Generally, if the enlarging needle breaks off in the root and does not go beyond the apical foramen, it can be observed for a period of time, and if there is no pain or other symptoms, a filling can be done. It is also unlikely that something will go wrong in the future. However, if you feel uneasy, you can ask the doctor to take out the broken pin. If the hospital has enough technology and equipment, the possibility of taking out the broken pin is still quite high, but the treatment time will be longer.
If the enlarged needle breaks off and goes beyond the apical foramen, this is a more troublesome situation, and if there is pain and periapical inflammation, you can only consider apicoectomy, where an incision is made from the gums below the root of the tooth, and an inverted filling is done after removing the broken needle from below the root of the tooth.
Broken pins can be tricky to remove, and it depends on what the tooth is and where it is broken. A broken needle in an anterior tooth is better than a broken needle in a posterior tooth, and a broken needle in the upper part of the root canal is better than a broken needle in the apical part of the root. In other words, the further back the tooth is and the deeper the break, the less likely it is to be removed.
But don't worry too much, the instrument breaks in the root of the tooth happens all the time, the vast majority of patients have no symptoms, and after a week of observation and normal filling, there will be no problem later. Only a small number of patients will have problems. Moreover, removing broken pins requires specialized equipment such as root canal microscopes and ultrasonic instruments, and not every hospital has such conditions. You can discuss with the doctor to reduce your treatment costs, broken instruments such as this thing is not enough for medical malpractice, the doctor does not exist subjective error, you let him give you a clear medical record, if there are problems in the future and then look for him is.