Steps 4-6


Figure 3: Retentive nailhead are blocked out during the fabrication of the detachable extension trays.

Step 4:  Block out the retentive nailheads present on the framework with a few drops of wax.  The nailheads are designated on the work authorization when the master cast is sent to the dental laboratory for framework fabrication.  Their purpose is to secure the impression tray(s) to the framework. (Fig. 3)

Step 5:  The impression tray(s) is/are made using light activated clear acrylic tray material that is placed over the framework and wax spacer. The borders of the impression tray conform to those of the wax spacer. Once the resin is cured, it should be removed and polished. Before the framework try-in appointment with the patient, the wax is removed from the master cast and the framework.

Step 6:  After the fit of the framework has been verified in the patient's mouth, the removable impression tray(s) is/are secured to the framework.  This is accomplished by placing a small amount of light-activated resin gel in the concavities created by the retentive nailheads on the framework.  As an alternative, a two-phase cyanoacrylate adhesive may be placed in the indentations in each impression tray to attach it to the framework.