The metal free dental crowns can be made from:
- full ceramics – pure porcelain crowns
- zirconium with CAD/CAM technology (computer controlled, micron accuracy)
Traditionally, crowns and bridges are made of a metal base (can be ordinary metal or noble metal) and porcelain fused on top. The porcelain layer resembles real teeth and covers the metal structure. Crowns are used when the damaged tooth may be impossible to restore to its correct form using fillings, inlays or onlays. Crowns are also used to support dental bridges. To prepare the tooth, the dentist drills some tooth and core away, takes an impression and records the shape and shade of the teeth before writing a prescription for the dental lab to follow. A temporary crown is placed on the tooth until the final one is ready. The last step is when the permanent crown is cemented over the tooth.
The restoration don’t include metal, every layers are tooth colored. This type of restoration perfectly imitates the layers and natural transparency of our own teeth; so these restorations are perfectly aesthetic and also very durable. The most perfect micron precision border seal you can achieve with the today’s most advanced CAD/CAM computer controlled system. Based on the prepared sample of the silicon impression of the tooth we digitalize it with the help of a three dimensional laser scanning machine and the computer controlled bur machines make the zirconium dioxide skeleton, without human touch, possibility of error is excluded. While by the pantograph controlled technology the zirconium dioxide skeleton is made by handmade. The result is the perfect precision and the high level of the unique combination of aesthetics.
Zirconium oxide
Zirconium dioxide is a high strength ceramic material, which is used for high-tech applications, e.g. int he aerospace industry. It is a chemical compound of the rare element zirconium and oxygen. Its chemical formula is ZrO2. It is often referred to as zirconium oxide or zircon oxide.
For who recommend we the zirconium oxide crown?
- the replacement of the old ceramo-metallic crown was necessary (the is grey, the metal strip is visible)
- root canal treated, discolored tooth
- edentulous area (the most aesthetic restoration is the crown)
- gingival inflammation, bad breath elimination
- in the case of implant restorations (recommended for zirconium implant to the zirconium structure)
The benefits of the zirconium oxide crown:
- it is aesthetic and ultra-precise, because the zirconium prosthesis is are made with the above mentioned so called CAD/CAD procedure
- realistic: a zirconium prosthesis is practically indistinguishable from the real teeth
- reliable, long lasting: in the past 10 years there was made millions of zirconium crowns and fixed partial dentures around the world, to the biggest satisfaction of the patients. A lot of clinical studies have shown that the zirconium restorations are very reliable; they serve for many years and decades.
- it is biocompatible: the zirconium oxide does not contain any metal, so the risk of the allergy is practically excluded. Meets to the stringent requirements related to the implantology, so the gingival is perfectly healthy around the crowns or the fixed partial dentures.
- due to the shoulder preparation the gingival remains healthy pink, it won’t be inflamed, won’t be turn blue
Why do these dentures look so natural?
The ceramic substructure is coated with a so-called veneering ceramic which is painstakingly built up by the dental technician to match the appearance and shade of the individual patient's natural teeth. The result is a full-ceramic tooth that only an expert can distinguish natural dentition. In order to protect the opposing teeth, the veneering ceramic is softer than the supporting substructure. The substructure itself would be too hard.
The veneering ceramic is supplied as a powder and is mixed with a special liquid and applied with a brush. It comes in a variety of colours. However, these are only intended as an aid to the dental technician, so that he or she knows which material is being used for each layer.
In order to lend an artificial tooth a natural appearance, it is necessary to use a number of different ceramic materials to provide various shades of white and differing degrees of brightness. When the layers of ceramic powder have been built up, the restoration is baked in a furnace and the colours disappear. The crown is then left with different degrees of brightness and shades of white and the overall effect is a denture that perfectly matches your natural teeth. The finished restoration is then fitted by your dentist.
The zirconium dioxide skeleton is actually a metal free skeleton, its material is similar to the ceramic, but it is much stronger and less fragile. Its bending strength is much greater than the traditional complete porcelain veneer crown. Due to the white, but colorable skeleton the contact of the crowns with the peripheral part of the gingival becoming free don’t cause aesthetic complaint over time (which is normal), it provides longer comfort for the patients. One of its highlighted advantages is that don’t irritating the mucous membrane contacting with the crown peripheral. We recommend it: for discolored, root canal treated tooth, for veiled teeth fitted with metallic pin, for replacement of old restorations (because of the above mentioned metal border). In addition we recommend to the front area, due to aesthetic reasons, but thanks to the continuous technical development to the lateral (chewing) area, for replacement of 2-3 edentulous area.
