Background and Aim: Root canal preparation with systems with the least chance of dentin cracking can increase the success of endodontic treatment. This study aimed to compare the One-Shape and XP-endo Shaper rotary files in the dentin crack incidence in the mesiobuccal canals of mandibular first molars.
Materials and Methods: In this experimental study, 60 eligible extracted mandibular first molars were randomly divided into three groups. The roots were prepared to #30 and 4% taper in the XP-endo Shaper group and #25 and 6% taper in the One-Shape group. The control samples were left intact. All groups were sectioned at 2, 4, and 6mm from the apex and examined under a stereomicroscope at 20× magnification. The incidence, location, and type of cracks were analyzed using chi-square test.
Results: There were no cracks in the controls. The crack percentage was 23.33% (n=14) and 11.66% (n=7) in the One-Shape and XP-endo Shaper groups, respectively, with a significant difference with crack-fee samples. There was no significant difference between One-Shape and XP-endo Shaper systems in the three sections (P>0.05). In the 2mm section, cracks were observed in six sections (10%) with One-Shape and four sections (20%) with XP-endo Shaper. In the 4mm section, cracks were observed in one section (5%) with One-Shape and five sections (25%) with XP-endo Shaper. In the 6mm section, cracks were observed in seven sections (35%) with One-Shape and one section (5%) with XP-endo Shaper.
Conclusion: The One-Shape and XP-endo Shaper systems were similar in crack incidence in the mesiobuccal canal of mandibular first molars.