A “dead tooth,” medically termed a non-vital tooth, has suffered irreversible damage to the dental pulp, the soft tissue inside the tooth. This damage, often from trauma or extensive decay leading to root canal treatment, causes the tooth to lose its natural vitality. Unlike external whitening applied to the surface, a non-vital tooth requires a specialized, internal approach to address deep-seated discoloration. Yes, a dead tooth can be whitened, but the process is fundamentally different and must be performed by a dental professional.
Why Pulpless Teeth Darken
The discoloration seen in a non-vital tooth is intrinsic staining, originating within the tooth structure, specifically the dentin. When the pulp dies, blood vessels within the pulp chamber rupture and break down. This process releases blood components, including hemoglobin and iron, which penetrate and become trapped within the microscopic tubules of the surrounding dentin.
Over time, these breakdown products undergo chemical changes, causing the tooth to display a noticeable gray, dark yellow, or brownish color that resists traditional external bleaching methods. This internal staining causes the tooth to appear dark relative to its neighbors, making a targeted solution necessary.
The Internal Bleaching Technique
The specialized procedure used to lighten a non-vital tooth is internal bleaching, often performed using the “walking bleach technique.” The process begins by re-accessing the pulp chamber, typically through the existing root canal opening. The dentist cleans out any remnants of old filling materials or discolored dentin contributing to the stain.
A protective barrier, often glass ionomer or similar cement, is then placed over the root canal filling material in the cervical (neck) region of the tooth. This cervical seal prevents the bleaching agent from leaking onto the root surface. The bleaching agent is prepared, usually a paste made from sodium perborate powder mixed with water or a low concentration of hydrogen peroxide.
This paste is placed directly into the cleaned pulp chamber and sealed inside the tooth with a temporary filling. The term “walking bleach” refers to the patient leaving the office with the agent sealed inside, where it works continuously over several days. The patient returns after three to five days for the dentist to evaluate the shade change and repeat the process if the desired color has not yet been achieved.
Managing Expectations and Risks
Patients should understand that while internal bleaching is effective, obtaining a perfect, permanent shade match to adjacent teeth can be challenging. Color correction is not always permanent, and discoloration relapse is possible over time, sometimes requiring re-treatment.
The primary, though rare, complication is external cervical root resorption, where the body dissolves the root structure near the gumline. This serious issue is mitigated by using a proper protective barrier over the root canal filling. Modern techniques and the preferred use of sodium perborate mixed with water over high-concentration hydrogen peroxide have significantly reduced this risk. The treatment is considered a conservative and cost-effective method compared to alternatives like crowns or veneers.