When anterior teeth are missing, most patients are able to achieve timely restoration because of their aesthetic impact. In contrast, the loss of a single posterior tooth (excluding the loss of wisdom teeth) has not attracted sufficient attention. For such patients, the impact of a missing tooth on chewing food is not very significant, and the aesthetic impact of the missing tooth is very limited due to its backward position. Patients usually visit the clinic due to chewing difficulties caused by painful or excessive tooth loss in other teeth, when the best time and optimal conditions for restoration are often missed. The patient has to pay more time and cost to repair the tooth loss, therefore, the timeliness of restoring a single posterior tooth is very important.