In some circumstances, the canal must be retreated. Therefore, the root filling material must be removed as much as possible before beginning the retreatment itself. 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 allowing 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. When the Rooter motor is used, memory programme no. 3 for D-Race DR1 should be selected.
- Application: : root canal desobturation