Ultrasonic Technique For Removing Separated-Instrument In The Maxillary Molar

Introduction: The maxillary second molar often presents challenges during root canal preparation due to its posterior position,which increase the risk of instrument separation during preparation. Ultrasonic techniques combined with pre-bendable ultrasonic tips can effectively address this issue. In this case, a pre-bendable ultrasonic tip was successfully used to remove a separated instrument from the curved mesiobuccal canal of a maxillary second molar. Case description: A 31-year-old male patient completed root canal treatment one year ago. However, one month ago, the tooth developed mild spontaneous pain . Clinical examination revealed a large tooth-colored filling material on the occlusal surface of the upper left second molar. The tooth exhibited percussion sensitivity but no mobility, and the surrounding gingiva showed no signs of redness or swelling. A periapical X-ray revealed a slightly curved mesial-buccal root canal with a separated instrument inside. After discussing with the patient, a treatment plan was proposed involving the use of pre-bendable ultrasonic tips to remove the separated instrument. The patient provided informed consent, and the separated instrument was successfully removed. The root canal treatment was completed without complications. At the 3-month follow-up, the patient reported no discomfort. Discussion: Ultrasonic techniques combined with pre-bendable ultrasonic tips can effectively remove the separated instrument. Conclusion/clinical significance: There are many methods for removing separated instruments, but the appropriate approach for the affected tooth should be analyzed before treatment. Blindly using a separated instrument retrieval kit is not advisable.