Unless a tooth is subjected to sudden trauma that exposes the nerve, such as a blow to the mouth, the process involved in causing damage to the nerve is usually a long one. In most instances, a tooth will need root canal therapy (RCT) due to infection related to dental decay. Decay begins on the surface of the tooth and slowly makes its way through the outer and inner layers until it reaches the nerve. Once the nerve is involved, options are limited to root canal therapy or extraction. When possible, saving the natural tooth is the most desirable choice.
When the nerve of the root has been attacked by decay, it begins to die. Bacteria cause an infection which often develops into the formation of an abscess at the root of the tooth. Stopping the infection and removing infected tissue from the tooth is critical. Root canal therapy cleans out the tooth and seals off the canal to protect it from further damage. In some cases where the infection is very severe, antibiotics may be prescribed to get the infection under control before RCT can be performed.