Methods for making multilayer dental aligners
A multilayer sheet comprising first and second layers is provided. The first layer consists of a co-polyester. The second layer consists of a thermoplastic polyurethane elastomer having an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%. A mold is provided and the multilayer sheet is thermoformed over the mold to form a plurality of tooth-receiving cavities configured to receive and reposition a patient's teeth from a first arrangement toward a second arrangement. Excess material is trimmed from the thermoformed multilayer sheet to form a multilayer dental aligner.
1. A method of making a multilayer dental aligner, the method comprising:
providing a multilayer sheet comprising polymer layers, the polymer layers comprising:
a first layer consisting of a co-polyester; and
a second layer consisting of a thermoplastic polyurethane elastomer, wherein the thermoplastic polyurethane elastomer has an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%;
providing a mold;
thermoforming the multilayer sheet over the mold to form a plurality of tooth-receiving cavities configured to receive and reposition a patient's teeth from a first arrangement toward a second arrangement; and
trimming excess material from the thermoformed multilayer sheet to form the multilayer dental aligner.
2. The method of claim 1 , wherein the co-polyester has an elongation at break of greater than 70% and a tensile strength at yield of between about 4000 psi and 6500 psi.
3. The method of claim 1 , wherein the co-polyester has a flexural modulus greater than 150,000 psi.
4. The method of claim 1 , wherein the thermoplastic polyurethane elastomer has a flexural modulus greater than 35,000 psi.
5. The method of claim 1 , wherein the thermoplastic polyurethane elastomer has a compression set at about 70° C. of greater than 40% after 24 hours.
6. The method of claim 1 , wherein the first layer is coextruded with or laminated to a third layer.
7. The method of claim 1 , wherein the polymer layers of the multilayer sheet further comprises a third layer disposed between the first layer and the second layer.
8. The method of claim 1 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different co-polyester.
9. The method of claim 1 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different thermoplastic polyurethane elastomer with a hardness of about 60A to about 85D.
10. The method of claim 1 , wherein the first layer is thicker than the second layer.
11. A multilayer dental aligner for positioning a patient's teeth from a first arrangement toward a second arrangement, the multilayer dental aligner comprising:
a multilayer sheet comprising:
a first layer consisting of a co-polyester; and
a second layer consisting of a thermoplastic polyurethane elastomer, wherein the thermoplastic polyurethane elastomer has an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%;
wherein the multilayer sheet forms a plurality of tooth-receiving cavities configured to receive and reposition the patient's teeth from the first arrangement toward the second arrangement.
12. The multilayer dental aligner of claim 11 , wherein the co-polyester has an elongation at break of greater than 70% and a tensile strength at yield of between about 4000 psi and 6500 psi.
13. The multilayer dental aligner of claim 11 , wherein the co-polyester has a flexural modulus greater than 150,000 psi.
14. The multilayer dental aligner of claim 11 , wherein the thermoplastic polyurethane elastomer has a flexural modulus greater than 35,000 psi.
15. The multilayer dental aligner of claim 11 , wherein the thermoplastic polyurethane elastomer has a compression set at about 70° C. of greater than 40% after 24 hours.
16. The multilayer dental aligner of claim 11 , wherein the first layer is coextruded with or laminated to a third layer.
17. The multilayer dental aligner of claim 11 , wherein the polymer layers of the multilayer sheet further comprises a third layer disposed between the first layer and the second layer.
18. The multilayer dental aligner of claim 11 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different co-polyester.
19. The multilayer dental aligner of claim 11 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different thermoplastic polyurethane elastomer with a hardness of about 60A to about 85D.
20. The multilayer dental aligner of claim 11 , wherein the first layer is thicker than the second layer.
21. A multilayer dental aligner for positioning a patient's teeth from a first arrangement toward a second arrangement, the multilayer dental aligner comprising:
a multilayer sheet comprising:
a first layer containing a single polymer, wherein the single polymer of the first layer is a co-polyester; and
a second layer containing a single polymer, wherein the single polymer of the second layer is a thermoplastic polyurethane elastomer, wherein the second layer has an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%;
wherein the multilayer sheet forms a plurality of tooth-receiving cavities configured to receive and reposition the patient's teeth from the first arrangement toward the second arrangement.
22. The multilayer dental aligner of claim 21 , wherein the first layer has an elongation at break of greater than 70% and a tensile strength at yield of between about 4000 psi and 6500 psi.
23. The multilayer dental aligner of claim 21 , wherein the first layer has a flexural modulus greater than 150,000 psi.
24. The multilayer dental aligner of claim 21 , wherein the first second layer has a flexural modulus greater than 35,000 psi.
25. The multilayer dental aligner of claim 21 , wherein the first second layer has a compression set at about 70° C. of greater than 40% after 24 hours.
26. The multilayer dental aligner of claim 21 , wherein the first layer is coextruded with or laminated to a third layer.
27. The multilayer dental aligner of claim 21 , wherein the polymer layers of the multilayer sheet further comprises a third layer disposed between the first layer and the second layer.
28. The multilayer dental aligner of claim 21 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different co-polyester.
29. The multilayer dental aligner of claim 21 , wherein the polymer layers of the multilayer sheet further comprises a third layer, and wherein the third layer comprises a same or different thermoplastic polyurethane elastomer.
30. The multilayer dental aligner of claim 21 , wherein the first layer is thicker than the second layer.