Dentsply Sirona Biosil f Mode D'emploi page 7

6 Step-by-Step instructions
6.1 Sprues
2 – 4 sprues – depending on the size of the frame work
should be attached to each object. In order to facilitate
flow of way and controlled solidification, wax sprue wire
with a diameter of 3 – 4 mm should be attached to the
thickest points of the casting tapering. The length of the
sprues must be determined individually by the selection
and the position of the sprue former.
6.2 Investing
®
Apply a thin coat of Waxit wetting agent to the wax
®
object or spray with Waxit and then blow it dry carefully
(do not use compressed air). Invest the pattern with
® ®
Optivest or Biosint investment. Observe the working
instructions of the investment that is used. A fine invest-
ment can be used. However, it is not required if a fine-
®
grain investment compound like e.g. Optivest is used.
6.3 Preheating
Preheat slowly with the suction system activated. Adhere
to the heating rates and holding times given by the
manufacturer of the respective investment. After the final
temperature of 1000 °C has been reached, preheat the
casting ring for 60 min. In the case of particularly filigree
constructions the preheating temperature must be raised
to 1050 °C. The holding time must be extended corre-
spondingly, if a larger number of casting rings is used.
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