Case series: tooth retention 5 years after irretrievable separation of LightSpeedLSX instruments

Of 3,216 root canals treated endodontically at the Creighton University School of Dentistry from September 1, 2005, to August 31, 2007, with LightSpeedLSX instruments (LightSpeed Technology, Inc, San Antonio, TX), there were 12 cases of irretrievable instrument separation. More than 5 years after the separations, an attempt was made to contact the patients and assess for healing and tooth retention.

Third- and fourth-year dental students performed root canal procedures according to protocol from September 1, 2005, to August 31, 2007. A database was collected during the 24-month period recording cases with irretrievable LightspeedLSX separation. Efforts were made from July 2011 to December 2011 to contact the 12 patients for endodontic follow-up. Clinical and radiographic evaluations of healing were performed.

Of the 12 patients with irretrievable separations, 8 patients were contacted and 5 returned to Creighton University School of Dentistry for follow-up. All 8 contacted patients confirmed the presence of the root canal-treated tooth in question, and the teeth of the 5 evaluated patients were determined to be asymptomatic and functional. Radiographic analysis resulted in 2 teeth being classified as complete healing, 2 as uncertain healing, and 1 as no healing.

The 100% tooth retention rate and the lack of symptoms in 8 contacted (5 evaluated) patients 5 years after treatment suggests that long-term retention and functionality can occur after irretrievable instrument separation. Although tooth retention and functionality are desirable outcomes, radiographic findings may be indicative of inadequate periapical healing, thus requiring the clinician to evaluate whether additional treatment is necessary.