NiTi K-files made of nickel-titanium alloy - very flexible and safe.
Their resistance to bending is around 10 times greater than the resistance of stainless steel instruments. They are recommended for treatment of curved root canals, which can't be treated with stainless steel instruments. There is no need to pre-bend NiTi K-files. Great flexibility of NiTi instruments decreases the tendency to straighten the root canal. The risk of wedging instruments or perforation of the root canal is lower.