Maxillary endosseous implant interventions 427

Fig. 10-154. The two crowns were cemented over the two gold copings and then the pin implants were drilled through the openings in the template into the bone.

Fig. 10-155. The pins were fastened to one another using acrylic liquid and powder with the brush-on technique.

Fig. 10-156. A fast-setting stone impression tray was then made to fit over the restoration.

soft wax was placed over it for a wax bite. A plaster index of the entire maxilla, including the veneer castings, was taken.

From the articulated master stone casts, a horse-shoe template was waxed, cast, and then soldered to the polished molar castings. Acrylic facings were processed to the buccal surfaces of the two posterior castings. Anteriorly four vertical pontics, or pivots with internal threadings, were included in the template so that the removable prosthesis could be screwed into position if desired and could be re-moved only by the dentist (Fig. 10-152).

At the next visit, the template with the soldered veneer crowns was tried in the mouth and radio-graphed. It was then removed, and holes were drilled through the template in the areas where the pin implants were to be driven (Fig. 10-153).

After making sure that the two posterior crowns were in proper occlusion, the operator placed hard

Fig. 10-157. A rubber base impression was taken of the entire maxillary template with the built-up acrylic cores, using the stone tray.

cement inside them and cemented them over the two copings. All excess cement was removed when it hardened.

Carefully checking with intermittent x-rays, the operator slowly drove pin implants through the template at various angles to avoid the sinus and nasal vestibulum (Fig. 10-154). To avoid occlusal interference, the excess length of the pins was cut off. The terminating ends were then notched with a fissure bur to aid retention when being fused with cold cure acrylic (Fig. 10-155). The acrylic cores, when hardened, were trimmed, prepared, and polished. They were parallel to the anterior gold posts on the template.

Again, a stone model tray was fabricated directly in the mouth, trimmed, and made more retentive by drilling holes across its tissue-bearing surface (Fig. 10-156). It was then painted with Permalastic adhesive to make the rubber base im-