Dual-arch, disposable applicator trays. Stable, nonflimsy foam design keeps fluoride in the tray and moisture out. Deep distal demand high walls improve patient comfort and inhibit overflow. Anatomical contours force fluoride into contact with tooth surfaces. Closed cell foam helps preclude fluoride absorption into the tray. Rounded arch and smooth ridge provide natural fit and comfort. Hide-a-hinge folds out of the way to help prevent gag reflex. Dual-hinge design saves time–but tray is easily separated for single-arch treatments.