Comparison of the effectiveness and dentin loss associated with three contemporary approaches for separated instrument retrieval: an in vitro study

The aim of this in vitro study was to compare three contemporary approaches for separated instrument retrieval: the Terauchi File Retrieval Kit (TFRK), the XP-endo Shaper combined with an ultrasonic system and the Meitrac Endo Safety System in terms of success rate, procedure time, dentin loss, and changes in canal volume. Sixty extracted single-rooted human premolar teeth were standardized and 5-mm-long nickel-titanium instrument fragments were placed in the middle third of the root canals. The specimens were divided into three groups ( n = 20). All procedures were performed under a dental operating microscope. Success was defined as the complete removal of the separated instrument and procedure time was recorded. Dentin loss was determined using a precision analytical balance and changes in canal volume were evaluated using cone-beam computed tomography (CBCT) and three-dimensional segmentation analysis. The success rate was 85% in the TFRK and XP-endo Shaper groups and 80% in the Meitrac group ( p > 0.05). The XP-endo Shaper group demonstrated a significantly shorter procedure time compared to the Meitrac group ( p < 0.05). Dentin loss was lowest in the TFRK group and highest in the Meitrac group ( p < 0.05). CBCT analyses indicated greater canal volume increase in the Meitrac group. These findings suggest that the XP-endo Shaper offers a faster approach, while TFRK provides a more conservative approach.