Maxillary endosseous implant interventions 391

Fig. 10-16. An intraoral radiograph is taken with the template in the mouth to determine where to place the holes to accommodate the pins in circumventing the antral floor.

Fig. 10-18. The pin implants are driven through the template.

Fig. 10-17. After the holes are made, the two anterior crowns are cemented over the prepared teeth.

It was then possible to take an elastic impression of both vertical extensions of the template for fabricating the one-piece casting of the two-unit super-structure (Fig. 10-15).

The stone core was then tapped off the template, and the bridge was placed in the mouth with the superstructure and equilibrated. The superstructure was then removed, leaving the template attached to the two bicuspid crowns still in the mouth. It was imperative at this time to check that the scalloped template did not impinge on the fibromucosal tissue; it must fit passively. An x-ray was then taken in the sinus area to determine where the holes were to be made through the template in relation to the sinus (Fig. 10-16). The template was removed from the mouth and the holes drilled through it.

Hard cement was then placed inside the two bicuspid crowns and the prosthesis cemented into

Fig. 10-19. The ends are cut short so that they will not interfere with the insertion of the superstructure.

position over the two dried bicuspid teeth (Fig. 10-17).

The individual pin implants were slowly driven through the template in the various directions pre-determined by the radiographic interpretations (Fig. 10-18). The excess length of the pins was removed (Fig. 10-19). The pins were then locked together with acrylic and the two-unit superstructure was cemented over the template (Fig. 10-20). (A good method of cementation is to use oxyphosphate of zinc cement inside the anterior crown, which fits over the gold post in the template. The posterior crown should be filled with acrylic after roughening the inside of the crown and notching the acrylic core. In this manner, an acrylic-to-acrylic bond is achieved posteriorly.)

Once again, the bridge was checked for occlusion, and any excess cement was removed (Fig. 10-21).