If the last of the back teeth is a wisdom tooth, an implant is usually not necessary after extraction. If it is not a wisdom tooth, it is usually recommended to restore it after extraction, but it is not mandatory to choose dental implants. 1. The last of the back teeth may be a wisdom tooth, i.e., a third molar, which is extracted and generally does not need to be restored. 2. If it is not a wisdom tooth, such as the second molar, first molar, etc., it is generally recommended to restore it after extraction because it is a large tooth that performs the function of chewing. In some cases, the second molar can be left unrestored and only the short arch can be used for chewing. In addition if restoration is needed, dental implants are not a mandatory option. However, since it is the last posterior tooth and cannot be restored with a fixed bridge, a removable denture can be used. It is recommended to visit the hospital in time to find out whether and how to restore the teeth.