A dark tooth can make you feel uncomfortable when you smile, especially if the rest of your teeth are white. Fortunately, there are several ways to improve the color of a tooth. If the tooth has already had a root canal treatment, one of the best options may be internal bleaching.
Unlike regular teeth whitening, internal bleaching works from the inside of the tooth instead of the outside. Although a crown can restore the strength of a tooth, it does not always solve the problem of discoloration. In many cases, internal bleaching is recommended before making the final crown.
By the end of this post, you will understand what internal bleaching is, would a tooth becomes dark after a root canal, who is a good candidate, how the procedure works, what happens after bleaching, how long the results last, and what to expect in terms of cost and insurance coverage.
What Is Internal Bleaching?¹
Internal bleaching is a procedure that whitens a tooth from the inside. It is only performed on a tooth that has already had a root canal treatment. During the procedure, your dentist places a whitening material inside the tooth. The material stays inside the tooth for several days before it is replaced or removed. This process continues until the desired shade is reached.
Once the tooth reaches the desired color, the whitening material is removed, and the opening is permanently sealed with a tooth-colored filling.
Would a Tooth Become Dark After a Root Canal?²
Many people believe that root canal treatment causes a tooth to become dark. The answer is not exactly.
A tooth can become darker because of bleeding inside the tooth after an injury, the breakdown of tissue inside the tooth before the root canal treatment, or materials that were previously used during treatment. Over time, these substances stain the tooth from the inside.
Fortunately, internal bleaching can remove many of these stains and improve the appearance of the tooth.
Who Is a Good Candidate?
Internal bleaching may work for you if you have:
- A tooth that has already had a root canal treatment
- One tooth that is darker than the surrounding teeth
- No active infection around the tooth
- Enough healthy tooth structure to support a filling or crown if needed
Who May Not Qualify for Internal Bleaching?
Internal bleaching may not work for you if you have:
- A tooth that has not had a root canal treatment
- An active infection around the tooth
- A cracked tooth that cannot be repaired
- A tooth that needs another root canal treatment
What Is the Internal Bleaching Procedure Like?
What Happens After Internal Bleaching?⁴
Internal bleaching can greatly improve the color of a dark tooth. However, some teeth also need a crown after bleaching. This is common when the tooth has lost a large amount of structure because of decay, trauma, or the root canal treatment itself. A crown helps protect the tooth from breaking.
In some cases, if a crown is needed, bleaching is usually completed first. This is important because if a crown is placed directly on a dark tooth, the dark color may show through the crown or affect the final appearance.
Before & After: Internal Bleaching on one of our patients at Gleam Dentistry.
Does Internal Bleaching Hurt?³
Most patients do not experience pain during internal bleaching. Since the tooth has already had a root canal treatment, the nerve has been removed. Some patients may notice mild pressure or tenderness around the tooth, which goes away within a short time.
Re-bleaching?
The results of internal bleaching can last for many years with good oral hygiene and regular dental check-ups. However, every patient is different. In some cases, the tooth may slowly become darker again over time.
Fortunately, rebleaching is often possible. If the tooth becomes dark again, your dentist may recommend repeating the internal bleaching procedure to improve the color.
What Is the Cost of Internal Bleaching and Will Insurance Help?
The cost of internal bleaching depends on the condition of the tooth and the number of appointments needed to reach the desired shade. If additional treatment, such as a filling or a crown, is needed after bleaching, the total cost may be higher.
Since internal bleaching is usually performed to improve the appearance of a dark tooth, many dental insurance plans consider it a cosmetic procedure and do not cover it.
However, our office in Modesto can evaluate your tooth, explain your treatment options, review your insurance benefits, and discuss financing options if needed.
References:
- Rybalko A. A conservative solution for discolored endodontically treated teeth. Dimensions of Dental Hygiene. 2025. Available from: https://dimensionsofdentalhygiene.com/article/a-conservative-solution-for-discolored-endodontically-treated-teeth/
- Rockland Dental Specialists. Internal bleaching after root canal [Internet]. New City (NY): Rockland Dental Specialists; [cited 2026 Jul 1]. Available from: https://www.rocklanddentalspecialists.com/internal-bleaching-after-root-canal/
- Essential Endodontics. Internal tooth bleaching: Managing sensitivity tips [Internet]. [cited 2026 Jul 1]. Available from: https://essentialendotx.com/internal-tooth-bleaching-managing-sensitivity-tips/
- Ceroni F. Use of internal bleaching in prosthetic cases [Internet]. Style Italiano Endodontics; 2024 [cited 2026 Jul 1]. Available from: https://endodontics.styleitaliano.org/use-of-internal-bleaching-in-prosthetic-cases/
Credits:
Authored by: Omar Halimi
Edited by: Stephanie Diego DDS MPH
Published on July 1st, 2026