Figure 1. CAD & FDM process for digitally making of mandibular custom tray: (a) the standard mandibular edentulous plaster cast model; (b) the scanned plaster cast model data; (c) the model data was trimmed according to the coverage area of final impression; (d) the designed mandibular custom tray; (e) 3D printed custom tray; (f) the printed tray matched well with the plaster cast model.