Dental Crowns
Dental crowns are the artificial appliances designed to repair the damaged teeth. It is a type of dental restoration which covered the portion of a tooth that lies above the gum line. In comparison, fillings are just fill in a portion of a tooth. Dental crowns covered the entire tooth structure and becomes the tooth's new surface. Porcelain ( dental ceramic), metal (noble or high noble), or a combination of either one, are materials of choice for dental crowns. Commonly the dental crowns are called “dental caps” or “tooth caps”. Dental crowns could last several years (5 and more), depending on the situation which the crown is exposed to. Good oral hyigene will be an important point for longer life of a crown. In some cases the dental crown might need a replacement: tooth decay has developed under the crown, poor esthetic, etc.
A crown can be used as a part of a bridge. Crowns can be made in a dental laboratory. Root canal treatment may be recommended before the placement of a crown. Sometimes dentist need to billed up a supportive foundation for a crown. The tooth/foundation may need to be trimmed to make room for a crown. Usually it takes 2-3 visits for crown placement. Due to a lack of cement or improper fit the crowns can fall out. Bring it to a dentist, it will be cemented back in place. The all-metal or PFM crowns are stronger and are better choices for back teeth than ceramic crowns. PFM and all-ceramic crowns are the same color as your natural teeth. They look just like normal teeth.
Preparing the tooth
The impressions are sent to the lab, where the crown is made. During that time, you will have a temporary crown placed. These crowns are usually made of plastic. They are made in advance by the laboratory or made by the dentist during your preparation visit. Then the dentist fits the temporary crown to your tooth.
These crowns are not meant to last for a long time. In some cases, however, a temporary crown can stay in place for a year or longer. If it needs to last longer, a lab-made plastic crown is best. It is stronger and will last longer than a temporary plastic crown that is made by the dentist.
Temporary cement is used to keep the crown in place. It is special cement that is designed to be weak. This allows your dentist to easily remove the temporary crown at each visit as your permanent crown is fitted.
At a second visit, your dentist will remove the temporary crown and test the permanent one. Sometimes crowns need additional polishing or glazing or some other adjustment before they are placed. Once the crown is ready, it's cemented to your tooth.
After a Crown
You shouldn't feel any discomfort or sensitivity after a crown is placed. However, if your tooth has not had a root canal it will still contain the nerve. You may therefore have some temporary sensitivity to heat and cold. If you notice pain or sensitivity when you bite down, contact your dentist. Usually this means that the crown is too high. This can be adjusted easily.
You may notice a thin, dark line next to the gumline on your crowned tooth if you look very closely in the mirror, particularly if you have a PFM crown. This dark line is the metal of the crown showing through and is normal.
A crowned tooth is protected from decay, except for the gum line. Your dentist may prescribe a high-fluoride gel for you to use every night to protect against decay. A crown does not protect against gum disease. You should continue practicing good oral hygiene.
Crowns, especially all-porcelain ones, can chip. This can sometimes be repaired in the mouth. Your dentist will etch the porcelain with acid and bond a composite resin to it to fix the chip. Porcelain repairs often don't last long. If there's a lot of chipping, you may need a replacement crown.
It's also possible that the cement could wash out from under the crown, but the crown does not fall out. Under these conditions, bacteria can leak in and cause decay. If your crown seems loose when you chew, or if you have an unusual odor around the tooth, discuss this with your dentist. Your dentist will check your crowns at your regular visits.
Crowns sometimes fall out. This can be caused by a lack of cement or an improper fit. If this happens, place the crown in a secure, zip-top plastic bag. Then bring it to your dentist to have it cemented back in place. If you are in no discomfort and your appearance is not affected, don't try to put the crown back in place yourself.
If you do need to put it back in your mouth, clean it well on the inside. Use a toothpick to loosen and remove any cement or debris that is stuck to the crown. A wet cotton swab can finish the cleaning. You can replace the crown temporarily using denture adhesive or temporary cement. This is sold in many pharmacies. Contact your dental office immediately and try to schedule a visit for the next day.
If you are away from home, seek a dentist in the area who can evaluate the problem. You may need a new crown or it may be possible to cement the old one back on the tooth.
