What You Should Know About This Common Dental Procedure
When do you need a crown the dental kind and what are your options for the material used to make that crown. Those are questions we are often asked by our patients, and we would like to give you the information you need to make an informed decision.
Let’s start by looking at the anatomy of a tooth, which can be divided into two basic parts – the root and the crown. In a person with healthy gums and bone, the root of the tooth is covered by the gums and bone. The part of the tooth that is visible in the mouth is called the clinical crown. A cemented restoration that partially or completely covers the outside of the clinical crown is referred to as a dental crown or cap.
When is a Dental Crown Needed?
There are a variety of situations that require a tooth to be restored with a dental crown. The following are the most common:
To protect a weak tooth from decay, from breaking or to hold together parts of a breaking tooth
To restore a severely worn down tooth
To cover and support a tooth with a large filling and one that doesn’t have enough tooth left
To hold a dental bridge in place
To cover a severely misshapen or severely discolored teeth
To cover a dental implant and as a cosmetic alteration
Types of Dental Crowns:
Crowns can be made out of a gold alloy, other metal alloys, stainless steel, all-porcelain/all-ceramic, composite resin, zirconia, or porcelain on the outside fused to metal or zirconia on the inside. In some cases, ceramic crowns can be made by milling the crowns out of blocks of porcelain in the dental office, without the need for temporaries or a dental laboratory. There are advantages and disadvantages to all of the types of dental crowns. Stainless steel crowns are preformed crowns used to cover baby teeth for children. Gold dental crowns have traditionally been the most durable and require less of the tooth to be removed or shaved down. The primary advantage of porcelain crowns is their esthetics, while newer types of ceramic crowns have become increasingly more durable.
The Dental Crown Procedure:
A dental crown usually requires two visits to the dentist – the first step involves examining and preparing the tooth, the second visit involves placement of the permanent crown.
First Visit: Examining and Preparing the Tooth.
At the first visit in preparation for a crown, your dentist may take a few X-rays to check the roots of the tooth receiving the crown and surrounding bone. If the tooth has extensive decay or if there is a risk of infection or injury to the tooth’s pulp, a root canal treatment may first be performed.
Before the process of making a crown begins, your dentist will anesthetize (numb) the tooth and the gum tissue around the tooth. Next, the tooth receiving the crown is filed down along the chewing surface and sides to make room for the crown. The amount removed depends on the type of crown used (for instance, all-metal crowns are thinner and require less tooth structure removal than all-porcelain or porcelain-fused-to-metal ones). If, on the other hand, a large area of the tooth is missing (due to decay or damage), your dentist will use filling material to “build up” the tooth to support the crown.
After reshaping the tooth, your dentist will use a paste or putty to make an impression of the tooth to receive the crown. Impressions of the teeth above and below the tooth to receive the dental crown will also be made to make sure that the crown will not affect your bite.
The impressions are sent to a dental lab where the crown will be manufactured. The crown is usually returned to your dentist’s office in two to three weeks. If the crown is made of porcelain, your dentist will also select the shade that most closely matches the color of the neighboring teeth. During this first office visit your dentist will make a temporary crown to cover and protect the prepared tooth while the crown is being made. Temporary crowns usually are made of acrylic and are held in place using a temporary cement.
Care for a Temporary Dental Crown
Because temporary dental crowns are just that – a temporary fix until a permanent crown is ready – most dentists suggest that a few precautions. These include:
Avoid sticky, chewy foods (for example, chewing gum, caramel), which have the potential of grabbing and pulling off the crown.
Minimize use of the side of your mouth with the temporary crown. Shift the bulk of your chewing to the other side of the mouth.
Avoid chewing hard foods (such as raw vegetables), which could dislodge or break the crown.
Slide flossing material out-rather than lifting out-when cleaning your teeth. Lifting the floss out, as you normally would, might pull off the temporary crown.
Second Visit: Receiving the Permanent Dental Crown
At the second visit, your dentist will remove the temporary crown and check the fit and color of the permanent crown. If everything is acceptable, a local anesthetic will be used to numb the tooth and the new crown is permanently cemented in place.
Is Getting a Dental Crown Painful?
The tooth being restored is numbed so that it isn’t painful during the crown preparation. This requires a shot in the gums of a local anesthetic. After the procedure is over and the anesthesia has worn off, the patient may feel some sensitivity with the temporary crown or some soreness in the gums around the tooth. The pain is very minimal though and shouldn’t last long.
How Long do Dental Crowns Last?
Dental crowns should last on average from 10 to 20 years. Crowns are still subject to fracture and cavities, so it is important to take extra care in brushing and flossing around crowned teeth to prevent them from needing replacement too often.
Does a Crowned Tooth Require Special Care?
While a crowned tooth does not require any special care, remember that simply because a tooth is crowned does not mean the tooth is protected from decay or gum disease. Your dentist will advise you on the proper care and maintenance of your dental crown which includes brushing and flossing twice daily and avoiding putting excessive force on it like biting on hard candy or ice. If you habitually grind your teeth, your dentist may recommend that you wear a mouth guard to protect your crowns while you sleep.
Sources: MedicineNet.com, WebMD.com