Porcelain crowns are caps that completely cover the tooth simulating the whole external shape of the natural tooth. They are between 1 and 1.2 mm thick. They can be made from porcelain only or they can have the centre made form a different material for further consistency, such as metal or, lately, alumina or zirconia.
The technique step-by-step
EThe tooth must be reduced all around by 1.0-1.2 mm, with a cone shape, so that when fitting the crown it slides down the tooth’s sides until it fits perfectly and it’s hermetically sealed. Once preparation is over, a mould is made and a provisional crown is fitted. When all the different fittings are done, it’s bonded to the tooth using adhesive or dental cement.
They are used when a large amount of dental tissue has been lost due to large cavities or injuries because a veneer or a filling would be very difficult to keep in place due to the loss of the tooth structure. They are also used in cases of root canal treated teeth because they can give consistency to the whole tooth and can avoid future fractures, as root canal treated teeth are quite week after treatment.
Porcelain crowns are used to cover weak teeth; they offer the beauty of porcelain and the resistance of metal. The tooth only needs to be reduced by 1.2 mm all around in order to create the necessary space for the components of the crown.
Nowadays, there is more demand for porcelain crowns without metal as the result is aesthetically better.
Zirconium is a material which is highly biocompatible; it is very tough and it is also white, making it a material with excellent functional and aesthetic properties for use in dentistry.
It is currently the material that achieves the best results in tooth reconstructions which would have previously needed less aesthetically appealing metallic components.
Zirconium has bending strength of 900 MPa, a modulus of elasticity of 200 GPa and hardness of 1300 Kg/mm2.
These properties make it an excellent material to bear mastication.
Crowns over implants
Dental implants are titanium artificial roots which cover the aesthetic, chewing and phonetic needs of people who have lost their natural teeth.
Patients who have lost one or several teeth ask for the easiest treatment in order to solve their problem, aesthetically and functionally. They want to avoid work on adjacent teeth, needed for a bridge, and this can only be achieved through dental implants.
Many materials have been used since implants were first used, but nowadays titanium is the most widely used material.
Titanium is not only a material which is highly biocompatible with the human body, it also has the ability to join the bone easily. This way, the bone accepts the titanium as if it was really a part of the body, resulting in biological welding.
The prostheses (caps), which act exactly the same way as natural teeth, are fitted when the implants have healed.
Implants will allow us to chew comfortably, smile and speak as we would do with our own teeth.
Sometimes, in specific cases, a provisional prosthesis can be fitted the same day the patient undergoes implant surgery. This type of treatment offers more comfort for the patient straight away, but it isn’t always possible.