To understand why a cracked tooth hurts, it helps to know something about the anatomy of the tooth. Inside the tooth, under the white enamel and a hard layer called the dentin, is the inner soft tissue called the pulp. The pulp contains blood vessels, nerves, and connective tissue.
When the outer hard tissues of the tooth are cracked, the chewing can cause movement of the pieces, and the pulp can become irritated. When biting pressure is released, the crack can close quickly, resulting in a momentary, sharp pain. Irritation of the dental pulp can be repeated many times by chewing. Eventually, the pulp will become damaged to the point that it can no longer heal itself. The tooth will not only hurt when chewing but may also become sensitive to temperature extremes. In time, a cracked tooth may begin to hurt all by itself. Extensive cracks can lead to infection of the pulp tissue, which can spread to the bone and gum tissue surrounding the tooth.
Although there are many surgical procedures that can be performed to save a tooth, the most common is called apicoectomy or root-end resection. When inflammation or infection persists in the bony area around the end of your tooth after a root canal procedure, your endodontist may have to perform an apicoectomy.
In this procedure, the endodontist opens the gum tissue near the tooth to see the underlying bone and to remove any inflamed or infected tissue. The very end of the root is also removed.
A small filling may also be placed to seal the end of the oral canal, and a few stitches or sutures are placed in the gum to help the tissue heal properly.
Over a period of months, the bone heals around the end of the root.
There are many different types of cracked teeth. The treatment and outcome for your tooth depends on the type, location, and severity of the crack.
Craze Lines: Craze lines are tiny cracks that affect only the outer enamel. These cracks are extremely common in adult teeth. Craze lines are very shallow, cause no pain, and are of no concern beyond appearances.
Fractured Cusp: When a cusp (the pointed part of the chewing surface) becomes weakened, a fracture sometimes results. The weakened cusp may break off by itself or may have to be removed by the dentist. When this happens, the pain will usually be relieved. A fractured cusp rarely damages the pulp, so root canal treatment is seldom needed. The tooth will usually be restored by your dentist with a full crown.
Cracked Tooth: When a cusp (the pointed part of the chewing surface) becomes weakened, a fracture sometimes results. The weakened cusp may break off by itself or may have to be removed by the dentist. When this happens, the pain will usually be relieved. A fractured cusp rarely damages the pulp, so root canal treatment is seldom needed. The tooth will usually be restored by your dentist with a full crown.
Early diagnosis is important. Even with high magnification and special lighting, it is sometimes difficult to determine the extent of a crack. A cracked tooth that is not treated will progressively worsen, eventually resulting in the loss of the tooth. Early diagnosis and treatment are essential in saving these teeth.
Split Tooth: A split tooth is often the result of the long term progression of a cracked tooth. The split tooth is identified by a crack with distinct segments that can be separated. A split tooth can never be saved intact. The position and extent of the crack, however, will determine whether any portion of the tooth can be saved. In rare instances, endodontic treatment and a crown or other restoration by your dentist may be used to save a portion of the tooth.
Vertical Root Fracture: Vertical root fractures are cracks that begin in the root of the tooth and extend toward the chewing surface. They often show minimal signs and symptoms and may therefore go unnoticed for some time. Vertical root fractures are often discovered when the surrounding bone and gum become infected. Treatment usually involves extraction of the tooth. However, endodontic surgery is sometimes appropriate if a portion of the tooth can be saved by removal of the fractures root.
Unlike a broken bone, the fracture in a cracked tooth will never heal. In spite of treatment, some cracks may continue to progress and separate, resulting in loss of the tooth. Placement of a crown on a cracked tooth provides maximum protection but does not guarantee success in all cases.
The treatment you receive for your cracked tooth is important because it will relieve pain and reduce the likelihood that the crack will worsen. Once treated, most cracked teeth continue to function and provide years of comfortable chewing. Talk to your dentist and/or endodontist about your particular diagnosis and treatment recommendations. They will advise you on how to keep your natural teeth and achieve optimum dental health.