death by zirconia and 3shape...at the end.. Let me try to help you all to understand something. by providing and promoting full contour zirconia crowns we are doing a disservice to patients. Think about it like this: take a rock grinder, place a few opal stones in it, tumble, they simply get shined more; now though in a diamond, in a few hundred cycles you will have nothing but dust, and a slightly smoothed diamond...The same thing will happen in the mouth with full contour zirconia: contacts will open after tooth gnathalogical processes (tooth movement from attrition) opposing teeth will wear often changing function and slowly one tooth can destroy the entire mouth. NEXT... we are all trying to layer to zirconium, zirconium has NO chemical bond only mechanical retention, it can't... ever.. zirconium has no oxidation to bond to. slight wetting of surface is not an adequate bonding layer..E'max is doing the best with there bonder layer for layering zirconium, as it is designed to fire at a higher temp, but, as I have personally seen, even some of the best labs in the country are foregoing it "cuz its a pain to use". The silly idea to just turn up your oven temp for a "bonder" layer is stupidity.. learn your materials! More lucite crystals form when you over cook your porcelain, lucite crystals are weak and the more you have the more likely you will have breakage in the future.It takes a while sometimes but wear is a long process, just because it leaves the lab does not mean its ok later.... thats why we try to cool our pressings guys..to PREVENT over growth of lucite crystals that form. Doctors are seeing chipping more and more..get off the zirconium band wagon and come back to reality. zircon grows with advertising but can die with knowledge..
and thank you for your thread. I am looking forward to purchasing the new model of the 3Shape in the spring of 12' for my one person lab
