D-RaCe files are intended to remove filling materials, such as gutta-percha, carriers, paste and resin-based materials.

Desobturation

"Desobturation" prior to "retreatment" : because access must be made, the entrance of the canal desobturated to reach inside the canal itself so that it could be properly retreated. Retreatment must be achieved because the first RCT failed or needs improvement.

Once desobturated, the canal will be retreated

In a number of cases, DR2 will reach Working Length. But in most cases 25/.04 can not be the final shaping instrument. Retreatment will then be made with the usual RaCe instruments till the adequate diameter at WL. All retreatments will mean an increased enlargement over first intention RCT - to remove the sealer and gutta remnants, cleaning and disinfecting, plus final three-dimensional shaping of the canal. Whatever the diameter, obturation will be made once a perfectly cleaned, disinfected, shaped canal is ready for obturation.