Subperiosteal implants 549

Fig. 12-42. The Marziani-designed tantalum subperiosteal implant.

holes in the model. These pins secure the "cutout" during the pressing procedure and maintain the surfaces around the holes through which the abutments will be inserted.

The meshwork is carefully molded to the stone model, and the abutment posts are affixed parallel to one another either by welding or by screws. The implant is once more cleansed with carbon tetra-chloride and a 5% nitric acid solution and then sterilized.

Finally, the implant is positioned over the ex-posed mandibular bone (Fig. 12-42). For immediate fixation, a few screws are passed through the implant and into the bone in the areas of the external oblique ridges and symphysis.

The tissues are sutured over the implant and the prefabricated lower denture is hollowed out and fitted to the four abutments with the use of fast-setting acrylic. The case is occluded and balanced out. Roentgenograms are taken periodically to analyze the situation (Fig. 12-43) .

Unilateral implantations following slightly modified procedures are shown in Fig. 12-44.

UNILATERAL SUBPERIOSTEAL IMPLANTS

Each unilateral implant of American design inserted by Linkow prior to 1955 had to be removed.

Fig. 12-43. A posteroanterior roentgenogram showing a maxillary and mandibular tantalum subperiosteal implant.

Fig. 12-44. Two different unilateral tantalum type subperiosteal implants.