The fit of Procera titanium crowns. An in vitro and clinical study.

In contrast to conventional casting methods for the production of a metallic crown the Procera process is based on precision machine duplication of models combined with spark erosion of the metal frame. Some of the steps in the manual handling procedure are thereby excluded. The present study evaluated, by means of a replica technique, the fit or adaptation of Procera titanium crowns to the stone die and in vivo to the tooth before cementation. For any combination, the marginal adaptation was superior to and significantly better than the occlusal areas and axial surfaces, respectively. In addition, the crowns had a significantly better fit to the stone die than to the tooth. The marginal discrepancy was approximately 60 microns in vitro and 70 microns in vivo, with a range of 3-205 microns.