An impression technique to make a new master cast for an existing removable partial denture

When the master cast for a removable partial denture is lost and a well-fitting framework remains, it may be necessary to replace the master cast. A two-step impression procedure is described that combines the altered-cast technique and the use of a modified disposable tray. Finger pressure is maintained on the major connector throughout the making of both impressions, to prevent framework movement and loss of contact with prepared rest seats.