430 Theories and techniques of oral implantology

The pin implants were driven through the template and the superstructure fitted over the protruding pins (Fig. 10-163). In such a situation, if the superstructure does not seat, the protruding portions of the pins must either be bent within the peripheral margins of the template or be cut shorter.

When the superstructure fitted with no impingement from the pins, the bridge was removed and the pins fused to one another with acrylic (Fig. 10-164). While the acrylic was still soft, the super-structure was fitted into position. Any impingement was caused by the soft acrylic, which was easily re-moved. When the acrylic hardened, the superstructure was cemented into position. Acrylic was used

Fig. 10-165. The superstructure is cemented over the template with hard cement.

inside the crowns covering the acrylic cores, and oxyphosphate of zinc cement was used inside the crown that covered the gold coping (Fig. 10-165). Fig. 10-166 is a Panorex of the completed case.

Case 18

A roundhouse restoration using a three-part prosthesis, template, and a triplant

Sometimes, because of inconvenience or inability to parallel all the teeth in an arch as a result of their original positions, it may be beneficial to fabricate the bridgework in three separate sections rather than one. This case illustrates such a situation.

The remaining teeth were prepared (Fig. 10-167) and copings cast (Fig. 10-168). A wax interocclusal record of centric relation was made. An alginate (irreversible hydrocolloid) impression of the lower arch was taken, as well as a maxillary plaster index picking up all of the copings (Fig. 10-169).

From these records the prosthesis was fabricated in three sections (Fig. 10-170). Connecting with the right central and left central and lateral incisors were two copings with posts going into the two corresponding roots (Fig. 10-171) . The two unilateral right and left posterior bridges were made to fit over the gold copings anteriorly. The right bridge had a molar crown supported by a molar tooth while the left bridge contained the template for the edentulous area (Fig. 10-172).

The anterior quadrant was cemented into posi-

Fig. 10-166. A postoperative x-ray showing a one-dimensional tripodial spread.