Can a darkened root canal tooth be whitened?

Maybe you've been wondering why your tooth that underwent a root canal has now darkened, and whether anything can be done about it. The good news is a dental provider may be able to whiten it from the inside out, depending on your tooth. They'll check it first, then walk you through your options. 

What you will learn in this article: 

• A root canal tooth can darken from the inside, and a dental provider may be able to bleach it from within. This is called internal bleaching. 

• Bleaching may be preferable to a crown when the tooth is relatively intact. 

• External cervical resorption is a rare risk, and your dental provider can explain the signs to watch for. 

• A heavily broken-down tooth may need a crown instead. 

If your tooth has changed color, schedule an appointment with an Aspen Dental provider. Your care team can check the tooth and explain what options may fit you. 

Why does a root canal tooth darken? 

This type of color change starts inside the tooth. The American Dental Association (ADA) calls it an intrinsic stain. Both the ADA and a separate case report note that trauma, a dead tooth nerve, materials from root canal treatment and past fillings can all contribute to this type of discoloration.¹^,²

Can a dental provider whiten a root canal tooth? 

Yes. Internal bleaching is used for a discolored tooth whose nerve is no longer alive. This method places whitening material inside the tooth, such as hydrogen peroxide, carbamide peroxide or sodium perborate.¹  

For a tooth that is still mostly intact, a case report describes bleaching as a less invasive option than covering the tooth with a crown. It also describes an inside-outside method that whitens the inner and outer parts during the same treatment.² 

How does internal bleaching work? 

Your dental provider will explain each step before treatment. The exact plan can vary from tooth to tooth. 

In two case reports, dental providers removed root-filling material to about 2 millimeters below the gumline, then placed a protective barrier over the remaining material before bleaching the tooth.²^,³ 

Ask your dental provider how they would plan your treatment and how many visits it may take. 

Are there risks? 

Internal bleaching has rarely been linked to external cervical resorption. This means the outside of the tooth root begins to break down near the gumline. Overall, this complication is uncommon.¹ 

If you have questions, talk with your dental provider. They can tell you if bleaching suits your tooth and explain any signs to watch for. 

What if the tooth is not intact? 

If a tooth is still mostly whole, internal bleaching may be an option. If it is heavily worn or broken down, your dental provider may discuss other options, including a crown. 

Your dental provider can look at how much healthy tooth is left. Then they can help you weigh the choices. 

If your root canal tooth has darkened, contact your local dental provider to have it checked. Your care team can explain whether bleaching or another option may fit. 

Can a darkened root canal tooth be whitened? FAQs 

Still have questions about whitening a root canal tooth? These answers add details not covered above. 

Can I whiten a root canal tooth at home? 

No. Internal bleaching is a dental procedure because the whitening material must be placed inside the tooth. Ask your dental provider whether this treatment is right for you. 

What goes inside the tooth to bleach it? 

Internal bleaching may use hydrogen peroxide, carbamide peroxide or sodium perborate. The product and strength depend on the tooth and the method being used. Ask your dental provider what they plan to use. 

What can lower the risk of root damage? 

A case report on this topic says a thin cement layer between the root filling and the bleach can help protect the root. It recommends making this barrier 1 to 2 millimeters thick. 

The same case also describes leaving calcium hydroxide in the tooth for one week before placing the final filling. This helps clear leftover oxygen and may lower the risk of root damage. It further warns that high-strength bleach used with heat has been linked to cervical root resorption in reported cases.³ 

Ask your dental provider which safety steps they plan to use. 

Sources 

¹ American Dental Association, Library and Archives: “Whitening.” https://www.ada.org/resources/ada-library/oral-health-topics/whitening 

² National Institutes of Health, Journal of Natural Science, Biology and Medicine: “Bleaching of a non-vital anterior tooth to remove the intrinsic discoloration.” https://pmc.ncbi.nlm.nih.gov/articles/PMC4121941/ 

³ National Institutes of Health, Current Health Sciences Journal: “Non-vital Endo Treated Tooth Bleaching with Sodium Perborate.” https://pmc.ncbi.nlm.nih.gov/articles/PMC6993762/