A fractured tooth typically causes pain or sensitivity, though the intensity varies significantly based on the severity and location of the damage. The discomfort you feel is a direct result of the fracture exposing the tooth’s sensitive inner layers to the harsh environment of the mouth. Understanding the nature of this pain often depends on learning how the tooth’s internal structure processes sensation. Even seemingly minor cracks require professional assessment, as they can compromise the long-term health of the tooth.
How Tooth Damage Triggers Pain Signals
The outermost layer of the tooth, the enamel, contains no nerves, so a fracture contained entirely within this layer may not cause pain. Beneath the enamel lies the dentin, a layer composed of millions of microscopic channels called dentinal tubules that extend inward toward the pulp. These tubules contain fluid and are connected to the central nerve tissue.
When a fracture breaches the protective enamel and exposes the dentin, external stimuli such as cold air, hot liquids, or sweet foods can cause rapid movement of the fluid inside these tubules. This phenomenon is known as the hydrodynamic theory of pain transmission. The sudden fluid shift stimulates the sensitive nerve fibers, or A-delta nociceptors, located at the dentin-pulp border, which the brain interprets as a sharp, fleeting pain.
Deeper cracks that reach the pulp, the tooth’s innermost chamber containing the nerves and blood vessels, can lead to a condition called pulpitis, or inflammation of the pulp. The rigid walls of the tooth prevent the inflamed tissue from swelling outward, causing a painful buildup of pressure internally that irritates the nerve. This irritation can result in a more persistent, throbbing ache that lingers even after the stimulus is removed. Furthermore, the movement of the fractured segments during biting can mechanically irritate the pulp, causing a characteristic sharp pain upon chewing, especially when releasing the bite.
The Spectrum of Pain Based on Fracture Type
Craze lines are the most superficial type of fracture, appearing as fine, hairline cracks that affect only the enamel. Since they do not penetrate the dentin, these lines are generally considered cosmetic and cause no pain or sensitivity. They are common in adult teeth and usually require no treatment.
A fractured cusp occurs when one of the pointed chewing surfaces of the tooth breaks off, often near a large filling. The pain associated with a fractured cusp is typically sharp and occurs specifically when pressure is applied to the weakened section or when the pressure is released. Because this type of fracture rarely extends deep enough to involve the pulp, the pain is usually localized and often subsides once the fractured piece is removed and the tooth is restored.
A fractured crown, often called a cracked tooth, is a fracture that begins on the chewing surface and extends vertically toward the root. The symptoms are erratic and often involve pain when biting, sensitivity to temperature changes, and difficulty locating the source of the discomfort. The pain is caused by the crack opening and closing under the force of chewing, which irritates the internal pulp tissue.
The vertical root fracture is one of the most serious types, starting in the root and moving upward toward the crown. This fracture may not cause symptoms initially, but it often leads to severe, deep pain as it allows bacteria to infect the pulp and surrounding bone tissue. Because this fracture is deep within the tooth structure, it frequently results in the tooth requiring extraction.
What to Do When a Tooth Fractures
If you suspect you have fractured a tooth, the immediate priority is to manage the pain and protect the tooth until you can receive professional care. Rinse your mouth with warm water to clean the area and remove any debris. If the area is bleeding, apply gentle pressure with a piece of sterile gauze for several minutes.
To reduce swelling and numb the immediate area, apply a cold compress to the outside of your cheek near the affected tooth for 10- to 20-minute intervals. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can effectively manage discomfort until you see a dentist. Avoid chewing on the side of the mouth with the injured tooth to prevent the fracture from worsening.
Contact a dental professional immediately, even if the pain is mild or intermittent, because a small crack can quickly progress into a major problem. Fractured teeth rarely heal on their own, and delaying treatment increases the risk of the crack spreading, leading to infection and the potential loss of the tooth. A dentist must assess the fracture to determine the best long-term treatment plan.