Abu Dawud said: I heard Ahmad b. Hanbal say: He was asked : How retaliation of a tooth is taken ? He said: It is broken with a file.
In-book : Book 41, Hadith 102
English translation : Book 40, Hadith 4578
41. Types of Blood-Wit (Kitab Al-Diyat)
باب الْقِصَاصِ مِنَ السِّنِّ