364 Theories and techniques of oral implantology

On the first visit, the pontic was prepared for a full crown preparation, making sure not to reduce the mesial interproximal surface too much so as not to weaken the solder joint (Fig. 9-97). A rubber base impression of the preparation and edentulous area, a bite, and an opposing jaw alginate impression were taken.

On the second visit, the veneer casting was tried over the pontic preparation and adjusted. The implants were set into sites determined by radiographs taken at the previous visit. In this case, a single triplant was used (Fig. 9-98). Its pins were built up with acrylic, and then the acrylic core was prepared for a full crown restoration. (When post implants are used, interchangeable gold copings are fitted over the implant posts and a wax bite and plaster index are taken. These should cover the natural abutment tooth as well as the copings over the implant shafts.)

An impression was taken with a soft impression material. (Plaster should be avoided because it might leak underneath the acrylic core, wedging between it and the soft tissue and causing dislodgment when the hardened plaster is removed.)

The temporary acrylic splint was fitted over the abutments and adjusted. It was affixed with temporary cement, and care was taken not to place any inside that portion of the splint that covered the implants. The splint was fabricated from the same master stone model that was used for fabricating the veneer casting.

On the third and final visit, the completed pros-thesis was tried in the mouth and radiographed (Fig. 9-99). Any further adjustments were made, and then the bridge was cemented with hard cement (Fig. 9-100).

This method is not only useful where cantilevered

Fig. 9-97. The cantilevered second bicuspid is prepared for a full crown preparation, making sure not to sever its mesioproximal solder joint. An acrylic core supporting a triplant is seen posteriorly. (From Linkow, L. I.: The versatility of implant interventions, Dent. Concepts 2:5-17, 1966.)

Fig. 9-99. The completed partial bridge is cemented. (From Linkow, L. I.: The versatility of implant interventions, Dent. Concepts 2:5-17, 1966.)

Fig. 9-98. The three pins are driven deep into the bone and diverge from each other at almost 45-degree angles. (From Linkow, L. I.: The versatility of implant interventions, Dent. Concepts 2:5-17, 1966.)

Fig. 9-100. The postoperative radiograph. (From Linkow, L. I.: The versatility of implant interventions, Dent. Concepts 2:5-17, 1966.)