parodontium

例句：

1. 1. He was a renowned dentist who performed many successful surgeries.
   他是一位著名的牙医，做过许多成功的手术。
2. 2.The dentist advised her to visit the clinic for further examination.
   这位牙医建议她去诊所做进一步的检查。
3. 3.The patient had a root canal treatment and recovered quickly afterward.
   患者进行了根管治疗，之后很快就恢复了健康。