all, more comfortable and painless for the patient. Currently, only a few companies produce different versions of this material in the US, China, and India, among other places, which are then marketed worldwide. However, it rarely reaches the Spanish market because no company has yet manufactured this type of multi-layer material in Europe.
European Push Towards Independence and Competitiveness
In the European Union, several companies are tackling its production to reduce dependence on external suppliers. Local production will have a significant impact: it will facilitate access for both leading companies and smaller laboratories struggling with raw material supplies.
When invisible dental aligners of this new era can finally be used generically in Europe, costs will be reduced, and a more personalized experience for patients and professionals will be offered.
Moreover, supply security and quality would be ensured, and in the future, the material and its production could be improved to become more competitive.
These new materials will transform the industry and offer more efficient and sustainable solutions.
Above all, they will make it possible for those using dental aligners to be more satisfied with the results, experience less pain, and likely see a reduced treatment time.
José Ignacio Delgado Castaño, Visiting Researcher, Biomaterials, IMDEA MATERIALS
The article was originally published in The Conversation. Read the original (content in Spanish).
