Cyclic fatigue resistance of two nickel-titanium instruments in different curving angles: a comparative study

The cyclic resistance of ProTaper Universal (size 25/08) and ProTaper Next (size 25/06) instruments was compared in artificial canals with different curvatures in this study. A total of 30 ProTaper Universal and 30 ProTaper Next instruments were divided into 6 groups (n = 10) and were operated into artificial canals with 3 different angles of curvature (45°, 60°, 90°). The canal length was kept consistent in this study. The number of cycles to fracture (NCF) was counted until file fracture occurred, at which point, the length of the fragment was measured. The data were analyzed statistically using ANOVA complemented by the Tukey test (p本研究针对不同弯曲角度的人工根管，比较了型号25/08的ProTaper Universal（普塔珀通用根管锉）与型号25/06的ProTaper Next（普塔珀Next根管锉）器械的循环抗折性能。共计30支ProTaper Universal器械与30支ProTaper Next器械被分为6组（每组n=10），分别置入3种不同弯曲角度（45°、60°、90°）的人工根管中。本研究严格控制所有根管长度保持一致。记录器械发生断裂前的断裂循环次数（NCF），并于断裂发生后测量断片长度。采用方差分析（ANOVA）辅以Tukey多重比较检验对数据进行统计学分析（p