Quote:
Originally Posted by Dean Mersky, DDS
My experience with cast PFMs is that about 75% end up with recession, many with discoloration of the root, gingiva, tooth, or any combination. The oxides necessary to bond porcelain is a major culprit, along with corrosion and the toxic nature of "some" of the components. The latter point was published in 1997 in Germany.
I have electron micro photos of the oxide layer on hi noble and NP. The Au metal has a layer of 1 micron, while the NP has 100 microns.
You might not have had complaints about tissue and NP, and clearly not everyone reacts or reacts the same. But I can promise you that there are reactions, even with other metals. I saw it for about 20 years with a variety. That is why periodontists tell GPs to stey supra ging with cast PFMs.
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That's why Captek is the only true PFM crown.....lol
Seriously though, I'm wondering if anyone has ever taken an electron microscope and looked at the oxide layer between the opaque and metal (curious to know if it's a measurable amount). If it was, it would make me wonder about fractures on traditional cast PFM's.