Steps 1-3

Step 1:  After the RPD framework is received from the dental laboratory, it should be evaluated for fit.Metal projections and sharp edges should be adjusted.  Before returning the framework to the master cast, all undercut areas on the abutment teeth should be removed with a sharp knife.  This will facilitate the seating and removal of the framework with minimal effort and lessen the possibility of clasp distortion or breakage of teeth on the master cast.

Step 2:  The outline for the wax spacer is drawn on the edentulous area(s) of the master cast so that the wax border is two millimeters inside the anticipated peripheral extensions of the denture base.The spacer should stop at the internal finish line of the framework.


Figure 2: Wax spacer in relation to RPD borders when using the selective pressure technique.
Step 3:  A single layer of base plate wax is placed on the master cast and trimmed to conform to the pencil lines.The framework is warmed and reseated on the master cast ensuring that all of the rests are completely seated in the rest seats.  If any wax has melted and covered the denture base retentive nailheads on the framework, it should be thoroughly removed.The wax spacer provides for a uniform thickness of impression material and prevents contact of the acrylic tray(s) with the soft tissue in the edentulous space.  If a selected pressure technique is used, the buccal shelf is kept free of the wax spacer. (Fig. 2)