Targeted Endodontic Microsurgery for Palatal Root of Maxillary First Molar: A Case Report

<p> Purpose: Root-end surgery has clinical limitations in terms of accessibility. To overcome this difficulty, Targeted Endodontic Microsurgery (TEMS) has been proposed as one of the treatment options for surgical intervention. We performed TEMS for a chronic apical abscess caused by the palatal root of the maxillary first molar, which was not healed by nonsurgical root canal retreatment, and obtained favorable healing progress.</p><p> Methods: A 45-year-old woman presented with recurrence of swelling on the palatal side after initial root canal treatment of the maxillary left first molar. There was no percussion pain or tenderness on the tooth, but there was a sinus tract near the apex on the palatal side. Radiographic examination revealed periapical radiolucency on the mesiobuccal and palatal roots. The tooth was diagnosed as previously treated and with a chronic apical abscess. Although non-surgical retreatment was performed, swelling remained on the palatal side. Based on additional examination by dental cone-beam CT (CBCT), it was determined that the palatal root was indicated for root-end surgery. Only the palatal root canal was filled with MTA, and the other root canals were filled with gutta-percha and sealer. An impression of the maxillary dentition was taken to prepare a surgical template. Prior to root-end surgery, the acquired digital data was incorporated into a dental implant treatment planning support program, and a surgical template was designed so that approximately one-third of the apex of the palatal root could be removed with a trephine bur, and 3D printing was performed. Root-end surgery was performed by inserting a trephine bur from a predesigned position and drilling to a set depth to remove the palatal apex. After resection, the granulation tissue inside the cavity was scraped off, washed with saline, and then sutured.</p><p> Results: Follow-up was performed until 6 months after surgery. Periapical radiolucency of the palatal root subjected to TEMS decreased over time. In addition, periapical radiolucency of the mesiobuccal root decreased after the non-surgical root canal retreatment.</p><p> Conclusion: The palatal root of the maxillary first molar which did not respond to non-surgical root canal retreatment was successfully treated with TEMS. When performing TEMS, it is necessary to consider the cost and difficulties involved, but in applicable cases, it is less invasive and can be performed accurately in a shorter operating time than conventional root-end surgery from the palatal side. It is suggested that TEMS may be an option as a surgical endodontic technique.</p>