Root canal treatment technology is the most common and direct means of dental treatment of endodontitis, apical periodontitis, but also stomatologists clinically most applied treatment technology, the main principle is to remove the nerve and inflammation in the root canal, after disinfection with a special material will be completely closed, so that bacteria can not be circulated within the root canal, to achieve the purpose of the disease to get back to the good, as long as it is the perfect root canal treatment can basically As long as the perfect root canal treatment basically can do the tooth lifelong painless, normal use of the effect, but the human body is a very complex structure, the occurrence of disease is more varied, the same treatment means to solve the disease of all patients is obviously not very realistic, so in the actual application, there are often patients in the root canal treatment or after the treatment of pain, and some of the pain so that the doctor can not explain and helpless, and finally the patient can only helplessly The choice of extraction, while the doctor’s medical skills have doubts, and even some doctors and patients for this to the court, the purpose of writing this article is through the simplest language, will be their own 20 years of clinical experience in root canal treatment to do a summary, but also hope that patients with dental disease can be a more in-depth understanding of the complexity of this treatment, may not be detailed, for reference only.