How many crowns do you have in your mouth? Most people are 32
The portion of our teeth that extends through the gums is called the crown of the tooth or natural clinical crown. Often people confuse the natural crown with an artificial crown or cap. Technically, most people have 32 crowns in their mouths.
When most people talk about crowns, they are referring to an artificial crown. When a natural tooth is badly decayed, is chipped or cracked, or has been filled and refilled multiple times with frequent failures, your dentist may recommend a crown. In this case, the crown is an artificial cover over our natural crown. Caries is removed and the remaining natural crown is reduced in size to make room for the new artificial crown. Local dental anesthesia is used for most teeth to make the procedure very comfortable and pain free.
Often too much tooth is missing due to original decay or fracture. The new crown needs a firm, solid base to rest on so your dentist can place a reconstruction first. The buildup is a restorative material that reshapes the remaining tooth to ideal contours, shape and size so that the new crown can ideally fit over the remaining tooth and buildup. The construction material is usually a composite that is bonded to the tooth.
Traditionally, after the tooth has been prepared, an impression or model of the area is taken and sent to a dental laboratory where the new crown is fabricated. The crown can be made of any combination of base metals (nickel), gold, palladium, and porcelain. Although less expensive, crowns made of common metals are not recommended. One of the main clinical advantages of the porcelain crown is that the X-rays will go through the crown and reveal any future decay. All metal or porcelain-fused-to-metal crowns block X-rays, often masking hidden cavities.
A lab-made crown can sometimes take several weeks to make. During that time, a temporary plastic crown covers the prepared tooth. This is cemented in place with a temporary cement to facilitate removal when the permanent crown is ready. Unfortunately, often the temporary crown becomes dislodged during the waiting period, causing discomfort and requiring a return visit to the dentist for re-cementation. This can be especially upsetting and embarrassing if you are dealing with a front tooth receiving a new crown or veneer.
New dental technology uses CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) to eliminate these drawbacks. After preparing the tooth for the crown using traditional methods, a high-quality impression is taken of the prepared tooth and the adjacent teeth in the arch. An impression of the relationship between the upper and lower teeth in that arch is also taken.
At this point the patient can return to work, home, run errands or relax in the dental chair while the new crown is made. Using lower power lasers, details of the prepared tooth, adjacent teeth, and opposing teeth are scanned into the specialized computer design center. Specialized proprietary software combines the digital scans with data about the shape and size of each tooth to create a near-ideal new crown. Using the mouse and specialized software tools, the new crown is made to be the perfect and ideal replacement crown for the damaged natural crown.
This data is digitally transferred to the 3D milling station where a solid block of porcelain is cut leaving the ideal replacement crown ready to be cemented or bonded to the prepared tooth, all within the same day.