Extraction of the penultimate tooth requires a missing tooth restoration such as a dental implant or a fixed or removable denture. The penultimate tooth is the second molar, or the first molar if the wisdom tooth on that side has not erupted. This tooth is a functional tooth and needs to be restored after extraction, otherwise it will affect chewing, and also tilt the neighboring teeth and elongate the opposite jaw teeth. Restoration after extraction includes two types of methods, one is dental implants, the other is the production of dentures, including fixed dentures and removable removable dentures. Both types of restorations have their own advantages, and the doctor should be consulted to examine the specific situation and determine which method to use. Clinically, except for wisdom teeth, all other teeth need to be restored after extraction. Patients should go to a regular medical institution for restoration of missing teeth.