324 Theories and techniques of oral implantology

Fig. 8-41. A mesiocclusal inlay preparation is made within the confines of a previously existing gold inlay on a maxillary second bicuspid tooth.

Fig. 8-42. A prefabricated acrylic-fused-to-gold thimble crown with the attached inlay is seen on the model.

The lumen of the tissue-bearing surface of the implant crown was marked with indelible pencil and the splint was then replaced in the mouth. The lumen was slightly larger than the implant shaft to compensate for any errors in technique. Using as a guide the circle of indelible pencil transferred to the soft tissue crest, the implant was then inserted (Fig. 8-43). When the implant had been seated to its predetermined depth in the bone, the prosthesis was again tried in the mouth (Fig. 8-44). All necessary adjustments were made to ensure a passable fit, and the restoration was removed. The line angles of the protruding implant shaft were then notched horizontally all along the shaft's length and on all four sides. The inside of the crown restoration was also notched for retentive purposes. Oxyphosphate of zinc cement was used for cementation of the inlay, and

Fig. 8-43. A, After the bone is trephined with various burs, a self-tapping vent-plant is fitted into the prolongator, which connects it to the ratchet. B, The protruding post extending from the fibromucosal tissue should not be longer than 3 or 4 mm. so that it will not interfere with the fit of the restoration.

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Fig. 8-44. The crown is fitted over the implant. The thumb and forefinger are holding the inlay restoration, which ex-tends posteriorly from the gold thimble underneath the acrylic restoration.