Caucasian patient, male, 35 years old, was referred by a colleague for evaluation and possible endodontic surgery in tooth 15, with endodontic treatment performed and intraradicular retainer installed. On clinical examination, a well-adapted prosthesis on the tooth and the presence of scar tissue in the periapical region of tooth 14, possibly related to a fistula originated from an endodontic infection of this tooth, recently treated.