Department : Prostho
An individualized impression tray made from a cast recovered from primary impression. It is used in making a final impression. Special tray is constructed on the primary cast. As edentulous ridge show variations of shape and size (some have flattened ridges and other have bulky ridge). For this reason stock tray can fit the ridge only in an arbitrary manner, so special tray is constructed.
Materials used for construction of special tray
1. Cold cure acrylic resin or autopolymerizing acrylic resin (more common).
2. Visible light cured acrylic resin (VLC).
3. Shellac base plate.
4. Impression compound.
