Dental Center of Simi Valley

As we age, many of us find ourselves with teeth that are no longer structurally sound. Root canals, lost fillings, decay below a filling, chipping and cracking of the enamel are all things that can lead to large scale defects in a tooth's surface. When the entire surface of the tooth is a problem, but the root system is intact, a crown might be just what the dentist orders.

What are Tooth Crowns?

Grinding your teeth, an improper bite, age, fillings and tooth decay can all be contributing factors in the wearing down, cracking or breakage of your teeth. Dental crowns cover the entire visible surface of your affected tooth and add strength, durability and tooth stability.

Who is a candidate for Tooth Crowns?

Dr. Vahe Antanesian will usually be able to spot problem areas in your mouth that might lead to tooth damage and a need for crowns. Chewing patterns play a big role as well. By selectively grinding the tips of your middle and back teeth (called cusps) will alter your bite to reduce the stress on at-risk teeth.

In other instances, crowns are used to replace a actual missing tooth. These crowns are anchored to the teeth on either side, with a bridge section connecting the two crowns. Instead of bridges, single tooth dental implants may be used that eliminate the need for supporting the crowns.

How are Tooth Crowns Attached to your Tooth?

Dr. Vahe Antanesian will make an impression of the tooth and a dental laboratory will create the crown. You will typically leave the office with a temporary crown to wear while the permanent crown is being made - this takes about two weeks. The permanent crown is then cemented onto your tooth. Typically, only two visits are required for this part of the procedure. Often, a preliminary restoration of your tooth may be needed before a crown can be placed. To stabilize your tooth, a filling must first be put in place prior to placing a crown due to the loss of original tooth structure. Tooth crowns usually last ten to fifteen years.

Be sure to discuss with your cosmetic dentist that the cement color used for your permanent crown will be the same as used for your temporary crown. A try in paste is used for this purpose. The color of the cement does affect the overall color of a porcelain crown, so this needs to be discussed long before your temporary crown is placed.

In some cases your cosmetic dentist may choose to use a Flipper instead of a temporary crown. A Flipper is a false tooth to temporarily take the place of a missing tooth before the permanent crown is placed. A Flipper can be attached via either a wire or a plastic piece that fits in the roof of your mouth. Flippers are meant to be a temporary solution while awaiting the permanent crown.

As the illustration above indicates:

1) a tooth presents with a large cavity or broken portion of tooth structure. This tooth is vulnerable to further decay and fracture.

2) the dentist will 'prepare' or shape the tooth for a crown. In preparing the tooth, the dentist will incorporate resistance and retention features in order for the crown to stay in place. These features vary in every tooth and are determined by the type of bite you have. An impression of the prepared tooth is taken and sent to a dental laboratory for processing.

3) a crown is then fabricated in the dental laboratory with instruction from the dentist such as type of crown and shade or color of the tooth. The crown is then cemented in place by the dentist. A temporary crown is placed while the laboratory is constructing the crown.

Types of Tooth Crowns

There are basically 2 types of crowns, those made of ceramic crowns and metal-ceramic crowns. Metal-ceramic crowns are extremely durable and are normally used in molars, where the forces from chewing and grinding are most prevalent. Ceramic crowns are used primarily for front teeth, since they can best resemble the natural tooth color.

All Porcelain Crowns

The new reinforced resin or bonded all-porcelain type of crown has the nicest appearance. This crown can be made from pure ceramic or a new reinforced composite resin, and is almost indistinguishable from natural teeth. The new bonding technology involved provides an exceptional bond your tooth. It is metal-free, and thus satisfies the needs of patients with metal sensitivities. When correcting your back teeth with bonding, the cosmetic dentist will perform a tooth colored-onlay. This type of procedure is used to correct only those parts of the tooth that are in need. This is a metal-free procedure.

Porcelain fused to Metal Crowns

For a very natural appearance, porcelain fused to metal crowns are the answer. However, they have a metal substructure and require an opaque below the porcelain. This can make the translucency of natural teeth difficult to replicate. Occasionally a darker line will be visible at the edge of the crown, near to your gum when it recedes with age.

Types of Porcelain

There are basically two types of porcelain you're likely to hear and read about most - the felspathic and pressed ceramic porcelains. The felspathic type is the original method that has been around for 20 years. A Ceramist in a dental lab bakes porcelain onto tin foil and then heats it in an oven. The Ceramist is able to create tints and opaques inside the porcelain to give the natural look we seek.

Pressed ceramic is created from a single ingot. The single ingot is milled in one piece to create the desired shape. The stains and opaques are applied only to the surface of the porcelain to give a natural look.

Zirconium oxide - One of the most difficult areas in dentistry today is the restoration of dental structures with biocompatible materials that are strong enough to withstand the forces of chewing (500-1000lbs pressure on molar teeth). Recent technology from Germany now offers a material that has overcome most of the pitfalls of present day products. Patients now have a choice of a material that is esthetic, strong, pure, biocompatible and capable of being used for single and long span dental bridgework. That material is called Zirconium oxide.

Pros and Cons of Dental Crowns Types

Tooth crowns in general add a good deal of strength to weakened or worn teeth. Depending on your habits and the condition of your gums, there can be some drawbacks. Your cosmetic dentist will advise which is best for you given many factors, including how important appearance is to you. The following are the advantages and disadvantages of the most common crown types.

Porcelain Crowns

Advantage: Porcelain crowns or new reinforced resin are considered to be the most aesthetically pleasing, as it is so easily matched in colour to the surrounding teeth.

Disadvantage: The thickness of the porcelain required for pleasing aesthetics also requires that more tooth structure needs to be removed. It is more difficult for your cosmetic dentist to get an ideal fit where your gum meets the crown. Gingival inflammation appears to be more common with porcelain crowns than gold crowns. All-porcelain crowns require a higher skill level from your dentist and lab.

Porcelain Fused-to-Metal Crowns

Advantage: Porcelain fused-to-metal crowns have a very natural appearance.

Disadvantage: They have a metal substructure and require an opaque below the porcelain. This can make the translucency of natural teeth difficult to replicate. Occasionally a darker line will be visible at the edge of the crown, near to your gum when it recedes with age.