A crown is a custom laboratory made restoration that fits over your tooth making it strong and having the shape of a natural tooth.
They are used for several reasons:
- as a protective cover for badly decayed or fractured teeth or the worn dentition
- as a permanent restoration for teeth with large fillings
- to correct minor problems in natural teeth like spacing, irregular shape or severe discolouration
Crowns can be made from a variety of materials. They can be made from ceramic or metal alloys. A combination of metal and ceramic is also possible to maximise strength and simulate the appearance of natural teeth. New materials are being developed all the time.
- Porcelain bonded to precious metal. These are the most common crowns made. The porcelain on the outside looks like tooth and it is fused to precious metal on the inside which gives it strength. They are strong and beautiful like natural teeth. The downside of these crowns is that you can in some cases over a period of many years, due to small changes in the position of the gum get a dark line showing at the junction of the crown and tooth. At the back of the mouth a slightly dark shadow is not usually a problem but it may be at the front of the mouth especially if you have a high lip line and show the tops of the teeth when you smile.
- For optimum aesthetics I instruct my technicians to take the porcelain to the buccal shoulder of the tooth preparation, this works extremely well. However, I would recommend all ceramic restorations for anterior teeth so that there is no chance of a dark shadow occurring.
- All ceramic crowns. This is a relatively new material; they look most like the natural tooth because of the way the light passes through it, really beautiful, life-like crowns. The material is very strong which means it is suitable for most people in most areas of the mouth. It is more expensive.
- Gold crowns. These are still the ‘gold’ standard, shiny yellow gold is a brilliant material for making crowns. It is very strong and very useful where we have short teeth at the back of the mouth. Not everyone however wants to show gold when they smile so it is usually used on the back molar teeth.