A grey tooth is a change in color that signals a problem originating deep within the tooth structure. Unlike external surface stains, this intrinsic discoloration is a sign of internal trauma or damage to the pulp, the living tissue inside the tooth. While a grey tooth is concerning, modern dental science offers effective ways to restore its white appearance. Natural reversal of a permanent grey tooth is rare, but professional treatments can successfully address the discoloration.
What Causes a Tooth to Lose Color?
The primary cause of a tooth turning grey is the death, or necrosis, of the dental pulp due to trauma or deep decay. The pulp contains nerves and blood vessels; injury can rupture these vessels, causing internal bleeding trapped within the tooth structure, similar to a bruise.
The grey appearance is caused by the breakdown of blood products, specifically hemoglobin. Hemoglobin degrades, releasing iron, which combines with hydrogen sulfide to form iron sulfides, a dark compound. These staining molecules are forced into the microscopic dentin tubules, leading to a permanent color change.
Is Natural Whitening Possible?
For a permanent tooth that has turned grey due to pulp necrosis, natural reversal is generally not possible. Once the pulp has died, the tooth is considered non-vital, lacking the biological mechanisms to flush out trapped staining compounds. The grey color persists because the tooth is no longer capable of self-repair.
In rare instances, following a mild traumatic injury, a tooth may experience transient discoloration that can reverse naturally. This temporary color change occurs if the pulp tissue is injured but manages to recover and maintain its vitality. If the pulp fully heals, the body can sometimes reabsorb the blood breakdown products, allowing the tooth to lighten and return to its original shade. A dentist can perform a vitality test to assess the health of the pulp and the likelihood of natural recovery.
Dental Procedures for Restoration
Restoring a grey tooth’s color requires professional intervention focused on either lightening the internal stain or masking the discoloration entirely. Before restoration, a dentist performs a vitality test and may recommend a root canal procedure to remove dead or infected pulp tissue. This ensures the tooth is healthy internally before addressing the appearance.
Internal Bleaching
Internal bleaching is a specialized procedure designed to lighten a non-vital tooth from the inside out. Unlike traditional external whitening, this method addresses intrinsic stains trapped in the dentin. The dentist creates a small opening in the back of the tooth, places a professional-grade bleaching agent directly into the pulp chamber, and seals it temporarily.
This method, sometimes called the “walking bleach” technique, allows the oxidizing agent to remain inside the tooth for several days to break down the dark staining molecules. The patient returns for follow-up visits until the desired shade is achieved, and the opening is then permanently sealed. Internal bleaching is effective for discoloration caused by trauma or previous root canal treatment materials.
Veneers and Crowns
When internal bleaching is not effective or if the tooth is structurally weakened, external restorative options like veneers and crowns mask the grey color. Veneers are thin, custom-made shells of porcelain or composite resin bonded to the front surface of the tooth. They conceal severe intrinsic discoloration, providing a natural-looking white surface.
A dental crown, or cap, covers the entire tooth structure, not just the front surface. Crowns are the preferred option when the tooth is discolored and has significant structural compromise or large fillings that make it brittle. Both veneers and crowns require the removal of some enamel to ensure a proper fit, but they offer a durable, long-term solution for restoring the tooth’s white appearance and strength.