Steps 10-12

Step 10:  A trial impression is made using irreversible hydrocolloid.  This impression is made to ensure that there is no impingement of the border-molded tray on the underlying soft tissue.  If any pressure spots are noted, they should be removed.

Step 11:  The final impression can be made with a variety of materials.  The two most commonly used are polysulfide rubber (64%) and ZnOE paste (22%).⁶  The edentulous areas should be dried. Care should be taken to prevent any of the impression material from getting trapped under the rest when the framework is positioned back on the abutment teeth.¹¹  After the framework has been properly positioned, it should be held firmly in place with the operator's fingers pressing on the rests.The patient is then instructed to close until light contact is made with the dentist's fingers.  This will permit the masticatory muscles to relax.  When the impression material is set, the framework is removed from the mouth and checked for discrepancies.  Any impression material that is on the tissue surface of the major connector should be trimmed to correspond to the internal finish line.

Step 12:  A wax block is placed on the occlusal surface of the impression tray.  It should be trimmed so that two millimeters of space exist between the wax and the opposing occlusal surfaces.  A recording medium is placed on the wax, and the framework is repositioned on the abutment teeth.  The patient is then guided to closure in the desired jaw relationship. (Fig 4)  After the framework is removed, a face-bow transfer recording is made, and the artificial teeth are selected.