Loss of working length in curved canals with rotary nickel–titanium instruments and reciprocating files: A cone-beam computed tomography analysis

Aim: The aim of the study was to investigate the change of working length in curved molar root canals after preparation with rotary nickel–titanium instruments and reciprocating files. Materials and Methods: Thirty human-extracted maxillary and mandibular molars with curved roots were selected, with the help of a radiographic platform, a constant object sensor distance was arranged to take a digital radiograph of each tooth for determining the angle of curvature of the roots by Schneider's method. The teeth were divided into Groups I, II, and III based on the instrumentation, ProTaper group, Reciproc group, and control group, respectively. Preoperative and postoperative working length was determined and compared using cone-beam computed tomography. The difference was determined statistically using one-way anova analysis. Results: There was minimum loss of working length found when instrumentation was done with Reciproc files compared with ProTaper. Conclusion: Reciprocating instruments can be an effective alternative used in the preparation of severely curved canals.