A non-vital tooth refers to a tooth that has lost its vitality or the ability to sense stimuli due to damage or infection of the dental pulp, which contains nerves and blood vessels. Here's what you need to know about non-vital teeth:

1. Causes: Several factors can lead to a non-vital tooth, including severe tooth decay, traumatic injury, deep dental fillings, or extensive dental procedures. When the dental pulp becomes infected or damaged beyond repair, the tooth may lose its vitality.

2. Symptoms: Common symptoms of a non-vital tooth include persistent toothache, sensitivity to hot or cold temperatures, swelling or tenderness around the affected tooth, discoloration (darkening) of the tooth, and the presence of a dental abscess or pus.

3. Diagnosis: Your dentist will perform a thorough examination, which may include X-rays, to assess the condition of the tooth and determine if it has lost its vitality. They will also evaluate your symptoms and medical history to make an accurate diagnosis.

4. Treatment: Treatment for a non-vital tooth typically involves root canal therapy. During this procedure, the infected or damaged dental pulp is removed from the root canals, and the canals are cleaned, shaped, and filled with a biocompatible material to seal them and prevent reinfection. In some cases, additional treatments such as a dental crown may be recommended to restore the tooth's strength and function.

5. Prognosis: With proper treatment, most non-vital teeth can be saved and restored to full function. Root canal therapy has a high success rate and can relieve pain and discomfort associated with the infection while preserving the natural tooth structure.

If you suspect you have a non-vital tooth or are experiencing symptoms such as persistent toothache or discoloration, it's essential to see your dentist promptly for evaluation and treatment. Early intervention can help prevent further complications and preserve the health of your smile.