《新唐书·列传·卷一百二十九》
不一会儿，见他的牙齿全都又焦又黑。他看看左右，叫拿来铁如意把牙齿都敲掉了，藏在带子里，拿出药来敷在断牙上，过了些时，牙生长出来，又整齐又洁白。
乃寝。顷视齿燋缩，顾左右取铁如意击堕之，藏带中，更出药傅其断，良久，齿已生，粲然骈絜。
After a while, I saw that his teeth were all burnt and black. He looked around and asked for an iron Ruyi to knock out all his teeth, hid them in his belt, took out the medicine and applied it to the broken teeth. After a while, the teeth grew out again, neat and white.