A non-vital tooth, commonly referred to as a “dead tooth,” is one where the pulp tissue inside the tooth’s innermost chamber has died due to trauma or infection. This pulp contains nerves and blood vessels that are no longer supplying the tooth with nutrients. When the blood supply is lost, the hemoglobin within the red blood cells breaks down, releasing pigments that seep into the microscopic channels of the dentin. This causes the tooth to slowly turn a distinct yellow, brown, or grayish-black color, making it noticeable against surrounding healthy teeth. This internal discoloration cannot be resolved with standard whitening products, necessitating specialized dental treatment.
Understanding the Limits of Standard Whitening
The discoloration of a non-vital tooth is a deep-seated problem that external whitening agents cannot address effectively. Standard over-the-counter strips and gels treat extrinsic stains, which are surface discolorations caused by external factors like coffee, red wine, or tobacco use. These products work by applying a bleaching agent directly to the enamel to break down chromogens on the tooth’s outer layer.
A discolored dead tooth, however, exhibits intrinsic staining, meaning the pigments are embedded deep within the dentin beneath the enamel. The source of this color change is the breakdown of internal pulp tissue and blood products within the dentinal tubules. Since external whitening applications cannot penetrate the dentin in sufficient concentration to neutralize these internal pigments, they are ineffective on non-vital teeth. Addressing this discoloration requires a professional procedure that works on the tooth from the inside out.
Internal Bleaching: The Primary Treatment Method
The most conservative and common treatment for a discolored non-vital tooth is internal bleaching, often performed using a technique known as the “walking bleach.” This method involves placing the whitening agent directly into the pulp chamber of the tooth. The procedure is only possible after the tooth has undergone root canal therapy, which removes all the non-vital pulp tissue.
The dentist accesses the pulp chamber, usually from the back of the tooth, through the existing root canal access opening. A primary step is the placement of a protective cervical barrier, typically a two-millimeter layer of glass-ionomer cement, over the root canal filling material. This barrier seals the root space at the cemento-enamel junction, preventing the bleaching agent from leaking out. Preventing this leakage protects the root structure and surrounding tissues.
Next, the active bleaching agent is placed directly into the cleared coronal pulp chamber. The agent is often a paste formed by mixing sodium perborate powder with water or a low-concentration hydrogen peroxide solution. The chamber is then sealed with a temporary filling, allowing the mixture to remain active for several days. This technique is called “walking bleach,” as the agent works while the patient goes about their daily activities.
The active oxygen radicals released by the bleaching agent penetrate the dentinal tubules, breaking down the darkly colored pigment molecules into smaller, colorless compounds. The patient returns after three to seven days for the dentist to evaluate the color change. The process may be repeated over multiple visits until the desired shade is achieved, lightening the tooth from the inside out to match adjacent teeth.
Cosmetic Alternatives to Bleaching
If internal bleaching is not an option, several external cosmetic alternatives are available to mask the discoloration. These restorative treatments are more invasive than bleaching, as they cover the tooth surface rather than altering the tooth’s intrinsic color.
Composite Bonding
The least invasive option is composite bonding, where a tooth-colored resin material is applied directly to the tooth’s front surface, sculpted, and hardened with a curing light. This method is quick, often completed in a single visit, requires minimal removal of the natural tooth structure, and is a cost-effective solution for minor discoloration.
Porcelain Veneers
A more durable alternative is the porcelain veneer, a thin, custom-made ceramic shell bonded to the front surface of the tooth. Veneers require the removal of a small amount of enamel to create space for the material, ensuring a natural fit. They are highly stain-resistant and can completely cover severe discoloration, providing a long-lasting aesthetic result.
Full Coverage Crowns
For a tooth that is discolored and structurally compromised—such as one with an extensive filling or significant fracture—a full coverage crown may be necessary. A crown completely encases the entire visible portion of the tooth down to the gum line. This option requires the most substantial removal of the natural tooth structure, but it provides maximum strength, protection, and a uniform aesthetic, restoring both appearance and function.
Post-Treatment Expectations and Care
After successful internal bleaching, the tooth requires a permanent restoration to seal the access opening and maintain the result. The final filling or bonding material should be placed only after a waiting period, typically two to three weeks, allowing residual oxygen from the bleaching agent to dissipate. This waiting period ensures optimal bonding strength between the tooth structure and the restorative material, preventing premature failure.
One potential complication associated with internal bleaching is external cervical root resorption, where the root surface near the gum line begins to dissolve. This risk is linked to the use of high-concentration agents and a lack of a proper protective cervical barrier during the procedure. Modern protocols, including the careful placement of the protective cement barrier, are designed to mitigate this risk. Patients should also be aware that some color relapse can occur over time, potentially necessitating a touch-up bleaching session years later.