372 Theories and techniques of oral implantology

Fig. 9-124. An immediate postoperative roentgenogram reveals the four internally threaded implants, the three atypically shaped copings, and a triplant and spiral-shaft implant in the maxilla.

Fig. 9-125. Same patient as in Fig. 9-124 as viewed from the other side, showing the mesostructures in position over the implants.

Fig. 9-126. The lateral plate x-ray shows the superstructure screwed into both mesostructures. (From Linkow, L. I.: Internally threaded endosseous implants, Dent. Concepts 10: 16-20, 1967.)

balance the four remaining teeth : the right central, lateral, cuspid, and first bicuspid. All were prepared for full crown restorations (Fig. 9-127).

To insert the vent-plants, round burs were drilled through the fibromucosal tissue and into the bone (Fig. 9-128). These were followed with the varying sizes of helical burs (Fig. 9-129). The vent-plants were then self-tapped into the deep bone structures (Fig. 9-130) .

Impressions were taken of the prepared teeth and implant shafts, and a soldered gold coping splint was cast. A one-piece gold superstructure casting to fit over the copings was processed with it in the denture (Fig. 9-131) .

The structure was then cemented over the pre-pared teeth and implant shafts (Fig. 9-132) and the denture fitted and balanced (Fig. 9-133). The radio-graph of the superstructure over the copings reveals the extremely long vent-plants used in this case (Fig. 9-134). Because very few nerve endings exist in the anterior region of the mandible, long post type implants were possible.

THE EDENTULOUS MANDIBLE

There are several considerations and alternatives in planning a full arch fixed denture for a