A porcelain dental crown is used to cover a damaged tooth, for root canal therapy or to cover the post of an implant. A crown is placed to cover a tooth in order to aid it from further damage, to improve functionality and visual aesthetics. Crowns are also used to fill in a gap of a missing tooth. Similar to the purpose of a bridge, a crown is inserted where there was once a tooth, in order to prevent the patient’s bite from adjusting and causing further damage to the remainder of the teeth. Crowns can be made from a various assortment of materials ranging from porcelain, ceramin, zirconia, steel, resin, etc… We personally prefer porcelain dental crowns because they most closely resemble the aesthetic of a natural tooth & are durable to chipping and/or flaking.
Once your doctor recommends a porcelain crown, it will be several office visits before the final crown is placed.
1. Initial impressions & Shade– Alginate impressions of your upper and lower dental arches as well as impressions of the same tooth quadrant where the crown will be placed. The impressions of the tooth quadrant are taken in order to create a temporary crown while the alginate impressions are sent to the lab to make the normal crown. After the impression in taken, the doctor will match the color of your existing teeth to a share guide so that your crown aligns with your smile.
2. Preparing the Tooth– For the crown to fit perfectly, the original tooth which it will be covering needs to be prepared. Preparing the tooth for the crown involves removing specific amounts of the existing tooth, any filling material or tooth decay. After all matter is removed, a composite core is placed on the tooth. After the core is placed, the dentist will shape the tooth and reduce the biting surface until an adequate amount of the tooth and filling are removed. A crown is designed to securely fit the tooth, keeping bacteria out from underneath the vulnerable tooth structure.
3. Final Impressions– First, a polyvinyl siloxane impression material is applied around the tooth. Your dentist will then insert the impression tray with impressional material over the prepared tooth and ask your to bite down for 3-5 minutes in order for the impression to fully set. Once the material has set, the tray will be removed and examined for any air bubbles or voids.
4. Temporary Crown– After the tooth has been prepared for a crown, it is weak and susceptible to shifting. Any movement of the tooth will prevent the permanent crown from fitting correctly. Additionally, during the tooth preparation process, most of the tooth’s enamel is removed, leaving the tooth extremely sensitive to temperature and pressure. Placing a temporary crown will help prevent any shifts or discomforts.
5. Permanent Crown– Once the lab is complete with your permanent crown, your dentist will remove the temporary crown and will position the permanent crown. Checking for optimal contact fit between your crown and adjacent teeth is key. Once the fit is perfect, your dentist will isolate the tooth from any saliva or water, placed a bonding material around the prepared tooth, will your permanent crown with cement and place the permanent crown of your prepared tooth.
6. Adjusting Bite– Small adjustments are always necessary to the crown so that it fits perfectly.
The average life expectancy of a crown is anywhere from 5-15 years. As with any dental procedure, taking optimal care of your teeth with allow the crown to last a lifetime. Making sure to brush and floss at least 2x a day. Make sure to avoid hard items such as nuts or candies. They can cause excess wear to the teeth and increase the chances of damage.