Causes of root canal failure
Root canal therapy is the main treatment for endodontic and periapical diseases by removing the inflamed pulp from the root canal and sealing it tightly. The root canal reduces adverse irritation of the gingiva and other tissues, preventing or promoting healing of periapical lesions.
The key to successful root canal therapy is the complete removal of infected or necrotic pulp tissue from the root canal system and the complete filling and sealing of the canal system, thereby treating and preventing endodontic and periapical disease. Endodontics has its limitations, with a success rate of 70 % to 94 %.
Because root canal therapy involves preparation of the tooth, drilling of the tooth, removal of the pulp, determination of the length of the root canal, preparation of the root canal, application of anti-inflammatory agents in the root canal, filling of the root canal, completion of the restoration, and post-operative visits, problems with any of these steps can lead to failure of the root canal.
Failed root canal symptoms
●Pain is a relatively common symptom. The patient is undergoing a root canal procedure, the gums are irritated and the tooth will have a temporary pain that lasts only a few days and the pain will gradually disappear. This is normal to the dentist. However, after the root canal is completed, the patient experiences severe pain in the tooth, which indicates that the root canal has not been completely treated and that cavity bacteria remain inside the tooth cavity.
●the appearance of pus in the gums. Apical abscesses are the root cause of the appearance of pus in the gums and are a distinctive feature of failed root canal therapy. Pain is felt before the tooth develops an abscess. After the tooth forms an abscess, the pain will be lessened. However, the gums can leak pus and if the patient does not go to the clinic in time, the apical abscess will develop into an apical cyst and the other teeth will slowly loosen or even fall out.
●Broken teeth are also a symptom of failed root canal treatment. The patient did not wear a crown after the root canal and did not take proper care of the tooth. The tooth is broken when too much force is applied during chewing. After the tooth is broken, the tooth cannot be retained. The patient’s tooth can only be removed and the tooth implanted.
●the dentist can also determine whether the root canal has failed or not by x-ray. In the x-rays, the periodontal membrane gap is widened and the extent of the apical lesion of the tooth is increased in comparison to the preoperative x-rays. These manifestations prove the failure of the root canal treatment.