What causes root canal bleeding after retreatment, and what should be done about it?

Post-endodontic bleeding may be caused by normal reactions, coagulation disorders, root canal perforation, periapical periodontitis, or periodontal disease. It can be managed through re-filling, medication, repair or extraction, and periodontal treatment. If abnormalities occur, prompt medical attention is recommended. Specific causes are analyzed as follows:

1. Improper root canal filling: Incorrect root canal filling may lead to bacterial infection within the canal, causing inflammation and bleeding in blood vessels at the apex. Management includes re-filling the root canal to ensure proper sealing of the filling material.

2. Coagulation disorders: Patients with coagulation disorders such as thrombocytopenia or deficiency of clotting factors may experience prolonged bleeding after endodontic treatment. In such cases, hemostatic medications should be used under medical guidance, including tranexamic acid injection, desmopressin tablets, or etamsylate injection.

3. Root canal lateral perforation: Lateral perforation occurs when improper instrument handling during root canal treatment creates a hole in the root wall, damaging surrounding blood vessels and tissues and leading to bleeding. In this situation, root canal treatment must be stopped immediately, and interventions such as surgical repair or tooth extraction should be considered.

4. Periapical periodontitis: This is a common complication following failed or incomplete root canal treatment. Inflammation and infection of the periapical tissues can cause vascular congestion and edema, resulting in bleeding. Re-treatment of the root canal is required to thoroughly remove infected materials from the canal.

5. Periodontal disease: Periodontal disease is an inflammatory condition affecting the tissues surrounding the tooth and may present with symptoms such as redness, swelling, and bleeding of the gums. If periodontal disease is uncontrolled prior to root canal treatment, it may contribute to postoperative bleeding. Treatment includes periodontal therapy such as scaling and root planing—removing dental plaque and calculus and smoothing the root surface to reduce bacterial accumulation, thereby controlling inflammation and preventing disease progression.

In daily life, patients should strictly follow their dentist's recommendations for regular follow-up visits and examinations to maintain dental health. Routine brushing and flossing help keep the mouth clean and reduce the risk of infection.