A CASE REPORT OF REMOVAL OF A BROKEN INSTRUMENT FROM THE ROOT CANAL OF THE MANDIBULAR CENTRAL INCISOR UNDER MICROSCOPY

This is a report of a patient referred to Isozaki Dental Clinic for removal of a broken instrument in the mandibular central incisor. In addition to the fact that removal of a broken instrument from the root canal is difficult even under microscopy, difficult conditions were present in this case. The tooth concerned was the mandibular central incisor. Use of a dental mirror in the mandible under a dental microscope is generally considered difficult. The 5-mm-long broken instrument was located at the apex of the root canal, so the head of the broken instrument could not be identified under direct view. Despite these difficult conditions, the instrument was successfully removed from the root canal by assuming an ergonomically optimal posture with the finger rest placed close to the operating point, and using a modified ultrasonic tip to enable precision work.