the root of a tooth

• 牙根

the root of a tooth的用法和样例：

例句

1. The root is covered with a hard material called cementum.
   牙根上覆盖着的坚硬材料叫作牙骨质。
2. The Center of rotation located in trifurcation area.
   牙旋转中心位于三牙根分叉下方附近。