A root canal instrument includes a twisted strip having a titanium-nickel alloy or a plastics material. The strip has a cross-section having three exterior surfaces or four exterior surfaces. A coating is disposed on at least one exterior surface, the coating includes abrasive particles. A method of making the root canal instrument includes making a basic plate having a thickness of less than one millimeter, coating the basic plate with a coating having the abrasive particles； dividing the basic plate into longitudinally extended strips, twisting the strip to form a root canal drill bit having a cutting edge with abrasive particles disposed on the cutting edge.
