Methods for making multilayer dental aligners

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.

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.