The crowns or sockets are “covers” which are placed on the teeth and have the morphology of the natural tooth. They are used mainly in cases where the tooth is “damaged” enough that its restoration with a filling is not foreseeable or possible. In order to apply a crown to a tooth, the tooth must first be properly prepared (grinded) by the dentist.
Bridges are used to replace missing teeth. The most common types of bridges require the adjacent teeth to be ground, which may limit their lifespan. This, combined with the development of implants, limits the use of bridges only in certain cases (e.g. when implant placement is not possible).
There are four main types of crowns or bridges:
– Metallic, which can be made of either precious/semi-precious metal or a basic metal alloy. Although the durability of the precious metal has been proven over time, today they are very little used due to their unaesthetic appearance.
– Metal acrylics, which are among the relatively more economical. Although their functionality is similar to the others, aesthetically they are inferior and wear and discolouration over time are quite common.
– Metalloceramics, which are the most common. The ceramic material (porcelain) covers the outer surface of the structure, while inside there is metal. Porcelain, although aesthetically similar to the natural enamel of the tooth, is quite hard and prone to fractures if not properly constructed or if the patient’s occlusion is not properly adjusted.
– All-ceramic, which are made entirely of porcelain. Because there is no metal at all, these constructions are more “transparent” than the others, they do not create shading on the tooth or gums and are therefore considered the most aesthetic.
It should be noted that there are several types of all-ceramic restorations and not all of them yield the same aesthetic image. In addition, the most aesthetic ones require a specialized bonding procedure, which is a demanding process and needs special experience and meticulousness from the dentist.
Finally, there are also restorations made of various other newer materials, such as composite resin, which are sometimes indicated in specific cases.