Crowns

What are dental crowns?

Crowns are a type of dental restoration which, when cemented into place, fully cup over the portion of a tooth which lies at and above the gum line. In comparison, fillings are dental restorations that are used to fill in or cover over just a portion of a tooth. Since dental crowns encase the entire visible aspect of a tooth, a dental crown in effect becomes the tooth's new outer surface.

Crowns can be made out of porcelain (or some other ceramic material), gold (or metal alloys), or a combination of both. Dental crowns are often referred to as "dental caps" or "tooth caps".

Why do teeth need dental crowns?

A dentist might recommend placing a dental crown for a variety of reasons but, in general, most of these reasons will usually fall within one of the following basic categories:

• To restore a tooth to its original shape.
• To strengthen a tooth.
• To improve the cosmetic appearance of a tooth.

How are dental crowns used to restore a tooth's shape?

Since a dental crown cemented into place essentially becomes the new outer surface of the tooth it is easy to imagine how the placement of a crown can restore a tooth to its original shape. Dental crowns are often made for teeth that have worn excessively, have broken, or else have had large portions destroyed by tooth decay.

Conceivably the placement of a dental filling could, as an alternative, be used as a means to restore a tooth's shape. Dental crowns however offer a big advantage to your dentist over dental fillings by way of the fact that they are fabricated "away from your mouth". By this we simply mean that dental crowns are fabricated in a dental laboratory (by a dental technician who uses plaster molds your teeth made by your dentist). Dental fillings, in comparison, are created "in your mouth" by way of your dentist placing the filling material directly upon your tooth.

When a dental crown is made the dental laboratory technician can visualize and examine all aspects of your bite and jaw movements, from a variety of angles, and sculpt your dental crown so it has the perfect anatomy. In some cases this anatomy will be even more ideal than your tooth's original shape. When placing a dental filling a dentist has less control over the final outcome of the shape of your tooth because it is often difficult for them to visualize, evaluate, and access to the tooth on which they are working.

How can dental crowns be used to improve the cosmetic appearance of teeth?

Since dental crowns cup over teeth, any dental crown that has a porcelain surface can be used as a way to idealize the cosmetic appearance of a tooth. Possibly you have heard it said (especially in past decades) that such-and-such movie star has had their teeth "capped" (the term "cap" used here is equivalent to the term "dental crown"). This simply means that the person has obtained their "Hollywood smile" by way of having dental crowns placed.

Actually, getting your teeth "capped" so just to improve their appearance can at times be a very poor choice. Dental crowns are best utilized as a way to improve the cosmetic appearance of a tooth when the crown simultaneously serves other purposes also, such as restoring a tooth to its original shape (repairing a broken tooth) or strengthening a tooth (covering over a tooth which has an excessively large filling).

In general, dental crowns probably should not be used as a means to improve the appearance of a tooth if there is any other alternative dental treatment that could equally satisfactorily achieve the same cosmetic results. This is because a dentist must grind a significant portion of a tooth away when a dental crown is made. If a more conservative dental procedure could equally well improve the tooth's appearance, such as a porcelain veneer, dental bonding, or even just teeth whitening, then it is usually best to consider that treatment option first.

How do dental crowns strengthen teeth?

The strengthening capability of dental crowns is related to the fact that they cup over and encase the tooth on which they are placed, thus serving as a splint which binds the tooth together. Dental crowns are a very important means by which a dentist can strengthen a tooth.

In contrast, dental fillings, especially large ones, often have a weakening effect on the teeth in which they are placed. Dental fillings rely on a tooth's remaining structure to hold and support them. Fillings, in general, don't strengthen a tooth and don't protect a tooth from the forces generated by biting and chewing.