A crown is sometimes termed a "cap" or "jacket." A crown will restore a large filling or a cracked tooth to its original size, shape and tooth color. A crown may be recommended after root canal therapy has been completed, as the tooth tends to become brittle and is more likely to fracture. A crown can strengthen and protect the remaining tooth structure and improves the appearance of your teeth. With the advances in technology, we now have the ability to make ceramic crowns with no metal.
If your smile is in need of a makeover, crowns can provide predictable results. Crowns can give an unattractive tooth back its beautiful shape and color. For smaller or worn down teeth, a crown can restore the natural size of the old tooth. A crown can replace either part of or the tooth's entire structure. For procedures requiring only the areas visible from the outside, a veneer may be an alternative option.
The 'gold' standard. Dental gold is about 60% gold alloy which is meant to match the hardness of the enamel of opposing teeth so both wear about evenly, an important trait. Gold does not tarnish or corrode and has some bacterial-inhibiting quality. Gold crowns are strong and will not break. However, gold crowns obviously are not considered aesthetic; they are gold colored. Usually, gold crowns are used for lower back molars because they aren't as noticeable.
The most common type of crown and has a proven track record. PFM crowns are fairly aesthetic and they look like real teeth. However, the margins or borders may appear dark because PFM crowns have a metal substructure with layers of porcelain fired over the substructure. Porcelain is very hard, much harder than natural enamel and may cause excessive wear of the enamel of opposing teeth. Porcelain may break with extreme biting forces.