Different insertion angles of the rotary files during the canal shaping may influence the cyclic fatigue resistance (CFR). The aim of the present study is to evaluate the effect of different insertion angles on file’s static cyclic fatigue resistance at body temperature.
Methods and Material:
25 mm long Eighty new Neoniti (Neolix, Châtres-la-Forêt, France) files were used. The stainless-steel metal block was designed with four artificial canals having different insertion angles (0°, 10°, 20°, and 30°). The files were subjected to static cyclic fatigue procedure at simulated body temperature (35 ± 1 °C). The number of cycles to failure (NCF) were recorded.
Kruskal Wallis H test was performed to analyze the data at 95% confidence interval (P=.05). For #20.06 and #25.06 instrument, the 10°, 20° and 30° insertion angles resulted in decreased static fatigue resistance as compared to straight (0°) insertion angle (P <.05).
When the insertion angle increases, the static cyclic fatigue resistance (CFR) decreases. An inclined insertion into the canals decreases the cyclic fatigue resistance of the endodontic instruments.