Porcelain Crowns

   Dental crowns are tooth-shaped coverings placed over teeth that are cracked, badly decayed, damaged or otherwise misshapen. The crown not only strengthens and protects the tooth, it restores its natural size and shape. There are several crown types to choose from, depending on the location of the tooth and your aesthetic preferences, and your cosmetic dentistwill advise you on the best options.

Traditional metal (i.e., gold) crowns are appropriate when appearance is not an important factor, such as for molars which are not highly visible when you smile. Gold is a durable yet workable metal, and a dentist can achieve a very precise fit between crown and tooth. For cosmetic reasons, however (such as with front teeth), porcelain crowns are considered the most aesthetically pleasing, as they are so easily matched in color and appearance to the surrounding teeth. There are several different kinds of porcelain crowns.

All-porcelain crowns have the nicest appearance. This crown can be made from pure ceramic or a reinforced composite resin, and is almost indistinguishable from natural teeth. The new bonding technology involved provides an exceptionally tenacious seal to your tooth. In addition, it is metal-free, and thus satisfies the needs of patients with metal sensitivities. The traditional porcelain crowns were created by what is called the felspathic method, in which 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 desired natural look. A newer type is pressed ceramic porcelain, which is created from a single ingot milled in one piece. The stains and opaques are applied only to the surface of the porcelain.

Another type of porcelain crown is made of porcelain fused to metal, somewhat of a hybrid between metal and all-porcelain crowns. First a shell of metal alloy is made to fit over the tooth, then a layer (or veneer) of porcelain is fused over the metal in a high heat oven, giving a tooth-like appearance. The porcelain veneer may cover only the visible surface of the crown, or the crown may be fully surfaced. Porcelain-fused-to-metal dental crowns can be a good choice for either front or back teeth: they are strong enough to withstand heavy biting pressures while having an excellent cosmetic appearance. They are often not as aesthetically pleasing as all-porcelain crowns, however, and the metal underneath the porcelain layer may start to show near the gum line as gums recede with age or in cases of periodontal disease.