Development of a novel canal preparation technique using the torsional fatigue profile of the ProTaper(TM) F2 rotary instrument - Info and Reading Options

The torsional fatigue profile of the ProTaper(TM) F2 instrument was determined using a reversible geared motor assembled according to the ANSI/ADA Specification No. 28. Ten instruments were tested at various deflection angles (DA). The mean number of cycles to fracture and standard deviation were determined for each DA. Based on the fatigue profile and a pilot study, the F2 was used with a reciprocating movement at 144° and 162° clockwise and 90° counterclockwise and compared to a standard ProTaper(TM) technique (SPT) via preparation of canals in resin blocks. The number of deformed and fractured instruments was recorded. Instruments cycled at larger DA demonstrated fewer cycles to fracture than those cycled at smaller DA (p< 0.001). Instrument deformation and fracture did not occur in any group. A torsional fatigue profile was generated for the F2. The novel technique was as safe as the SPT with respect to instrument deformation and fracture.