Although the discomfort of the symptoms is very real, a cracked tooth can be a difficult dental problem to diagnose and pinpoint its location. Even a crack that is microscopic can cause a number of symptoms including pain when biting or chewing, sensitivity to hot or cold, or significant discomfort as biting pressure is released.
Chewing on a cracked tooth can be particularly uncomfortable. This is because pieces of the tooth may move and irritate the dental pulp. Eventually this repeated irritation can cause permanent damage to the pulp. The tooth may then consistently hurt and pulpal involvement may worsen. Continued irritation coupled with bacterial contamination seeping in through the crack can lead to a dental infection which can spread from the tooth to the surrounding bone and soft tissues.
Treatment of a cracked tooth depends on the extent of the crack and the degree of pulpal involvement. Symptomatic cases that receive root canal treatment and crowns before the crack propagates too far have a favorable prognosis. Teeth that are considered restorable are those where the crack is confined to the crown portion of the tooth. Complete vertical root fractures have a poor prognosis.
Types of Cracks
Craze lines are shallow cracks that only affect the outer enamel of your teeth. They are common in adults and are most often merely regarded as a cosmetic imperfection.
Cusps are pointed or rounded eminences on the chewing surfaces of your teeth. When a cusp for whatever reason (habits, trauma, decay) becomes weakened it can fracture. Chewing with a fractured cusp can cause the movement of the cracked portions of the tooth producing discomfort. At some point the broken portion of the tooth may break off itself or is removed by the endodontist. If the fracture did not extend deep into the tooth and cause pulpal involvement, a root canal therapy may not be required. In this case a dental crown or onlay may be sufficient to restore the tooth.
When a crack extends vertically from the chewing surface toward the root, it is referred to as a cracked tooth. In some cases the crack may extend below the gum line into the root. Although a cracked tooth is not completely separated into two pieces damage to the nerve is common. Typically, a root canal treatment is needed to treat the involved pulp in a cracked tooth. Following the root canal the treatment of choice to splint the two halves of the tooth together and prevent further migration of the crack is a full coverage crown.
Although, it is sometimes difficult to determine the extent of the crack, especially when it occurs under a filling or crown, early diagnosis is important. A cracked tooth that is not treated will progressively worsen and may reach the Split Tooth stage resulting in an unfavorable prognosis for the tooth.
Left untreated a cracked tooth can worsen with the crack extending down to the root surface. In a split tooth the crack completely divides the tooth into two distinct segments. The position and extent of the crack determines whether any portion of the tooth can in fact be saved. Only if sufficient tooth structure remains, it might be possible with the help of a root canal to preserve the tooth.
Vertical Root Fracture
A vertical root fracture is a crack that begins in the root of the tooth and extends toward the chewing surface of the tooth. Since they may not manifest overt signs or symptoms, they can go unnoticed for some time. A vertical root fracture is often discovered only when the surrounding area becomes tender or infected. Most frequently, a tooth with a vertical root fracture will require extraction. However, in some situations the tooth may be saved with an endodontic procedure and surgically removing the fractured portion of the root.