The life or death of a tooth depends on the health of the pulp. This network of nerves, blood vessels, and tissues occupies a hollow central chamber that extends from the crown of the tooth to its roots. The branch of dentistry that specializes in preventing and treating pulp problems is called endodontics.
The pulp nourishes the surrounding dentin via specialized cells called odontoblasts. These cells also relay sensory information, which is why injury or damage near the pulp evokes pain.
The pulp can be damaged in a number of ways. Among the most common are undetected tooth decay and advanced periodontal disease. Abrasion and erosion also can wear away the tooth’s hard outer layers, leaving the pulp vulnerable. The pulp may inadvertently be injured when your dentist grinds a tooth in preparation for a deep filling or restoration. And of course pulp trauma occurs when a tooth is broken or knocked loose.
Pulp damage is categorized as either reversible or irreversible. Its consequences can range from mild tooth sensitivity to complete nerve death of the tooth or even infection of the surrounding tissues. Symptoms vary according to the extent of the damage and can include pain, fever, prolonged sensitivity to hot or cold, swelling or tenderness of the gums, and cracked or discolored teeth.
Although tooth sensitivity is a hallmark of pulp injury, hypersensitivity does not in itself mean that the pulp is damaged. It’s a signal that the dentin has been exposed, allowing sensations of heat, cold, and irritation to reach the tooth’s nerves.
To reduce sensitivity, you might try one of the many toothpastes made for sensitive teeth. The effects of these products accrue over time, so it may take several brushings before you feel any relief. Also, active ingredients vary from brand to brand, so if one brand isn’t helpful, try another.
As an alternative, your dentist can apply a fluoride sealant to the crown of the tooth. The sealant covers the exposed dentin and should protect against pain. If the discomfort is extremely bothersome, your dentist may suggest that you apply the sealant to your teeth at home for several nights, using a specially made mouthpiece. If all else fails, root canal therapy can resolve the problem.
Pulpitis is an umbrella term for all forms of pulp inflammation. The pulp may be irritated by decay in the nearby dentin or by periodontal disease. Often pulpitis is reversible. In some cases, a natural coating of dentin will form over the pulp to shield it from the irritant, and the nerve will recover without treatment.
In situations where the pulp cannot heal itself, pulpitis is classified as irreversible. A bacterial infection in the pulp usually kills the nerve. The infection then spreads through the dead tissue in the root canal (the channels in the root portion of the tooth containing the pulp) and passes through the opening at the end of the root into the surrounding tissues. A cavity then forms in the alveolar bone and fills with pus. This pocket of infection is called an abscess. The pressure from the swelling tissue and the mounting pus forces the tooth slightly upward. At this point, severe pain, fever, weakness, and facial swelling are almost always present. Root canal therapy or removing the tooth are the only ways to prevent the infection from invading other parts of the body.
Source: Dental Health for Adults: A Guide to Protecting Your Teeth and Gums. Copyright © by Harvard University. All rights reserved.