Ivoclar Vivadent IPS e.max ZirPress - Manual (Page 50)

50
Sprueing, Investing
Basically, the sprueing guidelines on pages 21ff apply.
Always attach the sprues in the direction of flow of the ceramic from the basal and at the thickest part of the wax-up so
that smooth flowing of the viscous ceramic during pressing is enabled. Depending on the number and size of the objects
to be invested, either the 100 g, 200 g, or 300 g IPS Investment Ring System is selected.
For the processing steps preheating, pressing, divesting, removing the reaction layer and separating the restora-
tion, please refer to the pages 25–30.
… and secure with wax on the ring base. Provide sprues for the gingival parts at the thickest part…
Please note:
– Blast the restoration with Al
2
O
3
(type 100) at 1-2 bar (15-30 psi) pressure after removing the reaction layer using
IPS e.max Press Invex Liquid.
– Carefully blast the non-pressed areas (exposed ZirLiner) in order to avoid complete removal of the ZirLiner.
Finishing
It is of critical importance to use the correct grinding
instruments for finishing and adjusting high-strength
glass-ceramics. If unsuitable grinding instruments
are used, chipping of the edges and local over-
heating may occur (please observe the Ivoclar
Vivadent Flow Chart ”Recommended grinding tools
for PS e.max glass-ceramics”.
Observe the following procedure for finishing
IPS e.max ZirPress Gingiva:
– Even though adjustment by grinding of pressed
IPS e.max ZirPress restorations is possible, it
should be kept to a minimum.
– Separate the sprues with a fine diamond disk
under permanent water cooling of the cutting
area.
– Overheating of the ceramic must be avoided. Low speed and light pressure is recommended.
– Smooth out the attachment points of the sprues.
– Design surface textures.
– To clean the restoration, briefly blast with Al
2
O
3
at 1 bar (15 psi) pressure and clean with the steam jet.
– Some blasting devices may require different pressure settings to accomplish this procedure.
Restoration with pressed gingival portions made of IPS e.max ZirPress Gingiva after divesting.