In fixed denture restorations, after the tooth preparation, a temporary crown is usually made for the abutment teeth as a temporary restoration. In order to facilitate the removal of the temporary crown later, a temporary bonding material (usually zinc oxide or modified zinc oxide) is usually used. However, due to their slightly poor bonding properties, temporary crowns tend to fall off. Many patients do not care much about it, and as a result, the process and effect of wearing the crown is affected during the follow-up visit, causing unnecessary trouble. The role of temporary crowns: 1, temporary restoration of part of the chewing function: generally do not recommend patients to chew with temporary crowns, but for patients with more missing teeth, can still play a certain chewing function. 2, restore aesthetics: especially in the case of fixed restorations of anterior teeth. 3.Protection of prepared abutment teeth: On the one hand, if the abutment teeth are living pulp, they can be protected from hot, cold and chemical stimulation, which is beneficial to the pulp health and reduces the patient’s pain. On the other hand, even in the case of root canal treated abutment teeth, the dentin and pile nuclei can be prevented from receiving oral bacteria and food stains, which facilitates the adhesion of the denture. In addition, zinc oxide as a temporary bonding material has the effect of pacifying the pulp. 4. Protection of the gums: This role is particularly easy to overlook by patients and some doctors. In the case of fixed restorations of anterior teeth and premolar teeth, the doctor for aesthetic reasons, usually the shoulder (prepared in the tooth on the step-like edge, used and porcelain crowns against the place) prepared in the gum below, if not wearing a temporary tooth, the gum in a few days will be prepared to cover the shoulder, so that when wearing the tooth either the porcelain tooth does not fall on the shoulder, but pressed on the gum, or in order to The gums are removed or abraded in order to re-expose the abutment, causing bleeding and increasing the patient’s pain and chance of infection. Therefore, the temporary crown is a very important part of the fixed restoration process and one that can directly affect the quality of care. Neither the surgeon nor the turnout can be ignored.