Crowns or caps have had over a century of success in saving teeth. Fillings are used to restore tooth structure lost to decay or fractures, however, they do not cover and protect the teeth from fracturing like crowns do. There are three major varieties of crowns – cast metal, porcelain-fused-to-metal, and all porcelain.
- Gold Crown, Porcelain-Fused Metal Crown, and All Porcelain Crown
Cast crowns are usually made of gold. They have the longest track record and usually last the longest of the group. This is because there is no veneering surface to fracture and gold is a very tough, inert substance. I have personally observed crowns that have been in patients’ mouths for well over fifty years. The drawback is that they look like gold teeth. The other two varieties have a porcelain outer layer. Porcelain can be constructed to almost perfectly mimic teeth. And the porcelain is extremely tough and color stable. There are still quite a few crowns that I placed over thirty years ago that still look as good now as they did on the day that I put them in. The porcelain is baked onto a metal or porcelain core. The metal can be made much thinner, so it is better for crowns for back teeth. The newer porcelain cores are having very promising results and are excellent for front teeth because light can be transmitted through it giving the crown a natural life-like luster.
Root fractures can be pesky little things to diagnose. A root fracture is a crack in a root of a tooth. It can be either horizontal or vertical in direction.
X-ray of a Horizontal Root Fracture
Horizontal fractures are usually a result of trauma. The survival of the tooth is dependent on where the fracture is located. If it is located in the apical third of the root (apical being the portion toward the tip of the root), then it may be possible to save the tooth. Otherwise it is implant time. Vertical fractures can start in the crown of the tooth, which is most common, or at the tip of the root. Root fractures may or may not have symptoms associated with it. If there are symptoms, they are usually pain while chewing.
Vertical Root Fracture
When fractures are present, they rarely will show on an x-ray, so the usual course of treatment is placing a crown to keep the pieces of the tooth from wedging apart while eating. If this does not work, then root canal treatment is performed. It is, many times, only after the symptoms don’t subside after having a root canal done will a diagnosis be made of a root fracture. Other times there may be a tell-tale thickening of the black line that surrounds the root on an x-ray giving indirect evidence of a root fracture. There is no known way to repair a root fracture and with the advent of long-lasting implants, the best solution of treating a fractured root is by removal of the tooth and placement of an implant.