• Prep Requirements

BruxZir® Solid Zirconia

Anterior full-coverage crowns require a chamfer with 1.5 mm facial reduction, 1.5 mm lingual contact clearance, 1.5 mm incisal reduction 1.25 mm reduction at the gingival margin with rounded internal line angles; or a shoulder with 1 mm lingual reduction, 2 mm incisal reduction, 1.5 mm labial reduction, 1 mm 360° rounded shoulder.

Posterior full-coverage crowns require a chamfer margin with 2 mm occlusal reduction, 1.5 mm buccal and lingual reduction with rounded internal line angles; or a shoulder with 2 mm occlusal reduction, 1.5 mm buccal and lingual reduction and 1.25 mm gingival margin reduction with rounded internal line angles.

Chamfer Margins - Correct preparation of the chamfer margins interproximally allows the appropriate bulk of porcelain.

IPS e.max®

Anterior full-coverage crowns require a chamfer or shoulder margin. A circular shoulder is prepared with rounded inner edges or a chamfer at an angle of 10-30 degrees: the width of the shoulder/chamfer is approx. 1 mm. Facial reduction is 1.5-2.0 mm; 1.0-1.5 mm lingual contact clearance. Incisal reduction is 1.5-2 mm with rounded internal line angles, and an incisal edge at least 1mm wide to permit optimum milling of the incisal edge during CAD/CAM processing.

Posterior full-coverage crown requires a chamfer or shoulder margin. A circular shoulder is prepared with rounded inner edges or a chamfer at an angle of 10-30°: the width of the shoulder/chamfer is approx. 1 mm. Occlusal reduction is 1.5-2 mm: axial reduction (buccal, lingual and interproximal) is 1.5 mm with rounded internal line angles.

IPS Empress®

Anterior full-coverage crowns require a chamfer with 1.5-2 mm facial reduction, 1-1.5 mm lingual contact clearance, 1.5-2 mm incisal reduction, 1-1.5 mm reduction at the gingival margin with rounded internal line angles; or a shoulder with 1 mm lingual reduction, 2 mm incisal reduction, 1.5 mm labial reduction, 1 mm 360° rounded shoulder.

Posterior full-coverage crowns require a chamfer margin with 1.5-2 mm occlusal reduction, 1.5 mm buccal and lingual reduction with rounded internal line angles; or a shoulder with 1.5- 2.0 mm occlusal reduction, 1.5 mm buccal and lingual reduction and 1-1.5 mm gingival margin reduction with rounded internal line angles.

Inlays and onlays require 1.5-2 mm isthmus width, 1-1.5 mm wide gingival floor with rounded internal line angles and butt joint margins.

Veneers require a uniform preparation and lingual reduction to increase strength. A medium-grit round-ended diamond is used to join the depth cut grooves to establish a uniform preparation and porcelain thickness of at least 1 mm. The diamond is angled to eliminate undercuts and establish a butt joint on the lingual aspect of the preparation. The incisal edge should be rounded to eliminate sharp line angles.

Chamfer Margins - Correct preparation of the chamfer margins interproximally allows the appropriate bulk of porcelain.

A Slice Preparation - This technique enables the ceramist to close the space and avoid unnatural lingual contours.

Lava™ Crowns & Bridges

Anterior full-coverage crowns require a chamfer with 1.5 to 2 mm facial reduction, 1 to 1.5 mm lingual contact clearance, 1.5 to 2 mm incisal reduction, 1 to 1.5 mm reduction at the gingival margin with rounded internal line angles; or a shoulder with 1 mm lingual reduction, 2 mm incisal reduction, 1.5 mm labial reduction, 1 mm 360 degree rounded shoulder.

Posterior full-coverage crowns require a chamfer margin with 1.5 to 2 mm occlusal reduction, 1.5 mm buccal and lingual reduction with rounded internal line angles; or a shoulder with 1.5 to 2 mm occlusal reduction, 1.5 mm buccal and lingual reduction and 1 to 1.5 mm gingival margin reduction with rounded internal line angles.

Chamfer Margins: Correct preparation of the chamfer margins interproximally allows the appropriate bulk of porcelain. In addition, Lava has a digital wax-up to bulk up the zirconia substructure when extra support for the ceramic is needed.

A Slice Preparation: This technique enables the ceramist to close the space and avoid unnatural lingual contours.

Premise Indirect™

Preparation requirements for Premise Indirect restorations are similar to that of all-ceramic restorations, requiring rounded internal line angles, shoulder margins of at least 1 mm and an occlusal clearance of at least 1.5 — 2 mm.

Prismatik CZ™

Anterior full-coverage crowns require a chamfer with 1.5 mm facial reduction, 1.5 mm lingual contact clearance, 1.5 mm incisal reduction 1.25 mm reduction at the gingival margin with rounded internal line angles; or a shoulder with 1 mm lingual reduction, 2 mm incisal reduction, 1.5 mm labial reduction, 1 mm 360° rounded shoulder.