Figure 2. Hand making process of mandibular custom tray: (a) the standard mandibular edentulous plaster cast model; (b) a slice of wax was baked soft to be paved on the cast model (top view); (c) the front view of the paved wax; (d) photo-curable resin is paved onto the surface of the wax, forming a “model-wax-tray” combination (top view); (e) The front view of the “model-wax-tray” combination; (f) A bar was added and the tray finally subjected to light curing for 10 min.