328 Theories and techniques of oral implantology

of pencil on the soft tissues as a guide for positioning the implant (Fig. 8-52).

The implant, a vent-plant, was then placed in the ratchet (Fig. 8-53). To keep the head of the ratchet away from the occlusal surfaces of the neigh-boring teeth, an unusually long prolongator was used (Fig. 8-54). The implant was inserted (Fig. 8-55) and the length of the protruding shaft checked for occlusal clearance by having the patient bite in centric occlusion (Fig. 8-56).

An interchangeable, serrated gold coping was placed over the implant post (Fig. 8-57). A loose mix of acrylic was placed inside the hollow ground pontic, the bridge seated, and the acrylic allowed to harden. The bridge was removed, with the gold coping as an integral part of the restoration (Fig. 8-58) . The excess acrylic was trimmed and polished. The bridge was cemented over the bicuspid tooth and implant post with hard cement (Fig. 8-59), and a final operative radiograph taken (Fig. 8-60).

Fig. 8-60. The postoperative radiograph.

Fig. 8-62. A, The second premolar was prepared for full coverage and a two-unit gold occlusal acrylic veneer splint was prefabricated. B, The two-unit splint as seen on the master model.

Fig. 8-61. A missing maxillary first premolar is seen in the mouth of a young actress who did not want her cuspid tooth touched.

Fig. 8-63. A specially sized twist drill is used to trephine the bone.