Abstract
The physical properties of a Micro titane® K-file(MT)made of titanium alloy(Ti-6Al-4V)were compared with those of a conventional K-file made of stainless steel(MN and ZP).Resistance to torsional fracture, angular deflection and resistance to bending were examined according to the ISO standard 3630.The shape of the of tip the new files and fractured surface after the torsional fracture test were observed with a scanning electron microscope.In addition, the cutting area of the transparent curved root canal model treated by each K-file was calculated by a digital image analyzer.K-files No.15 to 40 in size were used.The tip of MT had a obtuse angle compared with that of MN or ZP.The resistance to the torsional fracture and bending was smaller in MT than in MN or ZP.Angular deflection in MN and ZP was proportional to file size, but obtained a definite value in MT.MT broke at right angles to the longitudinal axis after the torsional fracture test and it's surface was flat.The cutting area in MT was significantly smaller than that in MN or ZP.These findings suggested that MT was adapted to stricuture and curved root canal for flexibility.
