1. The dentist examined the tooth root.
牙医检查了牙根。
2. The tooth root is embedded in the jaw.
牙根嵌入在牙槽中。
3. An infection reached the tooth root.
感染蔓延到了牙根。

A: I have a sharp pain in my tooth root.
A：我的牙根处有剧痛。

B: You should see a dentist to check the tooth root.
B：你应该去看牙医检查牙根。

1) 牙根

2) 牙齿根部

1. 牙根

e.g. The tooth root is damaged.
牙根受损了。

noun phrase

1. the part of a tooth that is embedded in the jawbone