title: Cyclic fatigue analysis of Reciproc R25® instruments with different kinematics.
abstract: This study aimed to compare the cyclic fatigue resistance of Reciproc® instruments when used with different kinematics (150° counterclockwise (CCW)-30° clockwise (CW), 270° CCW-30° CW, 360° CCW-30° CW and continuous rotation). Various kinematics were tested in steel canals with a 3 mm radius and a 60° angle of curvature as follows (n = 20): 150° CCW-30° CW, 270° CCW-30° CW, 360° CCW-30° CW and 360° CCW (rotary motion). Reciproc R25® instruments were used until fracture occurred. The time to fracture was recorded in seconds. The data were statistically analysed using a one-way analysis of variance and Tukey's post-hoc tests (P = .05). The cyclic fatigue resistance of Reciproc R25® instruments used with various kinematics in decreasing order was as follows: 150° CCW-30° CW > 270° CCW-30° CW = 360° CCW-30° CW > 360° CCW rotary motion. The 150° CCW-30° CW reciprocating motion had the best performance in time to fracture. All reciprocating motions (150° CCW-30° CW, 270° CCW-30° CW and 360° CCW-30° CW) resulted in a longer mean duration to failure compared with the 360° CCW rotary motion.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Arslan
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Meltem
authors.initials: M
authors.lastname: Alsancak
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Ezgi
authors.initials: E
authors.lastname: Doğanay
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Ertuğrul
authors.initials: E
authors.lastname: Karataş
authors.affiliation: Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
authors.forename: İsmail
authors.initials: İ
authors.lastname: Davut Çapar
authors.affiliation: Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Ertas
mesh_terms: D001696:Biomechanical Phenomena; D004867:Equipment Design; D006801:Humans; D018915:Root Canal Preparation; D012399:Rotation
keywords: cyclic fatigue; kinematics; movement; reciprocation; root canal instrumentation; rotary