Issue V10N01 | Year 2020 | Editorial Original Article | Pages 49 to 53
Objective: The aim of this study was to evaluate the influence of rotational speed on the cyclic fatigue resistance of Logic 25.06 rotary instruments (LOG 25.06; Easy Equipamentos Odontológicos, Belo Horizonte, Brazil). Methods: 20 Logic 25.06 instruments were used (n=20). The cyclic fatigue test was performed in an artificial canal made of stainless steel with 60° of curvature and 5 mm of radius. The instruments were activated 950 and 550 rotations per minute (RPM) until the fracture occurred. The time (in seconds) and the number of cycles to fracture (NCF) were measured. The data were statistically analyzed using One-way ANOVA and Tukey Test, the level significance used was 5 %. Results: the 550 RPM promoted a significantly higher time and NCF of LOG 25.06 in comparison with 950 RPM (P>0.05). The time increased in 95.9% and the NCF 27.25%. Conclusion: The results of this study showed that the rotational speed had a significant influence on the cyclic fatigue resistance of the Logic 25.06 rotary instruments. The 550 RPM rotational speed seems to be safer than 950 RPM, increasing the cyclic fatigue resistance of Logic 25.06.