Dental crowns, also referred to as caps, are placed over a tooth or dental implant, completely covering the tooth or dental implant 360 degrees to restore function, form, and color. Crowns are indicated when a tooth is cracked, chipped, broken, or decaying to restore functionality. Dental crowns can be made of materials such as metal, porcelain-fused-to-metal, resin, or ceramic (all porcelain). Dental crowns can last from 5-15 years, and can be replaced due to decay, fracture, and/or wear.
Types of Dental Crowns
There are four main types of dental crowns, including:
Porcelain-Fused-To-Metal Crowns- The porcelain is fused to a substructure of metal, often a white gold alloy. As you age, recession can occur. Recession can expose the metal substructure of porcelain-fused-to-metal crowns. This could give a very unnatural look to your teeth, as a dark line appears close to the gums.
Metal Crowns- There are multiple types of metal crowns, a yellow gold alloy and white gold alloy with precious metal or semi-precious metal, or a base metal alloy with metals such as nickel and chromium. It is best to avoid base-metal alloy crowns as people can have sensitivities to those metals. Patients who need crowns on their second molars (the last tooth in the arch) are the best candidates for metal crowns. Gold crowns are the longest lasting cast restoration known to dentistry. They are extremely strong, not prone to fracture, and they wear at the same rate as enamel.
All Resin Crowns- These can be the least expensive. They are very prone to breaking and wear down much faster than any other type of dental crown. These crowns can be used on teenagers to buy time until they are adults or on adults undergoing orthodontia (braces). You may want to discuss the pros and cons with your dentist if he/she offers you this type of crown.
All Ceramic Crowns- These dental crowns are also known as all-porcelain crowns since they are made of 100% porcelain. They are the best option for those who want to most closely match the natural look of their teeth, but there are a few drawbacks. They are more brittle compared to porcelain-fused-to-metal crowns or metal crowns. However, they are a great option for anyone who has metal allergies, and for esthetic areas of the mouth.
Who Needs Dental Crowns?
Reasons why a patient may need a dental crown include:
- Weak teeth need protection due to decay or worn out old fillings
- Restores a broken tooth to its proper working function
- Covers and supports a tooth that has more filling than tooth
- Holds dental bridges in place
- Covers dental implants
- Covers discolored or unattractive teeth
- All posterior teeth with a root canal need a crown in order to protect the tooth from fracturing and needing to be extracted
Anyone who has a damaged tooth is a possible candidate for a dental crown. Dental crown procedures are one of the basic types of procedures involved in general and cosmetic dentistry.
The Dental Crown Procedure
If you’ve never had a dental crown, it can be daunting. However, dental crowns are very common and routine. It typically takes two visits for a crown. In some cases, there exists technology that allows a crown to be prepared and cemented in only one visit (such as CEREC).
Prior to recommending a crown for a tooth, your dentist will examine the tooth, bone, nerve, and surrounding tissues both clinically and radiographically (with x-rays). From the exam, your dentist will indicate the ideal treatment for your tooth. In some circumstances, if the nerve of the tooth is infected and painful, or if the tooth has extensive decay that infiltrates the nerve of the tooth, a root canal may first be performed.
If a root canal is unnecessary the following steps will be taken. The soft tissue and tooth will be anesthetized and the area can be isolated with a rubber dam. The old filling and decay will be removed. After the old filling and decay is removed a build-up will be completed to replace the missing tooth structure. After the build-up is performed, the tooth will be prepared for the crown. Once the tooth is prepared, an impression will be taken of the prepared tooth. The dental assistant will make a plastic, tooth colored temporary crown. The temporary crown is cemented in place with temporary cement. The dental impression is sent to an expert dental lab technician who will fabricate the crown. The dental lab takes approximately 2-3 weeks to complete the process, which means that the patient will have the temporary crown for 2-3 weeks.
During the second visit, the dentist removes the temporary crown and replaces it with the permanent one. He or she will check to ensure it fits correctly, that it doesn’t affect your bite, and that it blends in nicely. If the patient and dentist agree on the appearance and feel of the new crown, the tooth can be numbed and the permanent crown is cemented.
Caring for Your Dental Crown
A dental crown needs to be taken care of similarly to your natural teeth. It is recommended that you continue your normal hygiene habits, brushing two times per day, flossing once per day, and seeing your dentist on regular intervals. Keep in mind that a crown or cap that covers the tooth in its entirety can still get decay in the future.
