Different doctors have different starting points and different opinions. Some doctors think that it is better not to kill the nerve, because the living pulp teeth are stronger and have a long service life, while some doctors think that it is risky to do braces without killing the nerve for decayed teeth, and it may cause complaints in case of pain in the future, because many patients do not understand that the doctor’s starting point is for the good of the patient, and only think that the doctor does not do a good job for him/her. Generally, we need to analyze this situation comprehensively, if the caries is not deep, after the restorative doctor’s trusted intra-oral doctor’s treatment, it is possible not to kill the nerve; but if the caries is too deep, it is usually necessary to kill the nerve. In addition, there is also a difference between front and back teeth, the front teeth are easier to treat without killing the nerve even if they are painful in the future, and can be treated without removing the braces. The back teeth are multi-rooted teeth, so it is more difficult to do the treatment without removing the braces, and some complicated treatment may require to remove the braces before doing the treatment. Multiple braces can sometimes cause difficulties in diagnosis and may be required to be removed before a clear diagnosis is made. The braces themselves cost more, and the removal of the braces will cost a lot of money for the restoration, which can easily lead to medical disputes, and many doctors would rather have the patient treated by killing the nerve first in order to avoid such disputes. Although the tooth will not hurt anymore after the nerve killing and thorough root canal treatment, it will easily become brittle after a long time. Older people generally pay more attention to the maintenance of dentures, will not bite hard things, and the possibility of repair again is also relatively small, generally do not do conservative treatment, or kill the nerve is more appropriate. Young and middle-aged patients understand this point can choose from their own perspective, if you do not consider the cost factor is certainly not to kill the nerve long-term results will be better.