Abstract
AIM: To evaluate dentinal defect development, this study compared three rotary systems used for root canal preparation, namely ProTaper Next (PTN), 2Shape, and Reciproc.
MATERIALS AND METHODS: Sixty first mandibular molars with two separated canals were selected and included in this study. The samples were divided into four groups (n = 15): Control, PTN, 2Shape, and Reciproc. The control group was left unprepared, and the remaining 45 samples were prepared using these three systems. The samples were sectioned perpendicular to the long axis at 3, 6, and 9 mm from the apex. Each slice was examined under a stereomicroscope at 20× magnification to evaluate the presence of dentinal defects. The images were analyzed using ImageJ software, and the data were assessed statistically using the Chi-square and Fisher's exact tests.
RESULTS: No cracks were observed in the control group. ProTaper Next, 2Shape, and Reciproc groups caused cracks development in 24, 11, and 40% of the samples, respectively. Reciproc system caused significantly more cracks at 3 mm level (p < 0.05). No statistically significant difference was observed among groups at the 6 and 9 mm levels (p > 0.05).
CONCLUSION: All three rotary file systems examined produced dentinal cracks, particularly at the apical third. ProTaper Next and 2Shape tend to produce fewer cracks compared to Reciproc.
CLINICAL SIGNIFICANCE: Although all motion kinematics tested in this study caused some degree of dentinal crack formation, the Reciproc system (R25) demonstrated a more destructive effect in the apical third of the root canal. In contrast, the PTN and 2Shape 25/0.06 systems were found to be safer options for root canal preparation in the mesial roots of first mandibular molars. How to cite this article: Nasiri K, Doychinova M, Wrbas KT. Comparative Evaluation of Dentinal Crack Formation Using Three Ni-Ti Rotary Systems after Root Canal Preparation: An In Vitro Study. J Contemp Dent Pract 2025;26(7):663-667.