Theoretically, the patient’s painful symptoms will be significantly relieved after the tooth is extracted for periapical infection, but in actual clinical work, there is no operation to extract the tooth because of simple apical infection, because each of our teeth is very important for us, bearing a very heavy chewing function. If it is not clinically necessary to extract a tooth, we must do our best to protect it. Especially in the case of periapical periodontitis, it is perfectly possible to preserve the tooth and there is no need to remove it. In general, for periapical periodontitis, whether acute or chronic, the first step is to go to a professional stomatologist, who will determine the position of the tooth and then apply a dental power system, that is, a high-speed turbine drill to open the pulp of the tooth, so that the inflammation of the pulp and the root tip can be fully drained through the open pulp hole, and after the drainage is clean, the tooth will be re-treated and protected by means of root canal treatment and crown restoration. This tooth can then continue to serve the patient’s chewing function for a long time without the need to remove it.