For testing purposes, we milled out many objects, with different indication:
– Step preparation for press
– Tangential preparation for metal frameworks
– Screw retained crowns for implant/ti-base
The end result is anticipated, highly accurate and precise.
After removing the objects from the blank, we follow the recommended procedure from manufacturer of the investment material, in this case Ivoclar’s IPS Press Vest Premium, speed investment material.
It is very important to observe the recommended distance of at least 10mm between the wax object and silicone ring wall.
In our lab, in cases like this with more than 3 objects we always use the 200gr. investment ring to insure that the procedure of preheating and pressing is successful.
For 200gr ring, we used the following mixing ratio:
– 200gr powder with 36ml liquid and 16 ml distilled water
After mixing and pouring the investment, we wait for 20min for the investment to set and then we place the investment ring in preheated furnace at 850C to burn for 1 hour.
As you can see on the following picture, we did not have any problems with cracking, during the pressing process.
Sharp edges that we had from the milling process remaining the same after pressing.
Results from three consecutive pressing processes, after sandblasting with Cobra 110um:
Milling machine used: AG Ceramill motion II
Press furnace: Ivoclar EP 3000
Press ingots: Emax MO-0, LT- BL1, Impulse Value 1
Further information: Products for digital workflows