A cracked tooth is a fracture extending from the chewing surface toward the root. Unlike bones, the hard outer layers of a tooth lack the necessary biological mechanisms for self-repair. Because a crack will persist and progress, professional dental intervention is necessary to prevent further damage and potential tooth loss.
Why Dental Cracks Do Not Self-Repair
The inability of a cracked tooth to mend is due to its unique biological composition. The outermost layer, the enamel, is the hardest substance in the human body, composed almost entirely of mineral crystals. Enamel is acellular, meaning it contains no living cells or blood vessels that could initiate a healing response. Once a fracture occurs, the body cannot generate new enamel to fill the gap.
The layer beneath the enamel is the dentin, which contains living extensions of cells called odontoblasts. In response to minor irritation, the pulp can form a thin defensive layer of reparative dentin. However, this limited ability cannot bridge a structural crack that compromises the tooth’s integrity. The dental pulp cannot rebuild the hard tissue layers, leaving the crack vulnerable to bacterial invasion and further splitting.
Classifying the Severity of Cracks
Dentists classify cracked teeth based on their location, depth, and direction, which influences the required treatment:
- Craze Lines: These are superficial hairline fractures confined solely to the enamel. They are common, harmless, and rarely require treatment beyond observation.
- Fractured Cusp: This involves a break of a tooth’s chewing surface, often occurring around an existing filling. It usually does not extend into the pulp chamber and is typically repairable with a crown.
- Cracked Tooth: This serious fracture begins on the chewing surface and extends vertically toward the root, potentially involving the central pulp. If the crack reaches the pulp, it causes severe pain and often requires root canal therapy.
- Split Tooth: This occurs when a cracked tooth progresses, separating the tooth into two distinct segments. A split tooth is generally not salvageable and requires extraction.
- Vertical Root Fracture: This type begins in the root and moves upward toward the chewing surface. These fractures are difficult to detect and often lead to infection of the surrounding bone and gum tissue, necessitating extraction.
Immediate Symptoms and Necessary Action
A cracked tooth often presents with subtle or inconsistent symptoms, making diagnosis challenging without professional help. A hallmark sign is intermittent pain upon chewing or biting, particularly a sharp jolt of pain that occurs when biting pressure is released. This pain happens because the crack momentarily flexes open under pressure and snaps back, irritating the sensitive pulp tissue inside.
Increased sensitivity to hot or cold temperatures is another common symptom, occurring as the crack allows thermal stimuli to reach the nerve. The pain may also manifest as a general, constant ache or swelling around the gum line. If any of these symptoms are present, seek dental care immediately, as delaying treatment allows bacteria to travel deeper into the tooth, risking infection and tooth loss.
While awaiting a dental appointment, avoid chewing on the affected side to prevent the crack from worsening. Over-the-counter anti-inflammatory medications, such as ibuprofen, can help manage pain and reduce swelling.
Long-term treatment depends on the severity of the crack. Minor fractures may be stabilized with a filling or bonding, while deeper cracks require a full-coverage crown. If the fracture has penetrated the pulp, root canal therapy is necessary; in the most advanced cases, extraction may be the only option.