The Empress crown is shaded with a die material injected internally which mimics the crown seated on the preparation. This die material comes in various shades, therefore the lab needs two shades: the shade of the completed preparation and the desired final shade. You can use the Ivoclar Stump (prep) shade guide for the preparation and the Ivoclar Chromascope shade guide for the final shade.

Preparation requirements are identical to other all ceramic techniques: 1.0-1.5 mm reduction on all axial walls, 2.0 mm incisal / occlusal reduction. and l.0 mm wide rounded shoulder or deep chamber margin. Veneer preparations would involve removal of 0.5 mm facial enamel finished to a small chamber at the gingival crest and extending around the promixal walls into, but not through, the contact area. Incisal margin should finish at the facial or lingual incisal line angle. In some cases the incisal margin can extend over to the lingual, but care must be taken not to go further than 1.0-2.0 mm and to allow for adequate thickness of porcelain.

After required preparation, take a standard crown and bridge impression. Use normal procedures with a good silicone. polyvinylsiloxane, rubber base, polyether; or hydrocolloid. Retraction cord should be used if indicated.

The tooth surface is treated with current dentinal adhesive procedures (etch / prime / bond) and the etched porcelain is silanated. The restoration is then seated with a dual-cure luting composite. (NOTE: You must use a resin cement - Hybrid cements will cause Empress to fail due to the expansion.)

If necessary, Empress restorations can be refined after seating. Use extra fine diamonds with water spray to "dress" or feather the porcelain margins into the tooth structure, or make any needed contour adjustments. These areas can be repolished using 3O-fluted carbines, felt wheels, and / or the Dialite polishing system.