It should be noted that the crown prostheses porcelain applied in the routine have for base a grey metal alloy. These create a grey reflection in the area of the gingival tissue, especially when they are applied on the teeth of the region previous.
The dissolution of the metal alloy in the bottom of the porcelain linings made in that, over time, the gums appear to be gray.
The light transmission of porcelain is also reduced by the metal which that these coatings appear in a dull matte color.
In addition, the e-max creates an aesthetic appearance and more natural due to the transmission of the light that is closer to the enamel of the teeth.