Dental Crowns

What Is A Crown?

A dental crown is a type of cap that is placed on a tooth to modify the appearance of the natural tooth or to help protect the remaining structure of a tooth. Dental crowns are also placed on root canal treated teeth to prevent leakage of bacteria into the tooth. The crown creates a tight seal, which prevents microleakage and possible re-infection of the tooth. Dental crowns are also commonly used in full mouth reconstruction to provide the patient with a more natural bite and to replace worn natural crowns. This will allow the patient to chew and function more comfortably.

Natural tooth shade or shape modification can be easily accomplished with a crown because it is fabricated in a dental laboratory under controlled conditions. Dentists are able to correct alignment of a natural tooth and modify the shade to match the rest of the teeth.

Another common reason for crowning a tooth is to protect the weakened, remaining tooth structure and prevent tooth fracture. A tooth can be weakened by a traumatic event or normal wear. There are also other factors, which can weaken a tooth. These include: large cavity, large filling, an opening that was made during root canal treatment, defects within the structure of the tooth, fracture of a tooth.
Even though a dental crown in most cases does cover the majority of the tooth, good oral hygiene is crucial in its long-term success. Crowned teeth are at even greater risk for getting a cavity. This is due to potentially irregular transition from a natural tooth to the crown margin.

After fabrication, a crown is permanently cemented on to provide ideal esthetics and function

Purpose Of A Dental Crown

  • Replace missing tooth structure
  • Improve esthetic appearance by covering the existing tooth all the way to the gum line
  • Provide a good seal for a root canal treated tooth
  • Avoid that sunken-in appearance caused by missing teeth usually present in the older population
  • Stabilizing that area of the dental arch to give you a more youthful appearance
  • Crowns are crafted and designed to perfectly fit and blend with your natural teeth
    • Shade selection allows an ideal esthetic result
    • Shape is matched to surrounding teeth which makes the cemented crown seem as a natural unaffected tooth
  • Protect a tooth with a large existing filling from braking
  • Protect a tooth from fracture after root canal treatment is completed

Cost Of A Dental Crown

Dental crown cost can vary greatly across the country. Prices can range from about $600 to as much as $1800. Dental crown prices are higher than cost of a filling for several reasons:

A dental crown is considered a long-term restoration (life span of about 10-20 years. Although the length of time that a crown will last is dependent upon several factors, which include:

  • Quality and frequency of oral hygiene (how often and how well teeth are brushed and flossed)
  • Caries rate (how often cavities may form)
  • How precisely the crown fits on the tooth (more precise fit, less chance of a new cavity)
  • Area in the mouth where the crown is placed (front teeth are usually easier to maintain than back teeth)
  • Area in the mouth where the crown is placed (front teeth are usually easier to maintain than back teeth)

Several factors can determine cost. A dental crown fabricated by a general dentist will on average cost less than a crown fabricated by a prosthodontist. The cost of a crown can also depend on which part of the country you live in, on type of materials used to make the crown, experience of the lab technician who will be fabricating the dental crown and the time spent fabricating it.

Dental insurance usually will cover a portion of the cost of a dental crown. Crowns are classified under major dental work. With most dental insurance plans dental crowns are covered at 50 percent. Although, the coverage can range from 50 to 100 percent. Usually the better dental plans can cover 80 and up to 100 percent of the cost of the crown. You might choose to see a dentist that is a participating provider to obtain better coverage on dental work. Check with your dental insurance company for details.

Different Types Of Dental Crowns

Our teeth are made up of the outer shell of tooth enamel and an inner portion of dentin. Structurally, enamel is very brittle without the support of dentin. As we age our teeth can become weaker due to structural changes. Parafunctional habits such as clenching or grinding of teeth, trauma, and normal and abnormal wear are some of the more common reasons for more compromised teeth. Over time teeth can erode, develop cracks, cavities and wear down which can weaken the overall tooth structure even more. The best way to deal with a compromised, weaken tooth is by covering it with a crown. A dental crown is a restoration, which encircles and partially or completely covers the tooth. The crown will keep the tooth structure intact even under great biting forces. Over the years there have been several crown designs and various materials used. For the purpose of our discussion we will focus on three different types of crown designs:

  • All Metal
  • All porcelain
  • Porcelain fused to metal crowns

All Metal Crowns

Dental crowns made completely out of metal have been used for decades. They vary from crowns made out of base metal alloy to crowns made out of gold alloy. These crowns are very strong and durable. Base metal crowns are usually the least expensive crowns available. The fit of these crowns is acceptable, but does not compare to the fit of a crown made out of gold or porcelain. They also tend to corrode over time. Gold crowns are more inert and stable. Gold alloy crowns are softer and provide an excellent fit. These crowns usually have the best fit out of all different types of crowns, although porcelain crowns are almost to the same standard. A well fitting gold crown can outlast all other crown designs. The tooth requires less preparation or reduction when compared to a porcelain crown.  Another benefit of a gold crown is that it doesn’t cause excessive wear on opposing natural teeth, which is the case with porcelain. The only disadvantage of a gold crown is that it is either yellow or white in color. This makes them less popular than other more aesthetic crowns. They are still commonly done in the back regions of the mouth where they are not as noticeable.

All Porcelain Dental Crowns:

All porcelain dental crowns are tooth colored crowns without any metal substrate. These crowns are highly esthetic and can be fabricated for teeth in anterior (front) and posterior (back) regions. Different porcelain materials is used for crowns requiring more esthetic appearance than for crowns that need to withstand the stress created by forces during chewing.  With the advancements made in the strength of porcelain materials and crown fabrication techniques, porcelain crowns can be comfortably used on any tooth in the mouth. Most porcelain crowns that are made today are milled from a block of porcelain. It is a form of 3-d printing.  This technique reduces or eliminates any structural imperfections that used to occur during previous fabrication methods.  The main advantage of all porcelain crowns is superior esthetics. The color and translucency of these crowns is excellent and esthetically porcelain crowns can look better than natural teeth.  In addition, a porcelain crown can be stained to match the color of your teeth in the mouth. Another advantage is that they are metal free restoration. Color stability throughout the life of the crown is also excellent.

What would be considered a minor disadvantage is that the tooth has to be reduced or shaved down slightly more, as compared to reduction for a metal crown, to provide room for porcelain.  Porcelain crowns perform well when certain parameters are followed. If there is not enough tooth reduction, the crown will be too thin and it can crack.

Porcelain Fused to Metal Dental Crowns:

Porcelain fused to metal dental crowns (PFM) are tooth colored crowns with a metal substrate. These crowns are aesthetic and usually recommended for teeth in posterior regions. The porcelain surface provides an aesthetic appearing crown. The metal substructure provides a good marginal fit of a metal crown as well as structural support for the porcelain. These types of crowns work well in high stress areas where aesthetics is not the primary concern.

With the increased prices of gold in the recent years, full gold crowns can be very expensive. At the same time most patients prefer the pleasing appearance of a tooth-colored restorations. The increased demand for tooth colored, metal-free restorations has improved materials and techniques for fabricating all porcelain crowns. These crowns are becoming a new standard in dentistry.