A tooth commonly called “dead” has undergone a process known in dentistry as pulp necrosis, which is the death of the living tissue deep inside the tooth. Every tooth relies on its internal nerve, blood vessels, and connective tissue, collectively called the pulp, to function as a living structure and transmit sensation. When the pulp dies, the tooth can no longer respond to stimuli in the same way a healthy tooth does.
Understanding Pulp Necrosis
The dental pulp is a soft tissue located in the center of the tooth, running from the crown down through the root canals. This pulp contains nerves, which transmit sensations like pain and temperature, alongside blood vessels that supply the tooth with nutrients. Pulp necrosis is the final stage of a prolonged infection or inflammation, where the tissue inside the pulp chamber dies.
This tissue death is most often caused by deep tooth decay, where bacteria penetrate the enamel and dentin layers to reach the pulp. Trauma to the tooth, such as a severe blow, can also interrupt the blood supply to the pulp, causing it to die. Extensive dental procedures may also irritate the pulp to the point where it becomes irreversibly damaged and necrotic.
The Direct Answer: Sensation Loss
The direct answer to whether you can feel a dead tooth is that the tooth structure itself loses the ability to transmit sensation. Once the nerve tissue inside the pulp chamber has died, the tooth can no longer register typical pain signals. You will not feel sensitivity to cold or sweet substances in a necrotic tooth, which is a common sign of a live, inflamed pulp.
The loss of sensitivity to temperature, especially cold, can be one of the diagnostic signs a dentist uses to confirm pulp necrosis. Since the nerve is no longer viable, the tooth essentially becomes an inanimate structure unable to relay direct messages to the brain. This lack of sensation means the tooth is effectively numb to internal stimuli, although this does not mean all discomfort will cease.
Sources of Pain in a Necrotic Tooth
The confusing paradox is that a dead tooth can still cause intense pain, but this discomfort does not originate from the dead pulp itself. Instead, the pain comes from the live tissues surrounding the tooth root. When the pulp dies, the bacteria and toxic byproducts inside the tooth can leak out through the tip of the root and infect the surrounding bone and ligament.
The periodontal ligament is a specialized connective tissue that anchors the tooth to the jawbone, and it is rich in nerve endings. When infection and inflammation spread to this area, known as the periapical tissues, they trigger a painful response. This inflammation creates pressure on the ligament, which causes a necrotic tooth to feel sensitive to biting or tapping.
If the infection is left untreated, a periapical abscess, a collection of pus, can form at the root tip. This buildup of pus and inflammatory fluid exerts significant pressure on the jawbone, resulting in the severe, throbbing pain often associated with a “toothache”. Sometimes, the infection can create a small tunnel through the gum, called a sinus tract, to drain the pus, which may temporarily relieve the pressure but does not resolve the infection.
Necessary Steps After Identification
Identifying a dead tooth requires a professional dental examination, as symptoms can be misleading or even absent. Dentists commonly use thermal tests, which check the tooth’s response to cold, and electric pulp tests to determine if the internal nerve is still alive. X-rays are also used to visualize the bone around the root tip, looking for signs of infection or bone loss caused by the necrotic pulp.
Once pulp necrosis is diagnosed, prompt action is necessary to prevent the infection from spreading. The two primary treatment paths are root canal therapy or tooth extraction. Root canal therapy is the preferred method, involving the removal of the dead and infected pulp tissue from the inside of the tooth, followed by cleaning, disinfecting, and sealing the empty space.
If the tooth is too damaged to be saved or the infection is too extensive, extraction may be required. Leaving a necrotic tooth untreated poses a significant health risk because the infection can spread beyond the tooth, potentially leading to systemic issues or widespread bone loss in the jaw.