Mechanical properties of a new and improved nickel-titanium alloy for endodontic use: an evaluation of file flexibility

Objective. A new manufacturing method to produce more flexible and resistant NiTi endodontic instruments has been recently developed. The purpose of the study was to determine whether this new manufacturing method produces NiTi instruments (TF) of superior flexibility. Study design. Ten .06 size 25 prototype (TF) instruments (Sybron Endo) and ten 06.25 ProFile instruments (Dentsply-Maillefer) were evaluated for stiffness on bending. Test procedures strictly followed ANSI/ADA Specification No. 28. Bending moment was measured when the instrument attained a 45 bend. All data obtained were recorded and statistically analyzed using an ANOVA test. Results. Statistical analysis of data showed that bending moments were significantly greater (P < .05) for ProFile instruments (mean value 59.06 g/cm), compared to the prototype instruments (mean value 35.60 g/cm), thereby confirming the increased flexibility of TF instruments. Conclusion. Results of the present study demonstrate the ability of the new manufacturing process to produce more flexible NiTi rotary instruments.