This invention relates to a root canal treatment instrument comprising: a needle extending in a rodlike form, comprising: working section made of a superelastic alloy extending from a distal end of the needle; and a shank extending axially between the working section and a proximal end of the needle, made of at least partially a non-superelastic alloy, and a handle attached to a proximal end of the needle and adapted to be manipulated by a hand of a dentist. The working section possesses flexible nature because of its superelastic alloy composition, whereas the shank possesses rigid nature because of its non-superelastic alloy composition.