The soft dentin is removed with a round bur and the root canal access is exposed (picture of another case).
A torpan drill is used to drill through to the apical third of the canal. It facilitates determination of the root axis and allows any canal filling material to be removed.
The Benex drilling must lie within the root canal. The drilling direction of the previous root canal drilling always has to be adopted, because the diamond-coated Benex drill can pass out of the root canal unnoticed.