What's that dark line at the gum line of my crown (or "cap")?

All Ceramic Dental Crowns / Veneers

By Dr. Chris Campbell, Lexington, SC

This is a question that we hear frequently in our office during our new patient exams.  It’s a great question, so let’s shed some light on the topic.  The majority of the crowns (or "caps") that have been fabricated worldwide are of the “porcelain bonded to metal" variety.  What that means is that there is a metal substructure that fits over the prepared tooth upon which porcelain is layered to make it look like a tooth.  Many times this metal and porcelain junction can result in a black line at the base of the crown, where it had initially been tucked slightly under the gums.  If any gum recession occurs, the patient may then see the black metal line.

 
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While the porcelain fused to metal crown is still a very durable, long lasting restoration (and can be fabricated in a method that doesn’t show the “black line”), we now have new materials available to us that allow for crowns to be made with absolutely no metal at all.  Is this a brand-new concept?  No, it is not.  We have been making metal-free crowns and veneers for many years.  Unfortunately, in past times we have had to sacrifice strength in order to gain the esthetic benefit of a metal free crown.  With the advent of materials like porcelain bonded to zirconia, and even more recently, a highly esthetic porcelain called Emax, we are able to achieve the ultimate in esthetics without sacrificing strength.  

With the advent of these new materials and by using truly artistic master ceramists to fabricate our crowns, no longer do we have to make crowns that look like crowns.  Instead, we now can fabricate crowns that look like, well... beautiful, natural, healthy teeth!