What steps are involved in preparing a tooth for a crown?
Two visits to the dentist are usually needed.
At the first visit, the tooth to receive the crown is examined and prepared. X-rays are taken of the tooth and bone around it. If decay is found or there is a risk of infection or injury to the tooth’s pulp, a root canal treatment may need to be done first. (Pulp is the soft tissue inside your teeth containing blood vessels, nerves and connective tissue.)
To make room for the crown, the tooth to receive it is filed down across the top and sides. The amount of tooth filed away depends on the type of crown selected. All-metal crowns are thinner and don’t need as much tooth structure removed compared with all-porcelain or porcelain-fused-to-metal crowns. If too much tooth is missing, due to damage or decay, a filling material is used to “build up” enough tooth structure for the crown to cover.
After reshaping the tooth, a paste or putty is used to make a copy (also called impression) of the tooth that will be receiving the crown. Impressions of the teeth above and below the tooth to receive the dental crown are also made. This is done to make sure that the crown will not affect your bite.
The impressions are sent to a dental laboratory. The laboratory makes the crowns and usually returns them to the dentist’s office in two to three weeks. During this first office visit your dentist will make a temporary crown to cover and protect the prepared tooth while the permanent crown is being made.
At the second visit, the permanent crown is placed. First, the temporary crown is removed and the fit and color of the permanent crown is checked. If everything is okay, a local anesthetic (“numbing” drug) is sometimes used to numb the tooth and the new crown is permanently cemented in place.
Same day crowns made in a dental office. Crowns can also be made in a dentist’s office if your dentist has the equipment. Like the traditional way to prepare a tooth for a crown, the first steps are to remove decay and shape the tooth for a perfect fit inside the crown.
After these steps, the making of a crown is different. In this procedure, a scanning device (a “wand”) is used to take digital pictures of the tooth inside the mouth. The computer’s software creates a 3D model of the tooth. The digital design is sent to another in-office machine that carves the shape of the crown from a block of ceramic. This method of making a crown is called computer-aided design/computer-aided manufacturing (CAD/CAM). In less than 15 minutes, the crown is ready to be cemented into place.