Ivoclar Vivadent IPS e.max Ceram - Manual (Page 7)

7
Firing of lithium disilicate-supported restorations
– Use the honey-combed firing tray and the corresponding support pins to fire the restorations.
– Do not use ceramic pins, since they may stick to the restoration.
– The processing temperatures must be observed. Increasing the firing temperature will result in severe vitrification
between the framework and the veneering ceramic, which may lead to crack formation later on. Reducing the firing
temperature results in the ceramic being underfired, rendering it very brittle, which may ultimately lead to delamination.
– The parameters listed in the Instructions for Use apply to Ivoclar Vivadent furnaces (temperature tolerance ± 10 ºC/18 °F).
– If furnaces other than those from Ivoclar Vivadent are used, temperature adjustments may be necessary.
Firing of zirconium oxide-supported restorations
In order to obtain optimum firing results for IPS e.max Ceram, the following points have to be observed:
– In order to ensure an even thickness of the veneer, the zirconium oxide framework must be designed in such a way that
it supports the cusps. Depending on the clinical situation, the results are different wall thicknesses and dimensions of
the framework.
– Since ZrO
2
is a poor heat conductor compared to other framework materials, a low temperature increase rate t
➚ is
required. This ensures even heat distribution in the bonding area between the framework and the veneer as well as the
outer surfaces of the restoration even with different framework thicknesses. In this way, an optimum bond as well as
even sintering of the layering materials is achieved.
– During cooling of the restorations after firing, stress occurs as a result of the different cooling speeds at the outside and
within the material. With long-term cooling L for the "final firing cycle" this stress can be reduced and the risk of
delamination minimized, particularly in ZrO
2
-supported restorations.
Notes on cooling after completion of the firing program
In order to ensure "smooth" cooling of the restoration after firing, please observe the following notes:
– Wait for the acoustic signal or optical indication of the furnace at the end of the firing cycle before the firing tray with
the fired objects is removed.
– Do not touch the hot objects with metal tongs.
– Allow the objects to cool to room temperature in a place protected from draft.
– Do not blast or quench the objects.