Black Line at Base of Crown

Darkness at Gumline

It almost looks like you might have black gums above your crown. But the hygienist says that you have healthy gums and certainly no gum disease. So if your oral health is good, then what could it be? Are your crowns older than 9 years? If so, you may  have noticed a thin black line at base of the crown?

Is that darkness at the gumline decay or an amalgam tattoo? Plaque? Tartar? Before you worry that you have a medical condition such as oral cancer, continue reading to learn what this dark line is.

If you are unhappy with a dental crown that doesn’t match your natural smile, we can help. As one of Chicago’s top cosmetic dentists, Dr. Fondriest helps patients from all over the greater Chicago area, and across the country, create a smile they love. We offer unique “artistic smile design” which crafts smiles not just for function, but aesthetics. If you’d like more information, or would like to schedule a cosmetic consultation, call us at 847-234-0517.

black line at gumline

A black line will form at the base of a crown when a crown leaks at the margin. This black line can also occur in a low quality crown when the underlying metal isn’t concealed.

The Thin Black Line at the base of a crown | Darkness at Gumline

That darkness at the gumline is not unhealthy tissue. Surprisingly, the thin black line is actually a part of your dental crown. Porcelain-fused-to-metal (PFM) crowns have long been a standard in cosmetic dentistry. Before all-ceramic and zirconia crowns were available, Porcelain-on-metal crowns were the only alternative to a very obvious metal crown.

On front teeth, metal crowns would stand out. Dentists eventually found a solution for helping a crown to blend in with the rest of the smile. This is how the porcelain-fused-to-metal crown was born. Unfortunately over time, the gum tissues will recede from a result of aging, periodontal disease, or aggressive brushing. Eventually a dark or black line is revealed at the base of the crowned tooth, right on the gum line. When the dark line develops, the previously “seamless” look of your PFM crown is gone.

Not all crowns are made equal and many have darkness at the gumline

The truth is, the quality of your PFM crown depends on how it’s made. Dentists pay a ceramist from $35 to $1700 to make a PFM crown. For just $60 more, the crown can have a porcelain butt joint margin. If your gums recede, no metal (that black line) will be revealed. Instead, the tooth will look completely white.

This darkness at the gumline is more likely to occur with a low quality crown. With cheaper versions, the underlying metal isn’t properly concealed with porcelain. If a world class technician creates your crown, it will be difficult to tell it isn’t real.

Darkness at gumline

Photo of PFM crowns with metal margins exposed on lower back teeth. The black line at base of these crowns are not due to poor oral care or lack of brushing and flossing. Brushing your teeth will not get rid of this darkness at the gumline.

Sensitivity to some types of metal used in your restorative dentistry

Another consideration is the metal material used. An inexpensive alloy will not cast as well (part of the fabrication process). A poorly fitted crown won’t fit as well as it would if a better precious metal were used. Also, biocompatibility may be a problem. If the body reacts negatively to the non-precious metal alloy, it could cause receding gums.

With inexpensive crowns, the ceramic baked over the metal may be more opaque and less natural looking. Your best option is a 14+ karat gold crown under veneering ceramic, with a butt joint margin. With a full gold underlay, The crown will fit better and match better. If you get the butt joint margin, it is less likely to have a darkness at the gumline.

On the other hand, all-porcelain crowns are often the most natural looking option for front teeth. The porcelain material can resemble enamel much more closely than PFM crowns. Sometimes, a PFM crown can appear flat or stark white, because of the dense, dark-colored metal underneath the porcelain.

It is normal to be concerned about the aesthetics of your smile. Do you want to get rid of the darkness at the gumline? If you want to improve the overall look of your old crown, a porcelain only cap could be the best option.

Good or Bad: Porcelain-Fused-to-Metal Crowns

Today, some patients have heard that PFM crowns are not good for their teeth. Many patients will ask whether they should have them removed and replaced with a non-metal porcelain crown. The short answer, is not necessarily: PFM crowns are not bad for your health.

If a porcelain-fused-to-metal crown is strong, comfortable and properly functioning, it does not need to be removed. While some cheaper or significantly older PFM crowns will display a darkness at the gumline, others will not. If it has what is called a porcelain “margin”, it will not reveal metal even after gum recession occurs. This is because special precautions were made when making the better version crown, to ensure that the black line never develops.

For some patients an exposed metal margin in the back of the mouth may not be bothersome. The thin black line may be indistinguishable when speaking or eating. However, if this is present on a front tooth, most will look for a replacement. A new higher quality PFM or a new porcelain crown. By replacing old or poorly made PFM crowns, you can hide any evidence that your crown isn’t natural enamel.

Learn more about fixing the black line at the base of your crown

Have you have developed a thin black line at the base of a crown? Especially one that is near the front of your smile. Would you like to replace your old dentistry with life-like crowns? Dr. James Fondriest can help! Call us to schedule a consultation with Dr. Fondriest and discover your options for attaining a more natural-looking dental crown. If you are looking for invisible restorations, schedule a consultation by calling us at 847-234-0517.

Dr Fondriest is a nationally recognized and highly sought after cosmetic dentist. He serves clients from throughout the United States