A tooth is made of three layers,

1. The strong, hard outermost enamel, 2. The intermediately tough dentin, and 3. The soft innermost pulp that contains the nerve ending, blood vessels and others cells which maintain the vitality of the tooth. When dental decay progresses, deep cavity form that may reach the pulp, exposing it to the exterior. Exposure of the pulp may also occur due to erosion/trauma (e.g., tooth fracture). Whenever the pulp is exposed, it develops inflammation and infection. For this, there are two treatment options: 1. Extraction of the tooth, 2. Retention of the tooth by root canal treatment. Such an endodontically treated tooth can function normally in the mouth. If untreated, the tooth develops pain, swelling, etc., and the infection can spread deeper into the bone.

When there is deep carious cavity reaching the pulp causing pulpitis or apical infection, fracture of tooth involving pulp or severe attrition of teeth leading to pulp exposure, root canal cleaning and filling are indicated.

Once decay reaches the pulp, it gets infected and the tooth must undergo root canal treatment. It involves complete removal of the pulp, cleansing and filling with inert material. Since pulp contains nerve endings which need removal in such a case, this is commonly referred to as nerve removal treatment.

No, a tooth with minimal destruction that is well restored does not fracture in normal usage. However, a grossly destroyed tooth may fracture if not protected by a metal crown.

Root canal treated teeth are not immune to decay; hence, proper brushing and oral hygiene maintenance is necessary to keep decay away.

As the nerve supply to the tooth is removed the tooth does not respond to heat, cold, etc., like other normal teeth but continues to function like other teeth in the mouth.

Once the pulp gets infected and adequate treatment is not carried out, there is a chance that the infection may spread to the underlying bone. In such cases, the infection forms an abscess in the bone (collection of pus). Such abscessed teeth can be saved by antibiotic therapy followed by root canal treatment. However, these patients require to follow this up regularly with X-rays and clinical check-ups until complete healing take place.

A tooth that is completely developed can be treated by routine root canal treatment. However, in young children, the roots of the teeth are still developing. In such children, it may be required to first undertake treatment to develop the root or close its open end and to then undertake the root canal treatment.

By doing root canal treatment, the cavity becomes wide and the tooth becomes brittle. To protect the tooth and avoid fracture of the tooth, crowns are placed. But when the height of the crown is small, the retention of it may be a problem.

Yes, it is done on primary teeth when the decay involves the pulp.

Depending on the involved tooth and infection status it may take multiple visits or can even be completed in a single sitting.