- Patients with previous extensive restorations (e.g., amalgam or resin restorations, crowns), trauma or recurrent caries with pulp exposure
- Medically-compromised patients
- Swelling (sometimes)
- Sinus tract (sometimes)
- Large periapical lesions (sometimes)
- Pain severity may vary
- Continuous flow of pus or serous-like fluid
- Bad taste in mouth (drainage from sinus tract)
- Thoroughly assess the patient’s medical history: diabetes mellitus, bleeding disorders, history of radiation therapy and trauma.
- Perform a complete extraoral and intraoral examination:
- Examine for sinus tract inside or outside the oral cavity. If present, trace radiographically.
- Examine for swelling and periodontal pocketing.
- Examine teeth for caries, broken down restorations, crowns with open margins or recurrent caries.
- Perform pulp tests (hot, cold and electric) on the tooth in question and surrounding teeth to ensure they are not contributing to the problem.
- Perform a radiographic examination:
- periapical radiographs to check for periapical (PA) pathology and periodontal problems (Fig. 1)
- bitewing radiographs to check for dental caries
- Perform a radiographic examination to investigate:
- recurrent caries
- pulp exposures
- widened periodontal ligaments
- external and internal resorption
- length accuracy, perforations, strip perforations, or possible additional canals after the initiation of treatment
- pathology in the area around the teeth or in the maxillary sinus
Based on the clinical and radiographic examinations and the patient’s medical history, a diagnosis of necrotic tooth with unstoppable drainage is determined.
If the patient presents with a fluctuant swelling, consider doing an incision and draining prior to initiating treatment. Then begin instrumentation.
- Perform a more thorough cleaning and shaping of the canal spaces to ensure that all necrotic materials have been removed.
- Verify length determination (apex locator and radiographs) to ensure that over-instrumentation did not occur. Special care should be taken near the maxillary sinus, since over-instrumentation can lead to persistent drainage.
- If a strip perforation or perforation is noted, repair immediately with MTA or equivalent material. If unable to perform this procedure, refer the patient to an endodontist.
- Irrigate with NaOCl and leave in the canals and chamber for 10–15 minutes. Dry and place Ca(OH)2 in the canals and close, if drainage stops.
- Use negative pressure irrigation, if available.
- If all else fails, leave the tooth open, reappoint the next day, lightly instrument, irrigate and dry, and close the canal.
- In cases where there is a large PA radiolucency associated with a necrotic tooth and the drainage continues, both conservative and surgical endodontic treatments may be required (Fig. 2). Refer to an endodontist if uncomfortable dealing with this situation.
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