Dental crowns, also called caps, fit over worn or damaged teeth. They can also serve a cosmetic purpose, restoring a discolored tooth to its former hue. Your dentist may fit you with a temporary crown to protect a damaged tooth while the permanent crown is being made. Depending on the material used to make them, the wear they get and the care they receive, permanent crowns last about 5 to 15 years.
Who Needs Dental Crowns?
Crowns serve many purposes in restorative and cosmetic dentistry. They are an integral part of providing support to weakened or broken teeth. Untreated dental problems can lead to jaw pain, headaches and bite anomalies that could do further damage to otherwise healthy teeth. The following purposes illustrate some of the conditions for which your dentist might recommend crowns.
Protecting soft or weakened teeth
Supporting extensively filled teeth
Restoring the appearance of misshapen, chipped or discolored teeth
Covering a dental implant
Rebuilding a tooth after a root canal
Creating a healthy bite
Types of Crowns
Dental crowns fall into three categories: full metal, porcelain fused to metal and porcelain. Your dentist will assess your dental health and discuss your options with you, but all three crown types have distinct advantages.
Precious metals have tremendous durability and are non-reactive. These characteristics make them a preferred material for dental crowns. Gold alloys are the most common metal for crowns, but some dentists also work in platinum or palladium alloys that have a silvery hue. Metal crowns offer outstanding longevity, but because they look nothing like natural tooth enamel, they are most often used for molars where they will not be as visible.
Metal and Porcelain Crowns
Porcelain fused to metal (PFM) conceals metallic surfaces under a ceramic layer that closely resembles natural tooth enamel. Because of their metal cores, these crowns reveal their underlying structure in strong light and lack the translucency of natural teeth. However, their color and texture make them well suited to capping front or back teeth. PFM crowns can cause more wear on opposing teeth.
Porcelain crowns have the most natural look and are generally indistinguishable from natural teeth. Due to advancement in ceramics they are every bit as strong as metal or PFM crowns. New CAD/CAM techniques allow dentists to create crowns in minutes, but the procedure is typically costly. Porcelain crowns made in this way wear at the same rate as natural teeth.
How Crowns Are Applied
Your dentist will give you a local anesthetic to numb the area before preparing teeth to receive crowns. Biting on carbon paper shows how your teeth meet, ensuring the crown will not interfere with your bite. After the bite impression, you will be fitted with a dental dam to protect the rest of your mouth from tooth dust and keep the restoration site dry. With a high-speed drill, the dentist will then reshape any teeth needing crowns. Reshaping may involve minor filing, or it could necessitate removal of more material to leave a peg-like anchor point for the crown. The amount of your natural tooth that must be removed depends on the type of crown you're getting and the reason for the restoration.
After shaping the tooth to prepare it for the crown, your dentist will take another bite impression. This step is essential to making the cap fit the remaining tooth perfectly. If you are getting same-day porcelain crowns, you have only a 20-minute wait. Metal and PFM crowns take more time to prepare; you will get a temporary acrylic crown and return in a few weeks to get the permanent crown fitted. In either case, the dentist will apply cement to the crown and press it into place.
If you get temporary crowns, ask your dentist about specific care requirements until the permanent crowns are ready. Some common precautions to take with temporary crowns include:
Chewing on the other side of your mouth
Avoiding caramel, toffee and other sticky foods that could loosen the dental work
Sliding floss from between the crowned teeth instead of lifting it free
Caring for Dental Crowns
Your new crowns look, feel and behave like your natural teeth, and they need the same care. Follow the brushing and flossing schedule your dentist recommends. Metal-based crowns may feel more sensitive to heat and cold initially but should adjust quickly. Contact your dentist if you notice the following concerns after receiving crowns.
Difficulty or pain when chewing
Pain in your head or jaw
Loosening or wiggling of the crown
Rough or jagged spots that could indicate a chipped porcelain crown