I own and operate a small dental lab and purchased the Form 1 printer with hopes of printing CAD-designed dental restorations for lost wax casting of metal, and lithium disilicate (Emax) glass pressing processes. Today I made a few prints of dental prosthetic restorations, invested one of them, burned it out and pressed it in lithium disilicate (Emax by Ivoclar) using a specialized glass-pressing oven. It worked!
Here are the specifics:
- Printed several crowns (teeth) on a small corner of the platform.
- .05 mm Grey material setting (Decent surface texture when completed).
- One hour total print time.
- Cleaned the teeth in alcohol and light cured them using a Dentsply "Triad 2000" curing unit (5 minutes).
- Checked the crown fit to the master die and sealed the margin using margin wax to achieve a perfect fit.
- Invested one crown using Microstar HS Investment. 14 minute bench set time, then straight into an oven preheated to 1562 degrees F.
- 1 hour burnout.
- Pressed 1 Emax (lithium disilicate) ingot in a Zubler 300e pressing furnace.
- Sand blasted the tooth out of the investment after 30 minutes cooling time.
- Cheered loudly!
Check out the results. I'm very encouraged by this first test. My normal investing, burnout, pressing procedure seemed to work perfectly. This process is picky about ash residue left in the investment during burnout as it leaves dark speckles in the glass. There doesn't appear to be any discoloration of the glass. I use this same investment for my metal castings, so there should be no problems there. There was a lot of dark smoke as the resin ignited and burned and hopefully this will not contaminate my oven over time. There was no residue left on the floor of the oven after burnout.
The big question is dimensional accuracy. The crowns seemed to fit the dies similarly to others I've had printed on expensive 3D printers. They need to be waxed at the margins for perfect fit, but that is acceptable for now. Hopefully the accuracy will improve as the Form software/hardware improves.