The resistance of ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium rotary instruments to cyclic fatigue was examined after their initial use in straight or curved canals in vivo. These instruments were rotated freely inside a steel phantom until separation. The number of rotations before failure and the lengths of the separated fragments were compared with data derived fro...

During root canal preparation procedures, the potential for instrument breakage is always present. When instrument breakage occurs, it leads to anxiety of the clinician and as well as a metallic obstruction of the canal which hinders further cleaning and shaping. Separated instruments must always be attempted for retrieval and if retrieval is not possible bypass should be tried. With the increa...

BACKGROUND and Overview. With the increased use of nickel-titanium (NiTi) rotary instruments for root canal preparation in endodontics, instrument fracture has become more prevalent. Extensive research has been conducted on the physical properties and mechanical characteristics of NiTi rotary instruments, as well as the factors that can contribute to instrument failure. NiTi rotary instruments ...

introduction: this study compared the cleaning efficiency of mtwo, race and medin nickel-titanium (niti) rotary instruments. materials and methods: sixty mandibular molar mesial roots were selected with angle curvatures between 25-35 degrees and divided into three groups; each containing 20 teeth. canals were prepared with the rotary files and irrigated with 2.5% naocl solution after each instr...

AIM To investigate the morphological changes in the apical third of the root canal after preparation with three techniques. METHODOLOGY Forty molar teeth were scanned using micro-computed tomography before and after instrumentation with: Group 1 - stainless steel K-files using the balanced force technique; Group 2 - stainless steel K-files (balanced force) and then refining the apical prepara...