Abstract: A tool and method for seating an orthodontic aligner, unseating the aligner, or both. In one aspect, the tool comprises a handle portion and seating portion. The seating portion is connected to the handle portion. The seating portion comprises a rippled structure having the shape of a series of waves, the waves having a direction of propagation directed away from the handle portion. In a second aspect, a handle portion of the tool comprises a hook adjacent to a recess in the handle portion, the hook being configured to unseat an aligner. In a third aspect, the method comprises seating an aligner by holding a handle portion of the tool, positioning the seating portion between sets of teeth and repeatedly biting the seating portion. In a fourth aspect, the method comprises unseating an aligner by holding the rippled seating portion and using the hook to apply force to the aligner.