A tooth is referred to as being ‘dead’ when there is no longer any blood flow to it. Sometimes this is also known as a ‘non-vital tooth.’
A tooth has three layers – enamel, dentin, and pulp. The pulp contains the blood vessels and nerves.
Dead or dying nerves in the pulp can lead to a dead tooth. A dead tooth will also no longer have any blood flow to it.
A dead nerve in a tooth is sometimes referred to as a necrotic pulp or a pulpless tooth.
Once this happens, the tooth will eventually fall out by itself. However, it can be dangerous to wait for this to occur, as the tooth can become infected and affect the jaw and other teeth.
It is not always easy to identify a dead tooth just by looking at it. Only a dental professional will be able to diagnose it, which is why regular trips to the dentist are important.
There are, however, two main symptoms of a dead tooth that can help with self-diagnosis:
- change in color
A tooth that is dead or dying can lead to a varying level of pain, from almost non-existent to extremely painful. The dying nerve or an infection usually causes an increase in pain.
Some people wonder why they experience pain if the nerve is dead. However, the pain is not coming from inside the tooth but from extremely sensitive nerve endings around the outside of the tooth, called the periodontal membrane.
Bacteria and dead nerve remnants, or pus, builds up in the pulp cavity inside the tooth and puts pressure on the periodontal membrane, which can cause immense pain.
If there is an infection, it may turn into an abscess and produce other symptoms, including:
- bad taste
- bad smell
- a pimple on the gums
Change in color
If the tooth is dead, it will often get darker in color, and a person may notice a yellow, gray, or black discoloration.
A change in color usually occurs because the red blood cells are dying. This is a very similar effect to bruising.
The discoloration will usually happen if a dead tooth goes untreated and will increase over time.
There are two main causes of a dead tooth: tooth decay and tooth trauma.
Tooth decay begins on the outermost layer of the tooth, but over time it can cause cavities that penetrate into the deeper layers.
If these cavities are left untreated, they can eventually reach the pulp and create a pathway for bacteria to enter the tooth and cause the nerve to die.
The healthy pulp will have an inflammatory response to the bacteria to try and fight off the infection, but the white blood cells can only hold it off for so long.
The pressure inside the pulp will increase, cutting off the blood supply, starving the nerve, and killing the pulp. This can cause intense pain.
If there is a physical trauma to the tooth, such as from a sports injury or a fall, then the blood vessels can burst, or the blood supply to the tooth may be cut off.
Eventually, because there is no blood flowing to the tooth, the nerve and other living tissues inside the pulp will die.