Comparative evaluation of dentinal crack formation after root canal preparation with Neoendo Flex and Mani Silk files: An in vitro study

CONTEXT: Neoendo Flex and Mani Silk are recently launched nickel–titanium (NiTi) rotary files. Dentinal cracks and file separation remain a critical problem in the endodontic domain. AIM: The aim was to evaluate and compare the incidence of dentinal crack formation after root canal preparation with Neoendo flex and Mani silk files. MATERIALS AND METHODS: Thirty-six extracted single-rooted premolars with straight, single root canals were selected for the study. The specimens were randomly assigned to three groups, with 12 samples in each group. The root canal preparation for the three groups was done with hand K-file, Mani Silk, and Neoendo Flex files, respectively, following which the specimens were horizontally sectioned at 3, 6, and 9 mm from the apex. Sectioned samples were viewed under a stereomicroscope to determine the presence or absence of dentinal cracks. The data were analyzed using one-way ANOVA and Chi-square test. RESULTS: Hand K-files and Mani Silk files produced a lesser number of cracks than Neoendo Flex files; however, the difference was not statistically significant among the three file groups at 3 mm and 6 mm (P > 0.05). A statistically significant difference between the groups was seen at 9 mm, where Mani Silk files produced fewer cracks than K files and Neoendo Flex files (P = 0.007). Overall, Neoendo Flex significantly produced more cracks than Mani Silk and hand K-files (P = 0.0029). CONCLUSIONS: Both hand K files and NiTi rotary instruments may cause dentinal cracks. Neoendo Flex files tend to produce more dentinal cracks than Mani silk and K-file.