Differential Diagnoses for Grey Discoloration of Endodontically Treated Teeth
Primary Differential Diagnoses
- Grey discoloration is a classic sign of pulpal necrosis in endodontically treated teeth, particularly when the endodontic treatment was incomplete or has failed 1
- This occurs even years after treatment if the root canal system was inadequately debrided or if reinfection has occurred 2, 3
- The grey color results from breakdown products of hemoglobin and necrotic tissue penetrating the dentinal tubules 1
- Inadequate coronal seal allows bacterial infiltration leading to recurrent infection and discoloration 2, 3
- This manifests as grey discoloration along with potential periapical pathology 2, 3
- May be accompanied by a parulis (gingival abscess) adjacent to the affected tooth 1
Clinical Evaluation Approach
- Obtain periapical radiograph to evaluate periapical tissues, quality of root canal obturation, and presence of pathology 2, 3, 4
- Assess for presence of parulis or gingival swelling suggesting active infection 1
Radiographic Follow-up Protocol
- For endodontically treated teeth showing discoloration, follow-up radiographs should be obtained at 3 months, 6 months, 1 year, and then annually for 3 years 2, 3, 4, 5
- This protocol allows assessment of periapical healing and detection of complications such as root resorption 2, 3