ProTaper Universal retreatment files are designed to be used in sequence to remove filling materials, such as gutta-percha, carrier-based obturators and paste fillers. The three, easily identified files are designed for the different needs of unfilling the coronal third, the mid-third and the apical third – before canal reshaping. A working tip on the D1 file facilitates initial penetration. Each handle is no more than 11 mm for better visibility.
D1 has a cutting tip to facilitate initial penetration into the filling material. D2 and D3 both have non-cutting tips and are used to remove material from the mid and apical thirds, respectively.