The second molar extracted generally need to set 1 to 3 teeth, the specific need to be based on the alveolar bone conditions, wisdom teeth, personal physical fitness and many other factors to determine. 1. Alveolar bone conditions: after the second molar extraction, if after three months, the alveolar bone healing flat and plump, you can consider planting a second molar tooth for dental restoration; however, if the alveolar bone has been resorbed by inflammation resulting in the top of the alveolar ridge is low and flat, unable to meet the conditions of implant restoration, you need to consider setting 3 fixed bridges or set a movable prosthesis to repair. 2. Wisdom teeth: clinically, generally the second molar is missing, and there are wisdom teeth growing orthodontically, you can consider the first molar and wisdom teeth as the abutment for porcelain crown and bridge restoration for dentures; if there is no wisdom teeth or wisdom teeth tilted can not provide retention force, you need to consider the implantation of a tooth to repair. 3. Individual physical quality: If the individual is in good physical quality, a second molar can be implanted; however, if the individual has high blood pressure, high blood sugar, acute heart disease, etc., the missing second molar can only be repaired by inserting a removable movable denture. Therefore, after the extraction of the second molar teeth, the specific set of teeth need to go to the hospital stomatology department to comprehensively analyze the individual’s situation to determine.