RESUMEN
AIM: The aim of this case report is to describe the removal of a fractured file in mandibular right first premolar through the application of an endodontic template to guide a trephine until the file. BACKGROUND: The fracture of an endodontic instrument is a rare complication that requires therapeutic management. Removal procedures often cause excessive dentine loss. To limit this inconvenience, several techniques describing the removal of fractured files in the coronal third of the canal have been proposed. The guide facilitates the use of the Zumax removal kit (Zumax Medical Co. Ltd., Suzhou, China). CASE DESCRIPTION: A 30-year-old patient was referred to dental office for the endodontic retreatment of his mandibular right first premolar. The tooth was painful to percussion and buccal palpation. The periapical radiograph showed a periapical lesion, a defective root canal treatment, and the presence of a fractured file. It was decided to use the Zumax kit in order to remove the instrument. By using digital implantology software, a guide was constructed with a tube to guide a trephine and achieve straight-line access. The trephine was later driven by the resin guide. After completing the drilling, the instrument was removed with the Zumax extractor and the canal was then prepared, disinfected, and filled. CONCLUSION: The current case describes the removal of a separated instrument by use of a new approach that is planned on computer software and guided by a resin guide. CLINICAL SIGNIFICANCE: The guided endodontic technique avoids excessive loss of dental structure and simplifies the procedure by reducing chair time and increasing the operator's confidence.
