When patients leave out their SureSmile aligners for too long, the teeth will begin to shift back into their original positions. Orthodontic treatment can move the teeth rather quickly by applying pressure. In a similar fashion, a reduction in that pressure will have the opposite effect. In some instances, your aligners may not fit correctly if you try to place them back over your teeth. One of the benefits of SureSmile is that the aligners can be removed while eating but they do need to be replaced as soon as possible.