Why Is My Tooth Turning Black At The Gum?

A black spot at your gum line is a sign that something is wrong with your tooth, and it needs attention. The most common cause is tooth decay, but it can also be trauma, a dead nerve, or a type of stain. Ignoring it won’t make it go away, and the underlying issue will likely get worse. A dentist needs to look at it to tell you exactly what is happening.

What Does a Black Tooth at the Gum Line Mean?

The color change you are seeing is not the tooth surface itself turning black. It usually means one of two things. Either the hard outer layer of the tooth, called enamel, has been destroyed by decay, or the inner part of the tooth is dying.

When decay reaches the dentin underneath the enamel, it can stain dark. Dentin is naturally a darker yellow or brown color. When it is exposed and breaks down, it can look black, especially at the gum line where plaque builds up easily.

A dead nerve inside the tooth can also cause it to darken. This happens when the blood supply to the tooth is cut off, often from trauma or deep decay. The breakdown of red blood cells inside the tooth releases iron, which turns the tooth a gray, brown, or black color from the inside out.

Why Is My Tooth Turning Black At The Gum?

Several specific problems can cause this exact appearance. Each has a different cause and needs a different treatment.

Cavities at the gum line. This is the most common reason. Plaque and bacteria collect right where the tooth meets the gum. They produce acid that eats away the enamel. Because the enamel is thinner there, decay can spread quickly. The cavity may look like a small black dot or a dark line along the gum.

Amalgam tattoo. If you have a silver filling nearby, tiny metal particles can sometimes get trapped in your gum tissue. This creates a flat, dark gray or black spot on the gum itself. It is harmless and looks like a tattoo. It does not affect the tooth.

Trauma. A fall, a sports injury, or even biting something hard can damage the blood vessels inside the tooth. If the blood supply breaks, the tooth can die and darken. This can happen weeks or even months after the injury. The entire tooth may look gray or black, not just the gum line.

Certain medications. Some antibiotics, particularly tetracycline, can stain teeth if given to children whose teeth are still forming. This is less common now but can cause permanent dark bands on the teeth.

Tartar buildup. Hardened plaque, called tartar or calculus, can form below the gum line. It is often yellow or brown, but in some people it picks up stains from food, drinks, or tobacco and turns very dark. This is a stain on the tooth, not decay. A dentist can scrape it off.

Internal bleeding. A tooth that has had a root canal or a large filling can sometimes bleed internally. This is rare, but it can cause the tooth to darken from the inside.

Is a Black Tooth an Emergency?

A black tooth is not always a dental emergency, but it is a serious problem that should not wait. If you have no pain, you should still see a dentist within a week or two. The decay or nerve damage will not heal on its own.

See a dentist immediately if the black tooth comes with any of these signs:

• Severe pain that does not go away
• Swelling in your face or jaw
• A bad taste in your mouth
• Fever
• The tooth feels loose

These symptoms can point to an abscess, which is a pocket of pus caused by a bacterial infection. An abscess is a serious condition that can spread to other parts of your face and body. It needs urgent dental care.

What Will the Dentist Do?

The treatment depends entirely on what is causing the discoloration. No home remedy will fix a black tooth. The dentist will examine the tooth, possibly take an X-ray, and then recommend one of the following options.

For a cavity: The dentist will remove the decayed part of the tooth and place a filling. If the decay is very large, you may need a crown, which is a cap that covers the whole tooth. If the decay has reached the nerve, you will need a root canal to remove the infected tissue.

For a dead nerve: A root canal is the standard treatment. The dentist removes the dead nerve and blood vessels from inside the tooth, cleans the space, and seals it. After a root canal, the tooth often needs a crown to protect it. The tooth may also need internal bleaching to restore its color.

For tartar: A professional cleaning can remove the hardened deposits above and below the gum line. This is called scaling and root planing. The tooth will look cleaner, but the dark stain may have permanently etched the enamel.

For an amalgam tattoo: No treatment is needed for the tattoo itself. If you do not like how it looks, a dentist can sometimes remove it with a small surgical procedure, but this is purely cosmetic.

For a tooth that cannot be saved: If the tooth is too badly decayed or the root is fractured, the dentist may recommend extraction. Removing the tooth is often the last option, but it is sometimes the only way to stop the infection and pain.

Can a Black Tooth Be Whitened?

Whitening toothpaste and over-the-counter strips will not help a black tooth. These products work on the surface of the enamel. They cannot reach decay inside the tooth or change the color of a dead nerve.

For a tooth that has darkened after a root canal, a dentist can sometimes use internal bleaching. This involves placing a bleaching agent inside the tooth for a short time. The results can be good, but the tooth may darken again later.

For a tooth that is stained by tartar, removing the tartar will help, but the enamel underneath may have lost its natural whiteness. Professional whitening after a cleaning can help restore a more even color.

How to Prevent a Tooth From Turning Black

Prevention is far easier than treatment. Most of the causes of a black tooth are preventable with consistent habits.

Brush your teeth twice a day with a fluoride toothpaste. Pay special attention to the gum line, where plaque collects. Angle the bristles toward the gum at a 45-degree angle and use gentle circular motions.

Floss once a day. Brushing cannot reach the tight spaces between teeth. Flossing removes plaque and food particles that cause cavities at the gum line.

See your dentist for regular checkups and cleanings. A dentist can find small cavities before they become black holes. Professional cleanings remove tartar that you cannot brush away at home.

If you play contact sports, wear a mouthguard. A simple blow to the mouth can kill a tooth’s nerve, and you may not notice the darkening for weeks. A custom-fitted mouthguard from your dentist offers the best protection.

What Happens If You Leave a Black Tooth Alone?

Leaving a black tooth untreated is a risky decision. The problem will not stay the same. It will get worse over time.

If the cause is decay, the cavity will grow larger. It will eventually reach the nerve, causing pain and infection. An untreated infection can spread to the jawbone or other parts of the face. In serious cases, it can enter the bloodstream, a condition called sepsis that is life-threatening.

If the cause is a dead nerve, the tooth will become brittle over time. It may crack or break. The infection from a dead nerve can also form an abscess, even if you do not feel pain.

The longer you wait, the more complex and expensive the treatment becomes. What might have been a simple filling can turn into a root canal and a crown. A tooth that could have been saved may end up needing extraction.