An orthodontic aligner of the type that is deformable from its initial shape to a deformed shape when fitted upon a patients teeth in order to apply a load to the teeth to move the teeth to an orthodontically preferred position is made from a polymeric material that generates a continuing elastic return stress driving toward the initial shape after a substantial period of continuous deformation, such as longer than one day and up to or exceeding two weeks. Elastic stress loads applied to teeth over such durations cause greater remodeling of the bone adjacent to a tooths roots than is possible with known aligner materials.
