ProTaper retreatment files are made of a nickel-titanium alloy and used to unfill root canals filled with gutta percha points, Thermafil obturators or, eugenol based soluble paste. Use in a constant rotation speed of 500rpm for removing gutta percha or Thermafil obturators, and 250-300rpm for removing zinc oxide eugenol based soluble paste (with the appropriate solvent). D1 has a cutting tip to quickly penetrate the coronal third of the tooth. D2 is made for the middle third of the tooth. D3 is made for the apical third of the tooth. D2 and D3 have a rounded tip to fit the tooth anatomy.