What is the main characteristic of an edentulous tray compared to other trays?

An edentulous tray is specifically designed to accommodate the unique needs of patients who do not have any teeth. One of its primary characteristics is that it is not as deep as standard impression trays. This design is crucial because the absence of teeth changes the anatomy of the mouth, allowing for more efficient impressions of the soft tissues and the alveolar ridge without the complications that could arise from a deeper tray that could interfere with obtaining accurate impressions.

In the context of other options, while some trays may differ in material or depth, the notable distinction for edentulous trays hinges on their shallower depth, which aids in capturing the impression of the tissue contours more effectively. This ensures that the resulting impression is both comfortable for the patient and precise for dental procedures, such as the fitting of dentures.