A root canal is a common dental procedure designed to save a tooth when its inner pulp becomes infected or damaged. During the procedure, the infected pulp is removed, the inside of the tooth is cleaned, disinfected, and then sealed. While effective, a treated tooth sometimes doesn’t heal as expected or becomes reinfected, leading to a failed root canal. Recognizing these indicators is important for timely dental attention.
Recognizing the Signs
Persistent or recurring pain is a primary sign of a failed root canal. This discomfort can be a dull ache, sharp pain when biting, or throbbing sensations that do not subside. Unlike temporary soreness after the initial procedure, this pain indicates an ongoing issue within the tooth or surrounding tissues.
Swelling and tenderness around the treated tooth or adjacent gum tissue can also indicate a problem. This swelling might be accompanied by sensitivity to touch. In some cases, a pimple-like bump, known as a fistula or abscess, may appear on the gums near the affected tooth, often indicating a draining infection.
Renewed sensitivity to hot or cold temperatures after the initial healing period can signal an unresolved issue. The tooth might also discolor, appearing darker or grayish, indicating internal damage or infection. A spreading infection can lead to broader symptoms like sinus issues, facial swelling, or pain radiating to the jaw or ear.
Common Reasons for Failure
Root canal failure often stems from persistent or re-introduced infection. This can occur if new decay develops, a crack or fracture forms, or a filling becomes loose, allowing bacteria to re-enter the tooth. Bacteria can also linger if the initial procedure did not thoroughly clean all infected material.
Complex internal tooth anatomy can contribute to incomplete cleaning. Very narrow or intricately branched canals might be missed during the first treatment. Even with advanced techniques, some hidden areas might harbor bacteria, leading to renewed inflammation or infection.
A cracked tooth or root developing after the initial procedure provides a pathway for bacteria to penetrate, compromising the sealed system. Similarly, a defective or improperly sealed restoration, like a crown or filling, can allow microorganisms to infiltrate and cause a new infection.
Seeking Professional Care
If you notice any of these symptoms, contact a dentist or endodontist promptly. Early detection and intervention can prevent serious complications and increase the chances of saving the tooth. Ignoring these signs can lead to infection spreading to surrounding bone or other teeth.
A dental professional diagnoses a failed root canal through a clinical examination, assessing symptoms and tooth condition. X-rays are crucial for revealing persistent infection around the root. A cone-beam computed tomography (CBCT) scan may also provide a detailed 3D view of the tooth’s internal structure and surrounding bone.
Treatment options for a failed root canal vary by cause and severity. Root canal retreatment involves reopening the tooth, removing previous filling materials, thoroughly cleaning and reshaping the canals, and then resealing them. If retreatment is not feasible or successful, an apicoectomy might be performed. This minor surgical procedure removes the root tip and any surrounding infected tissue. If other treatments are not viable, tooth extraction may be the last resort, with replacement options like a dental implant or bridge.