Teeth grinding, known as bruxism, generates extreme forces that lead to structural damage. This repetitive stress causes tiny breaks in the enamel that deepen over time. A cracked tooth resulting from bruxism is a serious issue, requiring both repair of the damage and addressing the underlying habit.
Understanding the Damage Caused by Grinding
Bruxism creates a spectrum of damage, ranging from superficial imperfections to deep structural failures. The least severe are Craze Lines, microfractures contained entirely within the outer enamel layer. These hairline cracks are often painless and typically do not require restorative treatment.
More significant damage is categorized as a Fractured Cusp or a Cracked Tooth. A fractured cusp involves a piece of the chewing surface breaking away, often occurring around an existing filling, but usually does not extend into the pulp.
A true cracked tooth (Cracked Tooth Syndrome) is an incomplete fracture that starts on the chewing surface and extends vertically toward the root, potentially reaching the inner pulp layer.
Dentists use specific tools to diagnose the depth and path of these fractures, which determines the appropriate repair. Transillumination involves passing a high-intensity light through the tooth, making the crack line appear dark against the enamel. Dental dyes can also be applied to stain the fracture, making it visible. Diagnosis also involves checking for sensitivity to biting pressure to isolate the pain.
Non-Invasive and Minor Repair Options
For minor cracks confined to the outer layers of the tooth, less intensive restorative treatments can stabilize the structure. Dental bonding is a common solution for hairline cracks or small chips. This procedure involves applying a tooth-colored composite resin directly to the tooth surface, molding it to fill the fracture, and then hardening it with an ultraviolet light.
Bonding is effective because the resin material seals the crack, preventing bacteria from infiltrating the tooth and causing decay or infection. This restoration is performed in a single office visit and is cost-effective. Similarly, dental sealants, thin layers of resin, can be applied to the chewing surfaces to protect shallow cracks.
Advanced Restorative Treatments for Severe Cracks
When a crack extends deeper into the tooth structure, more robust restorations are necessary to hold the tooth together and prevent splitting. For damage too large for a simple filling but not requiring full coverage, a custom-fabricated inlay or onlay may be used.
An inlay fits within the cusps of the tooth, while an onlay is a larger restoration that extends over one or more cusps (a partial crown). These restorations preserve more natural tooth structure compared to a full crown.
A full dental crown is required when a significant portion of the tooth is compromised, such as with a fractured cusp or a crack that threatens to split the tooth. The crown, a cap made of porcelain, ceramic, or metal, covers the entire visible portion of the tooth, holding the weakened structure together.
Crowns are often necessary for teeth that have undergone a root canal procedure, as the tooth becomes more brittle and requires full coverage.
If the crack penetrates the dental pulp, bacteria can enter, leading to infection and severe pain. Root canal therapy is performed to remove the infected pulp, clean the inner chambers, and seal the root canal system.
After root canal treatment, the tooth must be protected with a full crown to prevent fracture. Extraction is a last resort, usually only necessary if the crack extends deep below the gum line or involves an unsalvageable vertical root fracture.
Addressing the Root Cause: Stopping the Grinding
Repairing the cracked tooth is only a temporary fix if the underlying cause of bruxism is not managed. The most common preventative measure is a custom-fitted occlusal splint or night guard. This appliance creates a protective barrier between the teeth, absorbing the intense forces of grinding and preventing further wear. While it protects the teeth, it does not stop the grinding motion itself.
Behavioral modification and stress management techniques are important components of a comprehensive treatment plan. Stress and anxiety are common triggers for bruxism, making practices like meditation, biofeedback, and cognitive behavioral therapy helpful for reducing the clenching habit.
Reducing consumption of alcohol and caffeine may also lessen symptoms, as these substances can affect sleep quality.
In cases of severe, persistent bruxism that has not responded to traditional methods, Botulinum toxin (Botox) injections into the masseter and temporalis muscles can temporarily relax the jaw muscles, reducing the intensity and force of clenching and grinding. These injections wear off after three to six months, requiring repeat treatments to maintain the effect.