Questions you Should Ask Your Dentist About your Dental Restoration
By: Manny Chopra, BDS, DMD, FADI, FICD
Dental Crowns (Caps)
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 more than one cusp of a tooth breaks, on a tooth with a root canal or an intact tooth, a crown may be required to give support to the remaining tooth structure.
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.
How is a Crown made for my tooth?
After your dentist has anesthetized the tooth, he will grind and shape the tooth, then make an impression of the tooth and then send the impression to a quality dental laboratory to fabricate the crown. You will leave the office with a temporary crown to wear while the permanent crown is being made – this takes about two weeks. When the crown comes back from the lab, after checking the fit, contacts, bite and color, your dentist will then cement the crown onto your tooth. Typically, only two visits are required for this part of the procedure. Often, if your tooth is badly broken down, the tooth may need a buildup prior to starting the crown this provides a stable foundation for the new crown. Tooth crowns typically last for 8-12 years, if not longer.
What types of crowns are available?
There are basically three types of crowns, those made of metal (gold based, all metal, and stainless steel), ceramic crowns and metal ceramic crowns. Gold and metal-ceramic crowns are extremely durable and are normally used on your back molars, where the forces from chewing and grinding are heavier. Ceramic crowns were used primarily for front teeth, since they can best resemble the natural tooth color. With newer
ceramic technology, we are now placing all ceramic crowns on back teeth, as they can provide the same strength and durability of a metal-based crown.
All Ceramic/Resin Crown
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 newer bonding techniques currently available provide an exceptional bond to your tooth. This is metal-free option, and may be preferred by someone allergic to certain metal alloys.
Gold or base metal crowns are appropriate when appearance is not a priority to you. The gold metal is extremely workable making gold crowns a more precise fit than any other type. There is no risk for chipping of the porcelain in this option.
Porcelain and Metal (Metal Ceramic) Crowns
These types of crowns are the typical crown which most people currently receive. Here, a metal substructure is first fabricated, then porcelain is baked on the metal to provide for natural esthetics. These crowns come in a variety of shade combinations. Because of the underlying metal 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 if it recedes with age.
Which type of crown is best for me?
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 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.
Advantage: The preparation of a tooth for a metal crown is the simplest and least complicated preparation as there is minimal tooth structure removal with as much as possible of the healthy tooth structure remaining untouched. While porcelain is hard by comparison, it may cause wear on opposing teeth over the years where gold is not as likely to do so. Gold is also easier to fit to the area where the tooth and crown meet for a better fit. Gold is also a healthier environment for the gum tissue.
Disadvantage: The biggest disadvantage to gold crowns is the cosmetic aspect, unless it is being used in the back of your mouth.
Advantage: Porcelain crowns or new reinforced resin are considered to be the most aesthetically pleasing, as it is so easily matched in color to the surrounding teeth.
Disadvantage: The thickness of the porcelain required for pleasing aesthetics also requires that more tooth structure needs to be removed. Gingival inflammation occasionally appears to be more common with porcelain crowns than gold crowns.
Metal Ceramic Crowns
Advantage: Porcelain fused-to-metal crowns have a very natural appearance.
Disadvantage: They have a metal substructure and require an opaque layer of porcelain to mask the metal color. 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 if it recedes with age.
This article is intended to provide you with some crown options to consider, however, everyone’s situation and needs are different, please discuss these in greater detail with your dentist. Please make sure that you fully understand the choices available to you, and that all of your questions get addressed.
Dr. Manish Chopra of Cincinnati, Ohio is a prosthodontist in private practice. He serves as a dentist for military personnel at Complete Mobile Dentistry/Logistics Health International and as a volunteer dentist at Good Samaritan Hospital Free Health Center. He earned his bachelor’s degree from Government Dental College and Hospital, his DMD degree from Washington University, and his Certificate in Prosthodontics from Indiana University School of Dentistry.
Dr. Chopra is a past president of the Cincinnati Dental Society, current member of the American Dental Association (ADA) Council on Dental Practice, treasurer for the Ohio Dental Association (ODA), current chair of the ODA’s Council on Dental Care Programs and Dental Practice, and current trustee on the ODA Foundation Board of Trustees. He is a fellow of the International College of Dentists, American College of Dentists, and Academy of Dentistry International.