In the production process of metal-supported porcelain veneers, before porcelain powders are deposited onto the metal substructure, the metal block is fired at high temperatures to form a microscopic “oxide layer” on its surface. This oxide layer acts as a bridge, chemically bonding the metal and porcelain. If the temperature is incorrectly set during firing, if the metal is of poor quality, or if the oxide layer becomes contaminated during cleaning, this layer will become excessively thick or brittle. When the veneer is placed in the mouth and chewing forces begin to apply, this weak bond between the porcelain and the metal breaks, and the porcelain veneer separates from the metal in pieces (delamination). This is a veneer failure entirely due to laboratory and material quality errors.
