CPC A61C 7/08 (2013.01) [A61C 7/002 (2013.01); Y10T 29/4957 (2015.01); Y10T 83/04 (2015.04); Y10T 83/0586 (2015.04)] | 26 Claims |
1. An aligner comprising:
a polymeric shell comprising:
a plurality of tooth-receiving cavities shaped to receive a patient's teeth and reposition the patient's teeth from a first arrangement toward a second arrangement;
an interior layer comprising a first stiffness; and
an exterior layer comprising a second stiffness greater than the first stiffness, wherein the exterior layer comprises a discontinuity formed therein, and the discontinuity comprises a cut,
wherein, when the aligner is worn on the patient's teeth, the cut is stretched by placement of the aligner on the patient's teeth, the interior layer interacts with the cut by resisting the stretching, and the interaction between the interior layer and the cut imparts one or more forces to facilitate repositioning of the patient's teeth from the first arrangement toward the second arrangement.
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