When teeth are heavily decayed they may be too weak to survive with just a filling. By placing a crown, a tooth may be given a new lease of life. Even when a single tooth is lost a denture may not be required as a bridge can be made which spans the gap with a tooth attached to those next to the space. Sometimes when a single small tooth is lost at the front of the mouth a simple bridge can be made which has ‘wings’ that are glued to the back of the adjacent teeth. This results in less tooth being damaged by the drill.
When a tooth is heavily decayed it is more likely to fracture and lose considerable tooth substance. The greater risk is that a fracture line may go below the margin of the gum which makes restoration more difficult or near impossible. Crowns may be made from several different materials, gold and porcelain being the most common types.
Porcelain Fused to Metal (PFM) Crowns:
Porcelain fused to metal crowns are more affordable than all ceramic crowns. Even though they are not as aesthetic as porcelain crowns they are still a good candidate for back teeth restoration. Read this article to find out what the advantages and disadvantages of PFM crowns are.
Porcelain fused to metal crowns (or PFM crowns) can be referred to as full-cast crowns which has porcelain fused on most or all parts of the tooth. They are a hybrid between porcelain and metal crowns. The entire crown has a metal layer underlying and porcelain / ceramic on top of it.
The metal framework is thin, strong, and perfectly fits the prepared teeth. It’s a combination of different types of alloys which are designed such that they bond very well with the porcelain. Metal alloys with a high melting temperature are used to fuse porcelain to the surface and preventing the metal from melting. This ensures the porcelain to bond without changing its color.