The pressing technique is – apart from other shaping techniques like milling or slipping – an additional technique for the fabrication of all-ceramic restorations. Since the arrival of VITA PM9 in 2007 a press ceramic has been available that was developed out of the proven veneering ceramic VITA VM 9. It is particularly suited for the fabrication of inlays, onlays, veneers and anterior crowns with one or more surfaces and for the press-over technique on yttrium-stabilized zirconium oxide frameworks.
Basically, in press ceramics we distinguish between three different fabrication processes: the press-over technique for zirconium oxide frameworks (VITA In-Ceram YZ), the staining and the layering technique.
As an alternative to the classic ceramic veneering, using VITA PM 9 zirconium oxide frameworks can be pressed over (press-over technique). By means of this variant posterior crowns as well as anterior and posterior bridges with up to three pontics are possible. The fully anatomical wax modeling takes place directly on the zirconium oxide cap and is invested and pressed together with the cap. For the shade characterization and for glazing VITA AKZENT stains and glazing material as well as the stains and glazing of the VITA SHADING PASTE assortment.
With the staining technique the restoration is fully anatomically modeled in wax, invested and then pressed together with melted ceramic; this technique is comparable to gold casting. The pressing blank is processed and fitted to the die. To characterize or individualize the shade stain is applied and fixed by means of a ceramic firing.
The procedure in the layering technique is divided into two steps. The restoration is also first modeled fully anatomically but reduced before spruing. Similar to the veneering ceramic first a kind of framework is fabricated that is anatomically corrected by veneering ceramic – VITA VM 9 in the case of VITA PM 9 – after pressing and fitting..
However, PM9 is no framework material, only few individualizations are allowed!