Introduction: The purpose of this study was to compare the cyclic fatigue of Reciproc (REC; VDW, Munich, Germany) and Reciproc blue (REB, VDW) with different angles of file access.
Methods: The cyclic fatigue resistance of 120 new REC R25 and REB R25 (REB) files was tested. Instruments were divided into 8 groups on the basis of the access angle inside the artificial canal tested (n = 15): groups 1, 2, 3, and 4 included REC tested at 0°, 10°, 20°, and 30°, respectively, and groups 5, 6, 7, and 8 consisted of REB tested at 0°, 10°, 20°, and 30°, respectively.