In this paper, based on the analyzes of helical characteristics, ideal geometric models of cutting edges and helical grooves of nose burr are developed.

This paper researched the rotary burs with special cutting edges,which is the newest lay out of such tools,it represents the international trend of development and advanced situation.

A new method with which the rotary burs can be machined in the simple NC grinding machine tool is introduced and the mathematic formulas are deduced.

Research on grinding modeling and forming theory for 4-axis gang control of rotary burrs;

Based on a 5 axis NC grinding machine for rotary burrs developed by the Tianjin University, the 4 axis NC grinding technology for rotary burrs is researched.

PURPOSE: To compare the removal efficacy of bacteria by four Ni-Ti rotary systems using an in vitro root canal model infected by Enterococcus faecalis.