The lithium disilicate blocks of IPS e.max® are composed of a unique crystalline, monolithic structure, giving this material its unbelievable esthetics, strength and durability. At Treasure Dental Studio, we press our e.max, ensuring optimum flexural strength of 400 MPa and outstanding marginal fit. With less fracturing and fewer chairside adjustments, IPS e.max Press is ideal for thin veneers and anterior bridges, and is a cost- and time-saving option for your practice.
IPS e.max® should not be used on patients with malfunctional occlusion such as bruxers or clenchers. IPS e.max® should not be used as abutments for cast partials. IPS e.max® should not be used in situations when preparation requirements cannot be achieved. IPS e.max® is not indicated for Maryland-type bridges.
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°: the width of the shoulder/chamfer is approx. 1 mm. Facial reduction is 1.5 – 2 mm; 1 – 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.
For greatest strength, and where preparation allows for dry field (supra-gingiva margins), it is recommended to use adhesive bonding, such as VarioLink II (Ivoclar Vivadent) or similar dual cure materials (Insure, Cosmedent; Nexus, Kerr; Choice, Bisco, Inc.; Lute-It, Pentron).
For areas subgingival, or when a dry field cannot be achieved, Ivoclar Vivadent recommends a hybrid glass ionomer cement system with less than 0.5 percent expansion. (NOTE: Resin-reinforced glass ionomers (Advance, Vitremer) are not indicated for any all-ceramic restoration.)
Some recommended resin cements:
- Vivaglass (Ivoclar Vivadent)
- GC Fuji (GC America)
- Ketec Cem (3M ESPE)
- Panavia F (J. Morita)
- C&B Metabond
- Variolink (Ivoclar Vivadent)
If adjustment is required on the ceramic, ALWAYS CEMENT OR BOND INTO PLACE BEFORE PROCEEDING, then use a fine diamond with water to keep the crown cool. To contour the crown, polish with a porcelain polishing wheel ( Brassler, Shofu and Vident) and diamond polishing paste.
Caution: Do NOT attempt to fire porcelain. IPS e.max® ceramic requires specific stains and glaze, as well as precisely calibrated ovens at specific temperatures and vacuum settings.For best results, return crown for re-glaze firing to lab.