D-Race instruments are used to remove most of the old root filling material from the canals such
as gutta-percha, obturators or resin-based material. The D-Race set consists of two NiTi files DR1 and
DR2. The first instrument, DR1, has an active tip to allow engagement of the root filling material and is used in
the first millimetres of the coronal and straight part of the canal. Once the access is cleared with the DR1, the
second instrument, DR2, is used to reach WL. As this instrument is highly stressed, it is intended for single use.
The final shape is obtained with the iRace or BioRace sequences.

General information prior to removal of root filling material:
- Take two x-rays from different angles.
- Draw up an accurate assessment of the anatomy of the canal (very important).
- Find the entrance to the canal and access the root filling material.
- If necessary, prepare a 1-2 mm cavity with DR1 and pour in solvent to soften the root filling material. Use a warm plugger or ultrasound if necessary.