There are multiple ways in which the nerves in a tooth can die. However, it most commonly occurs with a cracked tooth or a damaged, deep filling. Severe tooth decay which reaches the root pulp or a trauma to the jaw can also cause root death of a tooth. Bruxism, a condition where a person grinds their teeth and clinches the jaw, can also cause nerve damage to teeth.
I learned during my years of work in the dental field that most people do not realize how common it is for a tooth to crack. I also discovered most people think if the nerve is dead there is no point in having a root canal treatment on the tooth.
The most common place for a tooth to crack is at the corner of a large filling which has deteriorated over time. The crack may be only a hairline fracture, though in many cases a piece of the tooth will chip off. This usually occurs during eating due to the stress on the tooth from the force of the bite.
In a case where a piece of the tooth has chipped off and comes out of the mouth, usually with pieces of filling, the patient is well aware of the situation. The patient contacts the dentist for an appointment to have the tooth examined. However, with a hairline fracture it is possible for the patient to be unaware of the fracture for some time.
Normally when a tooth fractures, the tooth becomes heat and cold sensitive and the patient is made aware something is wrong. This sensitivity is caused by fluid filled with bacteria entering the tooth through the fracture. When the bacteria reaches the pulp of the tooth, the tooth begins to decay. If the bacteria reaches the root pulp, the damage can extend into the nerve. Usually the sensitivity is severe enough it is quite noticeable.
If a tooth fractures slowly over time it is possible for the heat and cold sensitivity to be mild and the patient not realize the tooth is cracked. Once the decay and nerve damage advances, the jaw bone can become infected and an abscess can occur.
Blunt trauma to the jaw area can damage the nerve pulp of a tooth. This can occur from a sports injury, altercation with another person, or an accident. It is possible for the trauma to damage the soft tissues of the mouth and cause nerve pulp damage with or without fracturing the tooth.
Bruxism can cause nerve pulp damage and nerve death through the stress on the tooth from the pressure exerted during the clinching and grinding. The fracture can occur during sleep and the patient be unaware it happened until the tooth exhibits symptoms.
Regardless of how the nerve pulp of the tooth became damaged, the result is the same. Seldom does the nerve recover. The recommended course of action is root canal treatment. The root canal procedure removes the damaged pulp from the tooth and allows the tooth to be sealed off. A tooth that has had a root canal treatment performed on it should have a crown placed over the tooth at least within six months of the treatment. The sooner the crown is seated, the safer for the tooth. Teeth which have had a root canal treatment tend to become brittle and can break apart, causing loss of the tooth. A crown seated over the tooth protects the tooth during the force of chewing.
Should you notice heat and cold sensitivity of a tooth, contact your dentist as soon as possible for an appointment.