Comparison of fracture resistance of teeth with prepared protaper next, protaper gold, and hyflex CM rotary files

Preparation of the root canal system is a crucial step in treatment. Endodontically treated teeth differ structurally from healthy, untreated teeth. This can lead to cracking by creating pressure on wall, reducing fracture resistance tooth. Different designs, including cross-sectional shape, tip, taper, flute, radial land, helix angle, rake and pitch, influence outcome preparation risk fracture. The purpose this study was evaluate after using three different NiTi rotary files: ProTaper Next (PN), Gold (PG), HyFlex CM (HC). Thirty premolars with single straight were decoronated at cementoenamel junction, leaving 14 mm root. subjects divided into 3 groups. Group 1 (n = 10) prepared PN, group 2 PG, HC. After instrumentation irrigation, specimens subjected continuous vertical compressive force (crosshead-speed 2.28 mm/sec) order record (in newtons) until To describe surface characteristic dentinal preparation, section fragment apical third observed scanning electron microscope (SEM) 2500x magnification. micrographs analyzed according Hulsman’s method. results demonstrated that there statistically significant difference among (p 0.043). LSD post hoc test indicated HC showed higher < 0.05) compared both PN PG. In conclusion, file systems instruments generate comparison tend result increased resistance.