Placing a temporary crown over the prepared tooth may seem like a cosmetic necessity, but in actuality, the temporary crown is very important for a number of reasons.
Some states and provinces allow dental assistants to make a temporary crown for your prepared tooth and in some cases the dentist will fabricate the temporary crown.
Using the small impression taken prior to preparing the tooth for the crown, the dentist or assistant will fill the impression tray with an acrylic resin material, in a shade appropriate for your case, and place it over the prepared tooth. Once the material has set, generally after one to two minutes, the impression is removed from your mouth. The temporary crown is shaped to fit your tooth and to remove any rough edges. Once it is ready, a temporary cement is used to secure the temporary crown onto your prepared tooth. The dentist will check to make sure your teeth bite together correctly and will ensure there are no rough or sharp edges around the temporary crown.
Temporary crowns are very important. Because your dentist has removed a substantial amount of tooth structure from the prepared tooth, the temporary crown acts as a barrier, keeping the prepared tooth in its place. Without a temporary crown, the prepared tooth can begin to shift. Any movement from the prepared tooth will prevent the permanent crown from fitting properly. In some cases, the prepared tooth can move so much that the permanent crown simply won't fit over the prepared tooth. If this happens, the final impression will be taken again and the crown will be sent back to the laboratory to be remade.
Temporary crowns also keep a vital tooth protected. If you had a root canal, there will be no feeling in the tooth. Vital teeth are a different case. Most of the enamel is removed from the tooth during the preparation stage, leaving exposed dentin. Without a temporary crown, your tooth would be extremely hypersensitive to temperature and pressure. A temporary cement that contains eugenol is generally used because of its calming affects on the nerve.
It is vital for you to follow the post operative instructions given to you for wearing a temporary crown. If the temporary crown does come off your tooth, call your dentist immediately and book an appointment to have it re-cemented.