齿龈溃疡

例句：

1. 1. He had a toothache and went to the dentist for treatment.
   他牙痛，去了牙医那里治疗。
2. 2. The patient was advised to rinse with salt water and apply a cold compress to the gums.
   病人被建议用盐水漱口并给牙龈敷冷敷。
3. 3. Gum disease is often caused by poor oral hygiene, so it's important to brush yourteeth regularly.
   牙龈病常常由口腔卫生不好引起，所以定期刷牙很重要。