Ivoclar Vivadent IPS Empress CAD Chairside - de-en-es-it-ru - Manual (Page 82)

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Cut-back technique
Before the cut-back is carried out, the following points must be observed:
– Use only suitable, fine-grained (grain size < 60 µm), ceramic-bonded grinding instruments or diamonds at a speed of up
to 20,000 rpm and little pressure.
– Carefully finish the restoration margins using rubber and silicone polishers (Speed: <10,000 rpm)
– Overheating the glass-ceramic must be prevented.
– If the wrong grinding instruments are used, marginal chipping and local overheating may occur.
– Smooth out attachment point of the holder and take the proximal contact points into account.
– Before the cut-back the veneer or anterior crown should correspond with the final tooth shape.
– The incisal length must be exactly defined and the occluding surfaces taken into account.
– A palatal silicone key is used as a reference for the cut-back.
– The silicone key should slightly embrace the incisal edge.
Please see page 27 for information about the
fabrication of a control die using IPS Natural Die
Material.
Before the cut-back the veneer or anterior crown should correspond with the final tooth shape. Fabricate a palatal silicone key.
The control die made of IPS Natural Die Material is the optimum basis for sound
shade reproduction.