When does a fixed dental prosthesis (FDP), which was cast in one piece, need to be sectioned?

Common reasons for a FDP not to fit in one piece are lack of parallelism between the abutments and distortion of the wax pattern during removal from the dies. In any of these cases, the framework may not fit in the prepared abutment teeth and must be sectioned between one of the connectors between the pontic and retainer to fit the two pieces individually, and a solder record must be made to solder the pieces.