A three-dimensional intraoral scanner includes: an outer body forming a trough, an outer surface of the outer body comprising a plastic material and an inner surface of the outer body at the trough including a transparent or translucent material, the trough being configured to fit around a row of a patient's teeth； and a sled within the outer body and configured to move along the trough, the sled including a plurality of ultrasonic sensors and a plurality of optical sensors configured to image the patient's mouth.
