Orthograde root canal retreatment of UL6

The patient was referred for assessment and treatment of the upper left first molar. Clinical examination revealed a large coronal restoration with signs of marginal leakage, together with a buccal sinus tract associated with the tooth. Following a clinical and radiographic examination, the diagnosis was established as a previously treated tooth with a chronic apical abscess. Both vertical and lateral percussion tests were negative, and the patient reported no pain on biting. Periodontal examination, however, revealed an isolated probing depth of 12 mm on the mid-buccal aspect of the tooth. All other probing depths around the tooth were within normal limits. Considering the clinical and radiographic findings, I decided to perform a nonsurgical root canal retreatment combined with a coronal…