That Ugly Black Line

We’ve all seen it – that ugly black line along the gum line that is often associated with crowns. It’s a common problem, particularly for patients who have had their crown for more than ten years. Yet, few know why this happens or how easily it can be fixed. It’s a conversation that I often have with patients and one that may be beneficial to those who have noticed this “ugly black line.” 

This “before” photo shows the UBL.  The photo below is after existing crowns are replaced using all porcelain restorations,  No more UBL!




Understanding the Line

One of the first questions I get from patients who have noticed this dark line is this: How did this happen? The answer to this question is simple. Prior to mainstream use of all-porcelain crowns, most crowns were prepared as porcelain fused to metal. This was the standard crown for dentists roughly ten years ago. However, if this crown was not prepared properly, or the gum line began to recede, the metal in the crown would show.

The black line is simply the junction between where the crown and the tooth meet. And if this juncture occurs above the gum line, the metal will be visible to the eye. Thus, creating that unattractive black line.

Over the years, this issue has really given crowns a bad name. In fact, it’s the main reason that many of my patients are so hesitant to get a crown placed. But this outcome is no longer the norm, and for patients whose crowns do have this appearance – it can be fixed.

The New Normal

Fortunately today, the majority of crowns are all porcelain – meaning that the metal causing this problem is no longer a part of the crown preparation. These all-porcelain preparations allow for much more natural looking teeth because the material used transmits and reflects light very similar to your natural teeth.

These crowns are typically more expensive than the porcelain-fused to metal crowns, however, the result is much better, and in my professional opinion, worth the cost.

For those patients with existing metal crowns that have the appearance of a black line, the good news is that these can easily be replaced with their all-porcelain counterparts. This is not a difficult process, and is well worth the cost if you are unhappy with your current smile.

To replace the current crown, your dentist must simply make a slit through the existing porcelain and underlying metal – just to the point of tooth contact –then pop the crown off using a special tool. This will break the cement seal and remove the crown without damaging the underlying tooth.

From there, a new impression will be taken to create the porcelain crown, which can be placed in the same day. From start to finish, this will take only about an hour and a half of your day. And once it’s done, the whole shape of your smile will be improved. No longer will you have to worry about hiding that imperfection along your gum line or worrying if people notice the line. For those patients who have had this done, it has been with overwhelming satisfaction in the final result.

If your crown is giving the appearance of that “ugly black line,” call us at (813) 689-4226 to schedule a consultation today.




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