Current implant techniques—an overview 13

Fig. 1-36. This radiograph clearly shows the relationship   Fig. 1-38. A wax interocclusal record of centric relation and

of the vent-plants to each other and to the abutment teeth.   plaster index are taken to complete the prosthesis.

Fig. 1-37. A, The castings are fitted and the interocclusal clearance checked by having the patient bite into centric occlusion. B, Copings are placed over the implant abutments and their clearance checked.

cated, it will be explained more fully in a later chapter.* In the case illustrated here, the helical burs create the implant sites.

The helical bur penetrates to the desired depth (Fig. 1-30) and is left in place as a guide for the second helical bur (Fig. 1-31). An x-ray is taken to check their positions (Fig. 1-32), and either bur is removed. The first vent-plant is then set in (Fig. 1-33) and its position x-rayed (Fig. 1-34).

The other vent-plant is then set in the same manner (Fig. 1-35), using x-rays to check that it is parallel (Fig. 1-36). Castings are fitted over the prepared natural tooth abutments and copings are placed over the implant abutments (Fig. 1-37). The necessary wax bite registrations and plaster indices are then taken for the fabrication of the final fixed partial denture (Fig. 1-38). The temporary acrylic splint is set in position, using temporary cement only inside the anterior abutment crowns (Fig. 1-39) .

Third visit. On the third—and final—visit the temporary splint is removed and the finished pros-thesis is equilibrated, radiographed, and cemented in permanently (Fig. 1-40) .

Tripod implants

The tripod implant is like the spiral-shaft and vent-plant implants only in that it must be set into bone. Otherwise it is totally unlike them in design.

*A simpler method of obtaining a bone core—using the trephine first to get the plug, then using the helical bur—will also be explained later.