Question

For which of the following conditions is a retrofilling indicated?

A. A maxillary central incisor with an inadequate single-cone root canal filling and a 9 mm. diameter radiolucency at the apex. The crown has a simple composite
restoration.

B. A maxillary lateral incisor with a well condensed root canal filling that has caused postoperative pain and swelling for 14 days. The tooth was asymptomatic before placing the root canal filling.

C. A maxillary premolar with a post and coping restoration. The facial root canal filling is 4 mm. short of the apex which has a 2 x 3 mm. radiolucency. The lingual root canal filling is adequate and its apex is normal.

Answer 1

A retrofilling is indicated for Option A — the maxillary central incisor with an inadequate root canal filling and a 9 mm. diameter radiolucency at the apex, suggestive of an endodontic failure and likely periapical abscess.

Step-by-step explanation:

A retrofilling is typically indicated for a tooth when nonsurgical retreatment is not possible or is unlikely to be successful. For instance, if there's a complex root canal anatomy, such as an irregular root shape or blockage that cannot be addressed with retreatment, a surgery might be needed. In the options provided, a retrofilling would be indicated for the maxillary central incisor with an inadequate single-cone root canal filling and a 9 mm. diameter radiolucency at the apex (Option A). The radiolucency suggests a possible presence of a periapical abscess or cyst associated with previous endodontic failure. Since the other cases do not mention such complications, Option A is the most likely indication for a retrofilling where a surgical approach to address the endodontic failure and bone healing is required.