Porcelain fused to metal crowns especially will eventually have a dark line at the gumline. It can even be a black line. Procera crowns can also develop a dark line, but it isn’t as noticeable, because there is no metal in a Procera crown. Empress crowns won’t, because they are bonded, and because the material is translucent. Empress can be done so that it blends nicely into the tooth with an invisible margin.
See the pictures on the right to have this illustrated. The top picture shows two porcelain fused to metal crowns on a patient’s lateral incisors. There is a prominent dark line, even a black line, at the gumline. It is very noticeable and is in stark contrast to the white opaquer that shows just below that line, at the base of these crowns.
On the lower picture, those crowns have been replaced with all-porcelain crowns, as part of a complete smile makeover that this woman had. There is no more dark line at the gumline.
With porcelain fused to metal, the line is black, very noticeable, and ugly. With Procera, depending on how it is done, it may be more like a dark line, maybe a gray line, and it will be more subtle—it won’t be so noticeable.
For a porcelain crown on a front tooth, an all-porcelain crown such as feldspathic porcelain or Empress, or the newer all-ceramic crowns such as zirconium crowns are recommended.
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