Why Is One Tooth Darker Than the Rest of My Teeth?

When I look in the mirror, one tooth seems noticeably darker than the others. It’s got a grayish brown appearance even though the other teeth look perfectly fine. I’ve tried whitening toothpaste and even professional teeth whitening without seeing any real difference.

Is there any way to get this tooth white?

Judy

Dear Judy,

When just one tooth becomes discolored, the problem may be inside the tooth rather than on its surface. In some cases, internal tooth bleaching can brighten the tooth from the inside while preserving your natural tooth structure. If you’re not a candidate for that, you have two other options I’ll go over in a moment.

Why Would Just One Tooth Turn Dark?

A single tooth can become discolored for several reasons. One common cause is trauma. If a tooth has been struck or injured, bleeding can occur inside the tooth. As the trapped blood cells break down, they release iron which stains the tooth. If the trauma itself is severe enough, the nerves and tissue in the tooth dies. As the tissue decomposes, that can also turn the tooth darker.

Traditional teeth whitening treatments work primarily from the outside of the tooth inside. That can make them very effective for many common stains and discoloration.

However, if the discoloration originates inside a root canal treated tooth, whitening the outside will not be enough. You could end up with the surrounding teeth becoming brighter while the darker tooth remains noticeably different.

That’s where internal tooth bleaching may help. This is a whitening technique used for some discolored teeth that have already had or need a root canal treatment.

Instead of applying the whitening material only to the outside surface, an endodontist accesses the inside of the tooth and places a bleaching material within it. The opening is then temporarily sealed.

Over time, the whitening material works from within the tooth to lighten the discoloration. Depending on the severity of the staining and how the tooth responds, the process may need to be repeated before the desired shade is achieved.

This technique is sometimes called walking bleach because the patient walks away with the bleaching material temporarily sealed inside the tooth.

Other Options: A Dental Crown or Porcelain Veneer

Crowns and veneers can change the appearance of a discolored tooth, and there are situations where they may be the appropriate treatment. Preparing a tooth for a veneer or crown requires removing some natural tooth structure. When an otherwise healthy root canal-treated tooth is a good candidate for internal bleaching, whitening the tooth internally may improve its appearance while preserving more of the existing tooth.

Your dentist or endodontist can evaluate the condition of the tooth and determine whether internal bleaching or a restorative treatment makes more sense in your particular situation.

Can Any Dark Tooth Be Bleached From the Inside?

No. Internal bleaching is intended for specific situations, particularly discoloration involving a tooth that has undergone a root canal treatment.

Before bleaching a tooth internally, your endodontist needs to examine the tooth. If there is an untreated infection, a problem with the existing root canal, a crack, or another dental concern, that issue will need to be addressed first. That’s one reason an evaluation is important rather than simply assuming that a dark tooth needs whitening.

This blog is brought to you by a compassionate endodontist in San Antonio, Dr. Scott Janse.