Current implant techniques—an overview 7

When the first implant is successfully in place, the "guide" tap is removed. The second implant is installed in the same way, carefully setting it parallel to the first one and to the anterior abutment teeth (Fig. 1-15). In this procedure it is important that there be adequate occlusal space between the implant posts and the opposing teeth to permit the installation of an acrylic crown or porcelain crown casting.

Gold copings are fitted over the implant abutments (Fig. 1-16). These gold copings should be fabricated prior to implant insertion and should be interchangeable with all of the implant posts. They should also fit the posts rather loosely; if not, their removal might be difficult, because the implant posts are rectangular, not tapered, as are teeth that have been prepared for jacket crowns. The veneer castings, which have been prepared beforehand from the impressions and bites taken at the time of the patient's first visit, are then fitted over the anterior abutments.

A wax or stone bite is taken (Fig. 1-17) and a plaster index is made. This index should contain the veneer crown castings as well as the implant copings (Fig. 1-18). Laboratory procedures are facilitated if brass posts of the same diameter as the implant posts are placed into the gold copings set in the plaster index. The master stone model is then poured (Fig. 1-19).

The occlusal surfaces of the implant posts are marked with an indelible pencil, and the acrylic splint that had been prepared immediately after the first visit is placed into position. The pencil marks offset onto the splint, and holes for the implant posts are then drilled into the splint at the marks.

Fig. 1-16. A, Interchangeable gold copings are placed over the protruding implant shafts and veneer castings are fitted over the bicuspid preparations. (In this case the veneer crowns that the patient had made originally were utilized for the anterior abutments, and therefore the original tooth preparations could not be reprepared.) There should be no occlusal interferences. B, Roentgenogram reveals the restorations in place.

Fig. 1-17. A wax interocclusal record of centric relation is taken.

Fig. 1-18. A plaster index is used to pick up the castings and copings.