In Vitro Evaluation of Dentinal Microcrack Formation during Root Canal Preparations by Different Niti Systems

The purpose of this study was to compare dentinal microcrack formation while using hand ProTaper (PT), ProTaper and ProTaper Next rotary files. Forty single rooted teeth were selected. 10 teeth were left unprepared and served as control, and the remaining 30 teeth were divided into 3 groups. After preparation with the file system selected, roots were sectioned 3, 6, and 9 mm from the apex, and the cut surface was observed under steriomicroscope and checked for the presence of dentinal microcracks. Data thus obtained were compared by chi-square (χ) test. A two-sided (α=2) p value less than 0.05 (p<0.05) was considered statistically significant. Analyses were performed on SPSS version 17.0. The study concluded that control group did not show any microcrack. All file systems created microcracks in the root dentin, whereas the PT next file presented minimal dentinal microcracks and hand ProTaper presented highest percentage of microcracks.