In the daily practice of dentistry, it is common to encounter patients who come to the clinic with a toothache, whose teeth not only hurt when exposed to cold or heat, but also sometimes have severe pain at night or even have difficulty sleeping. After a diagnosis, the doctor will usually say, “You need to kill the nerve in this tooth.” You may also hear the doctor say, “Your tooth needs a root canal”. So what exactly is a “nerve kill” and a “root canal”? What is the difference between them? Why do we need to use such treatment to relieve toothache? To answer these questions, we must first talk about the structure of the tooth. Our teeth can be described as “strong on the outside, soft on the inside”. The outer layer of the tooth is very hard and wear-resistant, but inside this “strong exterior” is a cavity with many blood vessels and nerves, which is the “weak interior” of the tooth. This is the “soft inner” part of the tooth. We call this soft inner tissue the “pulp”. When the pulp becomes inflamed, it causes pain, which is called “pulpitis”. In the past, the treatment for this type of pulpitis was to drill the tooth open and use medication to “kill” the inflamed pulp inside the tooth to relieve the pain, which is commonly known as “killing the nerve”. This is commonly known as “killing the nerve”. It can be seen that the term “killing the nerve” refers to some of the early treatment methods. With the comprehensive innovation of the concept of treatment and the great progress of treatment technology, this treatment method has basically been eliminated. In modern times, the method of “root canal therapy” is commonly used. As we mentioned earlier, there is actually a cavity inside the tooth, which we call the “root canal system”. Compared to simply killing the nerve, root canal therapy not only kills the pulp in the root canal, but also removes the pulp from the root canal. “Root canal therapy is not only to “kill” the pulp in the root canal, but also to remove the pulp from the root canal, which is then thoroughly cleaned and strictly sterilized, and the root canal is tightly filled with artificial filling material. This is called “root canal treatment”. “Root canal treatment is a complex procedure and may require multiple visits for the patient to complete the entire treatment. However, this method maximizes the elimination of inflammation and prevents reinfection. Whether or not a root canal is done properly will largely determine the longevity of the tooth. Moreover, not only for pulpitis, but also for other diseases of the tooth (e.g. apical periodontitis, etc.) can be cured by root canal treatment. However, it is not easy for doctors to explain the process of root canal treatment in detail to their patients, and it is difficult for patients to fully understand the process. Therefore, sometimes doctors will use the more common term “kill the nerve”, just to make the patient can easily accept, while the actual treatment is still the “root canal” method. With the continuous popularization of oral health knowledge, the general public’s understanding of oral treatment gradually improved, I believe that the term “kill the nerve” will one day fade out of our field of vision, and standardized “root canal treatment” will be able to be more patients to understand and accept.