Ceramic crowns:If you've had a lot of fillings or an injury of some kind which makes veneers impossible, a range of ceramic crowns can be used, such as: metal-free, zirconium ceramic, ceramic fused to metal, or gold Metal-free crowns:These are made of low-melting porcelain and have the nicest appearance since they most closely resemble the natural tooth colour and, unlike crowns on metal, will not be visible near the gum line as the gum recedes with age. Their life-span is similar to that of natural teeth. They are best for people with sensitivity to metals since they are non-allergenic. Zirconium ceramic crowns:This is the latest computer-supported system in metal-free zirconium ceramic. Zirconium is extremely hard and durable, and incomparable with other materials. It is white and translucent, unlike classic porcelain, but its main advantages are its biocompatibility (it is non-toxic and your body will not reject the material), its low temperature conductivity, tightness and colour fastness. As a result, it is an excellent material for cosmetic dental procedures. Crowns on metal:The ceramic is fused onto a metal base and is a tried and tested material for this type of procedure, setting the standard for all subsequent developments in the field. Since the metal construction is opaque, it makes the translucency of the natural teeth difficult to replicate. There is also the risk of metal allergy (to nickel or chrome). This problem can be avoided by using gold as