ProTaper: Design & Structure
ProTaper instruments are prepared from round nickel-titan wire by grinding. Cross-section of the instruments shows a triangular structure with three cutting points and no radial lands. ProTaper instruments have a non-cutting tip that guides the instrument in the canal and reduces the risk for ledge formation.
The convex triangular cross-section which reduces the contact area between the file and dentine. This greater cutting efficiency has been safely incorporated through balancing the pitch and helical angles. A progressively tapered file engages a smaller zone of dentine which reduces torsional loads, file fatigue and the potential for breakage. It clinically serves to improve flexibility, cutting efficiency and typically reduces the number of recapitulations needed to achieve length, especially, in tight or more curved canals.
