The dental pulp is a delicate, soft tissue located within the innermost chamber of the tooth, often mistakenly called the “nerve.” This core tissue contains blood vessels, nerves, and connective tissue, responsible for the tooth’s vitality and nourishment. Pulp therapy is a dental treatment specifically designed to preserve or treat a tooth that has internal damage or infection to this pulp tissue. The procedure aims to save the affected tooth, most commonly a primary (baby) tooth, allowing it to remain in place until it is naturally ready to fall out.
Why Dental Pulp Requires Treatment
The need for pulp therapy usually arises when the protective outer layers of the tooth—the enamel and dentin—are breached, allowing bacteria to reach the pulp chamber. The most frequent cause is deep dental decay, or caries, which gradually erodes the tooth structure until it penetrates the pulp tissue. When bacteria invade this space, it causes inflammation, a condition known as pulpitis, which can quickly lead to irreversible infection.
Traumatic injury is another common reason, such as a severe chip or fracture that exposes the pulp directly to the oral environment. Symptoms indicating pulp damage often include persistent, throbbing pain that lingers after the removal of a hot or cold stimulus. A patient may also experience spontaneous pain that wakes them from sleep, or they may notice localized swelling, tenderness, or a small pustule (abscess) near the gum line of the affected tooth. These signs signal that the pulp is infected or damaged beyond self-repair, requiring intervention to prevent the infection from spreading to the surrounding bone.
Types of Pulp Therapy Procedures
The specific type of pulp therapy chosen depends directly on the extent and severity of the pulp damage and infection. For instances where the damage is minimal and the pulp is only mildly irritated, procedures like an indirect or direct pulp cap may be used. In an indirect pulp cap, the deepest layer of decay is intentionally left behind to avoid exposing the pulp, and a medicated material is placed over it to encourage the pulp to heal itself.
When the infection has progressed, a more extensive procedure is required, most commonly a pulpotomy. A pulpotomy involves removing only the infected or damaged pulp tissue located within the crown portion of the tooth. The healthy pulp tissue remaining within the root canals is left intact and covered with a therapeutic dressing, such as mineral trioxide aggregate (MTA) or a formocresol agent, to maintain the vitality of the root. This procedure is generally performed when the infection is confirmed to be limited to the coronal part of the tooth.
A pulpectomy is performed when the entire pulp, including the tissue in the root canals, is infected or has died. This procedure involves the complete removal of all pulp tissue from both the crown and the root canals of the tooth. The canals are thoroughly cleaned, disinfected, and then filled with a resorbable paste, often a zinc oxide-eugenol (ZOE) mixture, which the body can safely dissolve as the primary tooth prepares to exfoliate naturally.
What to Expect During the Treatment
The procedure begins with the application of local anesthesia to ensure the area around the tooth is completely numb. The dentist will then typically isolate the tooth using a thin sheet of material called a rubber dam, which keeps the tooth clean and dry from saliva and bacteria during the procedure. After isolation, the dentist uses a dental handpiece to access the pulp chamber by carefully removing the decayed and damaged structure.
Once the pulp chamber is accessed, the specified amount of infected pulp is removed, depending on whether a pulpotomy or pulpectomy is being performed. The chamber is then cleaned and disinfected before the appropriate medicated material is placed inside to seal the area. Following the internal treatment, the tooth structure is restored immediately to prevent contamination. In pediatric dentistry, this often involves placing a pre-fabricated stainless steel crown over the tooth to provide full coverage, strength, and protection against fracture until the tooth is naturally lost.
How Pulp Therapy Differs from a Root Canal
Pulp therapy and root canals share the goal of saving a tooth with internal damage, but they differ significantly in application. Pulp therapy is overwhelmingly performed on primary teeth, aiming to maintain function only until the permanent tooth beneath it is ready to erupt. A traditional root canal, conversely, is reserved for permanent teeth.
The procedures also differ in scope and filling material. Pulp therapy, especially a pulpotomy, often preserves the vitality of the pulp in the roots, allowing the root to continue its natural life cycle. A root canal requires the complete removal of all pulp tissue, permanently sealing the root canal system with a non-resorbable material like gutta-percha. The resorbable filling materials used in primary-tooth pulp therapy are designed to dissolve harmlessly with the root structure, preventing interference with the eruption of the successor permanent tooth.