root canal file with long handle

例句：

1. 1.The dentist used a root canal file to clean the patient's teeth.
   牙医使用一根根管钻来清洁病人的牙齿。
2. 2.The patient was given a root canal file for his toothache.
   病人被给了一根根管钻来治疗他的牙痛。
3. 3.The dentist explained how the root canal file works in removing decayed tooth tissue.
   牙医解释了根管钻是如何在去除腐烂的牙齿组织中工作的。